amazing nature

Mono

2009-04-09T13:31:00.000-07:00

Mono Lake is an alkaline and hypersaline lake in Mono County, California that is a critical nesting habitat for several bird species and is an unusually productive ecosystem.

Geology

Mono Lake is believed to have formed at least 760,000 years ago, dating back to the Long Valley eruption. Sediments located below the ash layer hint that Mono Lake could be a remnant of a larger and older lake that once covered a large part of Nevada and Utah, making it among the oldest lakes in North America.

Mono Lake is a terminal lake in a watershed fed from melting runoff with no outlet. Dissolved salts in the runoff thus remain in the lake and raise the pH and the salt concentration.

Mono Lake is in a geologically active area at the north end of the Mono-Inyo Crater volcanic chain of the Long Valley Caldera. The geological activity is caused by faulting at the base of the Sierra Nevada, and is associated with the crustal stretching of the Basin and Range Province.

Volcanic activity continues in the Mono Lake vicinity: the most recent eruption occurred 350 years ago at Paoha Island in Mono Lake. Panum Crater (on the south shore of the lake) is an excellent example of a combined rhyolite dome and cinder cone.

Limnology

The lake contains approximately 280 million tons of dissolved salts, with the salinity varying on the amount of water in the lake at any given time. Before 1941, the salinity was approximately 50 grams per liter (g/l) (compared to a value of 31.5 g/l for the world's oceans). In January 1982, when the lake reached its lowest level of 6,372 feet (1,942 m), the salinity had nearly doubled to 99 g/l. In 2002, it was measured at 78 g/l and is expected to stabilize at an average 69 g/l as the lake replenishes over the next 20 years.

An important aspect of the end of water diversions was an onset of "meromixis" in Mono Lake. Prior to the end of water diversions, Mono Lake was typically "monomictic," which means that at least once each year the deeper waters and the shallower waters of the lake mixed thoroughly, thus bring oxygen and other nutrients to the deeper waters. In meromictic lakes, the deeper waters do not undergo this mixing. In meromictic lakes, the deeper layers are more saline than the water near the surface, and are typically nearly devoid of oxygen. As a result, meromixis greatly changes a lake's ecology.

Mono Lake has undergone meromictic periods prior to the one commencing in 1994, and this most recent meromictic period brought on by the end of water diversions ended by 2004.

Ecology

The hypersalinity and high alkalinity (pH=10 or equivalent to 2.5 grams of NaOH per liter of water) of the lake, means that no fish are native to the lake. An attempt by the California Department of Fish and Game to stock the lake failed. The lake is famous for the Mono Lake brine shrimp, Artemia monica, a tiny species of brine shrimp, no bigger than a thumbnail, that are found nowhere else on earth. During the warmer summer months, an estimated 4-6 trillion brine shrimp inhabit the lake. The brine shrimp feed on microscopic planktonic algae which reproduce rapidly during winter and early spring after winter runoff brings nutrients to the surface layer of water. By March the lake is "as green as pea soup" with photosynthesizing algae. Brine shrimp has no food value for humans, but is a staple for birds of the region. Also an important food source, alkali flies (Ephydra hians) live along the shores of the lake and walk underwater encased in small air bubbles to graze and to lay eggs. The whole food chain of the lake is based on the high population of single-celled algae present in the warm shallow waters.

Mono Lake is a vital resting and eating stop for migratory shorebirds and has been recognized as a site of international importance by the Western Hemisphere Shorebird Reserve Network. Nearly 2,000,000 waterbirds, including 35 species of shorebirds, use Mono Lake to rest and eat for at least part of the year. Some shorebirds that depend on the resources of Mono Lake include American Avocets, Killdeer and sandpipers. Over 1.5 million Eared Grebes and phalaropes use Mono Lake during their long migrations.

Late every summer tens of thousands of Wilson's Phalaropes and Red-necked Phalaropes arrive from their nesting grounds, and feed until they continue their migration to South America or the tropical oceans respectively.

In addition to migratory birds, a few species spend several months to nest at Mono Lake. Mono Lake is the second largest nesting population of California Gulls, second only to the Great Salt Lake in Utah. After abandoning the landbridged Negit Island in the late 1970s, California gulls have moved to some nearby islets and have established new, if less protected nesting sites. Cornell University and Point Reyes Bird Observatory have continued the study of nesting populations on Mono Lake that was begun over 20 years ago. Snowy Plovers also arrive at Mono Lake each spring to nest along the remote eastern shores.

credited to wikipedia

Everglades

2009-04-06T12:53:00.001-07:00

The Everglades are a subtropical wetland located in the southern portion of the U.S. state of Florida, comprising the southern half of a large watershed. The system begins near Orlando with the Kissimmee River, which discharges into the vast but shallow Lake Okeechobee. Water leaving the lake in the wet season forms a slow-moving river 60 miles (97 km) wide and over 100 miles (160 km) long, flowing southward across a limestone shelf to Florida Bay at the southern end of the state. The Everglades are shaped by water and fire, experiencing frequent flooding in the wet season and drought in the dry season. Writer Marjory Stoneman Douglas popularized the term "River of Grass" to describe the sawgrass marshes, part of a complex system of interdependent ecosystems that include cypress swamps, the estuarine mangrove forests of the Ten Thousand Islands, tropical hardwood hammocks, pine rockland, and the marine environment of Florida Bay.

Human habitation in the southern portion of the Florida peninsula dates to 15,000 years ago. Two major tribes eventually formed in and around Everglades ecosystems: the Calusa and the Tequesta. After coming into contact with the Spanish in the late 16th century, both tribes declined gradually during the following two centuries. The Seminoles, a tribe of Creeks who assimilated other peoples into their own, made their living in the Everglades region after being forced there by the U.S. military in the Seminole Wars of the 19th century. Draining the Everglades was first suggested in 1848, but was not attempted until 1882. Canals were constructed throughout the first half of the 20th century, and spurred the South Florida economy, prompting land development. However, problems with canals and floods caused by hurricanes forced engineers to rethink their drainage plans. In 1947, Congress formed the Central and Southern Florida Flood Control Project, which built 1,400 miles (2,300 km) of canals, levees, and water control devices. The South Florida metropolitan area grew substantially at this time and Everglades water was diverted to cities. Portions of the Everglades were transformed into farmland, where the primary crop was sugarcane. Approximately 50 percent of the original Everglades has been turned into agricultural or urban areas. When the construction of a large airport was proposed 6 miles (9.7 km) north of Everglades National Park, an environmental study predicted it would destroy the South Florida ecosystem. Restoring the Everglades then became a priority.

National and international attention turned to the environment in the 1970s, and UNESCO and the Ramsar Convention designated the Everglades as one of only three wetland areas of global importance. Restoration began in the 1980s with the removal of a canal that straightened the Kissimmee River. The water quality of Lake Okeechobee, a water source for South Florida, became a significant concern. The deterioration of the environment was also linked to the diminishing quality of life in South Florida's urban areas. In 2000, a plan to restore the Everglades was approved by Congress; to date, it is the most expensive and comprehensive environmental repair attempt in history. The Comprehensive Everglades Restoration Plan was signed into law, but the same divisive politics that had affected the region for the previous 50 years have compromised the plan.

Origin of the word

The first written record of the Everglades was on Spanish maps made by cartographers who had not seen the land. They named the unknown area between the Gulf and Atlantic coasts of Florida Laguna del Espíritu Santo ("Lake of the Holy Spirit"). The area appeared on maps for decades without being explored. Writer John Grant Forbes stated in 1811, "The Indians represent [the Southern points] as impenetrable; and the [British] surveyors, wreckers, and coasters, had not the means of exploring beyond the borders of the sea coast, and the mouths of rivers".

British surveyor John Gerard de Brahm, who mapped the coast Florida in 1773, called the area "River Glades". Both Marjory Stoneman Douglas and linguist Wallace McMullen suggest that cartographers substituted "Ever" for "River". The name "Everglades" first appeared on a map in 1823, although it was also spelled as "Ever Glades" as late as 1851. The Seminoles call it Pa-hay-okee, meaning "Grassy Water", and the region was labeled "Pa-hai-okee" on an American military map in 1839, although it appeared as "Ever Glades" throughout the Second Seminole War.

Geology

The geology of South Florida, together with a typical subtropical climate of warm, wet features, provides conditions well-suited for a large marshland ecosystem. Layers of porous and permeable limestone create water-bearing rock, soil, and aquifers that affect the climate, weather, and hydrology of South Florida. The properties of the rock underneath the Everglades can be explained by the geologic history of the state. The crust underneath Florida was at one point part of the African region of the supercontinent Gondwana. About 300 million years ago, North America merged with Africa, connecting Florida with North America. Volcanic activity centered around the eastern side of Florida covered the prevalent sedimentary rock with igneous rock. Continental rifting began to separate North America from Gondwana about 180 million years ago. When Florida was part of Africa, it was initially above water, but during the cooler Jurassic Period, the Florida Platform became a shallow marine environment. Through the Cretaceous Period, most of Florida remained a tropical sea floor of varying depths. The peninsula has been covered at least seven times by seawater since the bedrock formed.

Climate

The climate of South Florida is noted for its variability, as average annual temperatures range from 60 °F (16 °C) to 80 °F (27 °C). Temperatures in summer months typically exceed 90 °F (32 °C), although coastal locations are cooled by winds from the Gulf of Mexico and the Atlantic Ocean. Freezing in winter months occurs with varying severity and frequency. The region's subtropical to tropical climate features a 7-month wet season from April through October, when 75 percent of precipitation is related to tropical cyclones and thunderstorms. Only 25 percent of the annual precipitation falls during the dry season from November to March, usually sparked by cold fronts tracking southward. Annual rainfall averages approximately 62 inches (160 cm), with the Eastern Coastal Ridge receiving the majority of precipitation and the area surrounding Lake Okeechobee receiving about 48 inches (120 cm).

credited to wikipedia

Mammoth Cave

2009-04-03T12:05:00.000-07:00

Mammoth Cave National Park is a U.S. National Park in central Kentucky, encompassing portions of Mammoth Cave, the longest cave system known in the world. The official name of the system is the Mammoth-Flint Ridge Cave System for the ridge under which the cave has formed. The park was established as a national park on July 1, 1941. It became a World Heritage Site on October 27, 1981, and an international Biosphere Reserve on September 26, 1990.

The park's 52,830 acres (214 km²) are located primarily in Edmonson County, Kentucky, with small areas extending eastward into Hart County and Barren County. It is centered around the Green River, with a tributary, the Nolin River, feeding into the Green just inside the park.

Limestone labyrinth

Mammoth Cave developed in thick Mississippian-aged limestone strata capped by a layer of sandstone, making the system remarkably stable. It is known to include more than 360 miles (580 kilometers) of passageway; new discoveries and connections add several miles to this figure each year. Mammoth Cave National Park was established to preserve the cave system.

The upper sandstone member is known as the Big Clifty Sandstone: thin, sparse layers of limestone interspersed within the sandstones give rise to an epikarstic zone, in which tiny conduits (cave passages too small to enter) are dissolved by the natural acidity of groundwater. The epikarstic zone concentrates local flows of runoff into high-elevation springs which emerge at the edges of ridges. The resurgent water from these springs typically flows briefly on the surface before sinking underground again at elevation of the contact between the sandstone caprock and the underlying massive limestones. It is in these underlying massive limestone layers that the human-explorable caves of the region have naturally developed.

The limestone layers of the stratigraphic column beneath the Big Clifty, in increasing order of depth below the ridgetops, are the Girkin Formation, the St. Genevieve Limestone, and the St. Louis Limestone. For example, the large Main Cave passage seen on the Historic Tour is located at the bottom of the Girkin and the top of the St. Genevieve Formation.

Each of the primary layers of limestone are divided further into named geological units and subunits. One area of cave research involves correlating the stratigraphy with the cave survey produced by explorers. This makes it possible to produce approximate three-dimensional maps of the contours of the various layer boundaries without the necessity for test wells and extracting core samples.

The upper sandstone caprock is relatively hard for water to penetrate: the exceptions are where vertical cracks occur. This protective role means that many of the older, upper passages of the cave system are very dry, with no stalactites, stalagmites, or other formations which require flowing or dripping water to develop.

However, the sandstone caprock layer has been dissolved and eroded at many locations within the park, such as the Frozen Niagara room. The "contact" between limestone and sandstone can be found by hiking from the valley bottoms to the ridgetops: typically, as one approaches the top of a ridge, one sees the outcrops of exposed rock change in composition from limestone to sandstone at a well-defined elevation.

At one valley bottom in the southern region of the park, a massive sinkhole has developed. Known as "Cedar Sink," the sinkhole features a small river entering one side and disappearing back underground at the other side.

Mammoth Cave is home to the endangered Kentucky cave shrimp, a sightless albino shrimp.

Biology and ecosystem

The bats that inhabit the caverns are the following: Indiana bat (Myotis sodalis), Gray bat (Myotis grisescens), Little brown bat (Myotis lucifugus), Big brown bat (Eptesicus fuscus), and the Eastern pipistrelle bat (Pipistrellus subflavus).

All together, these and more rare bat species such as the Eastern Small-footed Bat had estimated populations of 9-12 million just in the Historic Section. While these species still exist in Mammoth Cave, their numbers are now no more than a few thousand at best. Ecological restoration of this portion of Mammoth Cave, and facilitating the return of bats, is an ongoing effort. Not all bat species here inhabit the Cave; the red bat (Lasiurus borealis) is a forest-dweller, found underground only rarely.

Other animals which inhabit the caves include: two genera of Crickets (Hadenoecus subterraneus) and (Ceuthophilus stygius) (Ceuthophilus latens), a Cave salamander (Eurycea lucifuga), two genera of Eyeless Cave Fish (Typhlichthys subterraneus) and (Amblyopsis spelaea), a Cave Crayfish (Orconectes pellucidus), and a Cave Shrimp (Palaemonias ganteri)

In addition, some surface animals may take refuge in the entrances of the caves but do not generally venture into the deep portions of the cavern system.

credited to wikipedia and flickr: Morland Smith, ontheopenroad, alanlee

White Sands

2009-04-02T09:39:00.000-07:00

The White Sands National Monument is a U.S. National Monument located about 25 km (15 miles) southwest of Alamogordo in western Otero County and northeastern Dona Ana County in the state of New Mexico, at an elevation of 4235 feet (1291 m). The area is in the mountain-ringed Tularosa Basin valley area and comprises the southern part of a 710-km² (275-mi²) field of white sand dunes composed of gypsum crystals.

History

The first exploration of the White Sands area by caucasian men was by a party of US Army officers in 1849. The Mescalero Apache were already living in the area at the time. Hispanic families started farming communities in the area at Tularosa in 1861 and at La Luz in 1863.

Description

Gypsum is rarely found in the form of sand because it is water-soluble. Normally, rain would dissolve the gypsum and carry it to the sea. Since the Tularosa Basin has no outlet to the sea, rain that dissolves gypsum from the surrounding San Andres and Sacramento Mountains is trapped within the basin, and the rain either sinks into the ground or forms shallow pools which subsequently dry out and leave gypsum in a crystalline form, called selenite, on the surface. During the last ice age, a lake known as Lake Otero covered much of the basin. When it dried out, it left a large flat area of selenite crystals which is now the Alkali Flat. Another lake, Lake Lucero, at the southwest corner of the park, is a dry lake bed, at one of the lowest points of the basin, which occasionally fills with water.

The ground in the Alkali Flat and along Lake Lucero's shore is covered with selenite crystals which reach lengths of up to three feet (1 m). Weathering and erosion eventually breaks the crystals into sand-size grains that are carried away by the prevailing winds from the southwest, forming white dunes. The dunes constantly change shape and slowly move downwind, covering the plants in their path. Some species of plants, however, can grow rapidly enough to avoid being buried by the dunes.

From the visitor center at the entrance of the park, the Dunes Drive leads 8 miles (12 km) into the dunes. Four marked trails allow to explore the dunes by foot. During the summer, there are also Ranger-guided orientation and nature walks. The park participates in the Junior Ranger Program, with various age-group-specific activities.

Unlike dunes made of quartz-based sand crystals, the gypsum does not readily convert the sun's energy into heat and thus can be walked upon safely with bare feet, even in the hottest summer months. In areas accessible by car, children frequently use the dunes for downhill sledding. Because the park lies completely within the White Sands Missile Range, both the park and U.S. Route 70 between Las Cruces, New Mexico and Alamogordo are subject to closure for safety reasons when tests are conducted on the missile range. On average, tests occur about twice a week, for a duration of one to two hours. Located on the northernmost boundaries of White Sands Missile Range, the Trinity Site can be found, where the first atom bomb was detonated.

credited to wikipedia

Death Valley

2009-03-31T07:27:00.000-07:00

Death Valley is a desert located in the southwestern United States. It is the lowest, driest, and hottest location in North America. Badwater, a basin located within Death Valley, is the specific location of the lowest elevation in North America at 85.5 m (282 ft) below sea level. This point is only 76 miles (123 km) east of Mount Whitney, the highest point in the contiguous United States. Death Valley holds the record for the highest reliably reported temperature in the Western hemisphere, 134°F (56.7°C) at Furnace Creek in 1913—just short of the world record, which was 136°F (58°C) in El Azizia, Libya, on September 13, 1922.

Located on the border between California and Nevada, southeast of the Sierra Nevada mountains in the Great Basin and the Mojave Desert, Death Valley constitutes much of Death Valley National Park and is the principal feature of the Mojave and Colorado Deserts Biosphere Reserve. It is located mostly in Inyo County, California. It runs from north to south between the Amargosa Range on the east and the Panamint Range on the west; the Sylvania Mountains and the Owlshead Mountains form its northern and southern boundaries, respectively. It has an area of about 3,000 square miles (~7,800 km²). Death Valley shares many characteristics with other places around the world that lie below sea level.

Geography

Geologically, Death Valley is considered one of the best examples of the basin and range configuration. It lies at the southern end of a geological trough known as Walker Lane, which runs north into Oregon. The valley is bisected by a right lateral strike slip fault system, represented by the Death Valley Fault and the Furnace Creek Fault. The eastern end of the left lateral Garlock Fault intersects the Death Valley Fault. Furnace Creek and the Amargosa River flow through the valley but eventually disappear into the sands of the valley floor.

Death Valley also contains salt pans. According to current geological consensus, during the middle of the Pleistocene era there was a succession of inland seas (collectively referred to as Lake Manly) located where Death Valley is today. As the area turned to desert the water evaporated, leaving behind the abundance of evaporitic salts such as common sodium salts and borax, which were subsequently exploited during the modern history of the region, primarily 1883 to 1907.

As a general rule, lower altitudes tend to have higher temperatures because the sun heats the ground and that heat is then radiated upward, but as the air begins to rise it is trapped by the surrounding elevation and the weight of the air (essentially the atmospheric pressure) above it. The atmospheric pressure is higher at very low altitudes than it is under the same conditions at sea level because there is more air (more distance) between the ground and the top of the atmosphere. This pressure traps the heat near the ground, and also creates wind currents that circulate very hot air, thereby distributing the heat to all areas, regardless of shade and other factors.

This process is especially important in Death Valley because of its specific climate and geography. Because the atmosphere is so dry and the ground is largely flat and unobstructed by plants, a high percentage of the sun's heat is able to reach the ground and be absorbed by the soil and rocks. When the hot air begins to rise it is trapped not only by atmospheric pressure and gently rising elevation, but also by high mountain ranges on all sides, and the hot wind currents are also trapped by the mountains so that they stay mostly within the valley. Death Valley holds temperature records because it has an unusually high number of factors that lead to high atmospheric temperatures.

Climate

Temperatures in the Valley can range from highs around 130°F (54°C) in the summer to lows below 32°F (0°C) in the winter. The National Climatic Data Center reports that temperatures at Furnace Creek reach at least 90°F (32°C) on an average of 189.3 days annually and at least 100°F (38°C) on an average of 138.0 days annually. The highest average temperature is in July at 117°F (47°C), with temperatures of 122°F (50°C) or higher being very common. The highest temperature ever recorded in the United States, according to National Weather Service records, was 134°F (56.7°C) at Furnace Creek (then known as Greenland Ranch) during a sandstorm on July 10, 1913. Freezing temperatures, on the other hand, occur an average of 11.7 days each year. The lowest temperature on record at Furnace Creek Inn is 15°F (-9°C), but nighttime temperatures in summer may only fall to 85°F to 95°F (30°C to 35°C).

Parts of the valley receive less than 2 in (50 mm) of rain annually. At Furnace Creek Inn, average annual precipitation is 2.33 inches and an average of 18.1 days per year have measurable precipitation. The greatest monthly precipitation on record was 2.59 inches in January 1995; the one-day record is 1.47 inch of precipitation, which fell on April 15, 1988. The average evaporation rate in the bottom of Death Valley is 150 inches per year. In the winter, precipitation approaching Death Valley is usually released onto the slopes to its west, causing a rain shadow. The four major mountain ranges to the west of Death Valley contribute to this effect.

Although Death Valley gets very little rain, it is prone to flooding during heavy rains because the soil is unable to absorb the water quickly. The runoff can produce dangerous flash floods. In August 2004, such flooding caused two deaths and caused the national park to close. On rare occasions, light snow has fallen on the valley floor. The most recent snow flurries at Furnace Creek Inn were on January 5, 1974.

credited to wikipedia and flickr: Bill Gracey, Walt K

De Chelly

2009-03-30T08:50:00.000-07:00

Canyon de Chelly National Monument was established April 1, 1931, as a unit of the National Park Service and is located in northeastern Arizona within the boundaries of the Navajo Nation. It preserves ruins of the early indigenous tribes that lived in the area, including the Ancient Pueblo Peoples (also called Anasazi) and Navajo. The monument covers 131 square miles (339 km2) and encompasses the floors and rims of the three major canyons: de Chelly, del Muerto, and Monument. These canyons were cut by streams with headwaters in the Chuska mountains just to the east of the monument.

Description

Canyon de Chelly is unique among National Park service units, as it consists entirely of Navajo Tribal Trust Land that remains home to the canyon community. Access to the canyon floor is restricted, and visitors are allowed to travel in the canyons only when accompanied by a park ranger or an authorized Navajo guide. The only exception to this rule is the White House Ruin Trail. Most park visitors arrive by automobile and view Canyon de Chelly from the rim, following both North Rim Drive and South Rim Drive. Ancient ruins and geologic structures are visible, but in the distance, from turnoffs on each of these routes. Tours of the canyon floor can be booked at the visitor center. There is no fee to see the canyon.

The National Monument was listed on the National Register of Historic Places on August 25, 1970.

A spectacular geologic feature is Spider Rock, a sandstone spire that rises 800 feet (240 m) from the canyon floor at the junction of Canyon de Chelly and Monument Canyon. Spider Rock can be seen from South Rim Drive. It has served as the scene of a number of television commercials.

According to traditional Navajo beliefs the taller of the two spires is the home of spider woman.

credited to wikipedia and flickr: acmelucky777

Bryce

2009-03-29T14:44:00.000-07:00

Bryce Canyon National Park is a national park located in southwestern Utah in the United States. Contained within the park is Bryce Canyon. Despite its name, this is not actually a canyon, but rather a giant natural amphitheater created by erosion along the eastern side of the Paunsaugunt Plateau. Bryce is distinctive due to its geological structures, called hoodoos, formed from wind, water, and ice erosion of the river and lakebed sedimentary rocks. The red, orange and white colors of the rocks provide spectacular views to visitors. Bryce is at a much higher elevation than nearby Zion National Park and the Grand Canyon. The rim at Bryce varies from 8,000 to 9,000 feet (2,400 to 2,700 m), whereas the south rim of the Grand Canyon sits at 7,000 feet (2,100 m) above sea level.

The Bryce area was settled by Mormon pioneers in the 1850s and was named after Ebenezer Bryce, who homesteaded in the area in 1874. The area around Bryce Canyon became a U.S. National Monument in 1923 and was designated as a national park the next year. The park covers 56 square miles (145 km2) and receives relatively few visitors compared to Zion Canyon and the Grand Canyon, largely due to its remote location. The town of Kanab, Utah, is situated at a central point between these three parks.

Geography

Bryce Canyon National Park is located in southern Utah about 50 miles (80 km) northeast of—and 1,000 feet (300 m) higher than—Zion National Park. The weather in Bryce Canyon is therefore cooler, and the park receives more precipitation: a total of 15 to 18 inches (38 to 46 cm) per year. Yearly temperatures vary from an average minimum of 9 °F (−13 °C) in January to an average maximum of 83 °F (28 °C) in July, but extreme temperatures can range from −30 °F to 97 °F (−34 °C to 36 °C).

The national park lies within the Colorado Plateau geographic province of North America and straddles the southeastern edge of the Paunsagunt Plateau west of the Paunsagunt Fault (Paunsagunt is Paiute for "home of the beaver"). Park visitors arrive from the plateau part of the park and look over the plateau's edge toward a valley containing the fault and the Paria River just beyond it (Paria is Paiute for "muddy or elk water"). The edge of the Kaiparowits Plateau bounds the opposite side of the valley.

Bryce Canyon was not formed from erosion initiated from a central stream, meaning it technically is not a canyon. Instead headward erosion has excavated large amphitheater-shaped features in the Cenozoic-aged rocks of the Paunsagunt Plateau. This erosion exposed delicate and colorful pinnacles called hoodoos that are up to 200 feet (61 m) high. A series of amphitheaters extends more than 20 miles (32 km) north-to-south within the park. The largest is Bryce Amphitheater, which is 12 miles (19 km) long, 3 miles (4.8 km) wide and 800 feet (240 m) deep. A nearby example of amphitheaters with hoodoos in the same formation but at a higher elevation, is in Cedar Breaks National Monument, which is 25 miles (40 km) to the west on the Markagunt Plateau.

Rainbow Point, the highest part of the park at 9,105 feet (2,775 m), is at the end of the 18-mile (29 km) scenic drive. From there, Aquarius Plateau, Bryce Amphitheater, the Henry Mountains, the Vermilion Cliffs and the White Cliffs can be seen. Yellow Creek, where it exits the park in the north-east section, is the lowest part of the park at 6,620 feet (2,020 m).

Geology

The Bryce Canyon area shows a record of deposition that spans from the last part of the Cretaceous period and the first half of the Cenozoic era. The ancient depositional environment of the region around what is now the park varied:

* The Dakota Sandstone and the Tropic Shale were deposited in the warm, shallow waters of the advancing and retreating Cretaceous Seaway (outcrops of these rocks are found just outside park borders).

* The colorful Claron Formation, from which the park's delicate hoodoos are carved, was laid down as sediments in a system of cool streams and lakes that existed from 63 to about 40 million years ago (from the Paleocene to the Eocene epochs). Different sediment types were laid down as the lakes deepened and became shallow and as the shoreline and river deltas migrated.

Several other formations were also created but were mostly eroded away following two major periods of uplift:

* The Laramide orogeny affected the entire western part of what would become North America starting about 70 million to 50 million years ago. This event helped to build the ancestral Rocky Mountains and in the process closed the Cretaceous Seaway. The Straight Cliffs, Wahweap, and Kaiparowits formations were victims of this uplift.

* The Colorado Plateaus were uplifted 16 million years ago and were segmented into different plateaus—each separated from its neighbors by faults and each having its own uplift rate. The Boat Mesa Conglomerate and the Sevier River Formation were removed by erosion following this uplift.

Vertical joints were created by this uplift, which were eventually (and still are) preferentially eroded. The easily-eroded Pink Cliffs of the Claron Formation responded by forming freestanding pinnacles in badlands called hoodoos, while the more resistant White Cliffs formed monoliths. The brown, pink and red colors are from hematite (iron oxide; Fe2O3); the yellows from limonite (Fe2O3•nH2); and the purples are from manganese oxide (MnO2). Also created were arches, natural bridges, walls, and windows. Hoodoos are composed of soft sedimentary rock and are topped by a piece of harder, less-easily-eroded stone that protects the column from the elements. Bryce Canyon has one of the highest concentrations of hoodoos of any place on Earth.

The formations exposed in the area of the park are part of the Grand Staircase. The oldest members of this supersequence of rock units are exposed in the Grand Canyon, the intermediate ones in Zion National Park, and its youngest parts are laid bare in Bryce Canyon area. A small amount of overlap occurs in and around each park.

Biology

More than 400 native plant species live in the park. There are three life zones in the park based on elevation:

* The lowest areas of the park are dominated by dwarf forests of pinyon pine and juniper with manzanita, serviceberry, and antelope bitterbrush in between. Aspen, Cottonwood, Water Birch, and Willow grow along streams.

* Ponderosa Pine forests cover the mid-elevations with Blue Spruce and Douglas-fir in water-rich areas and manzanita and bitterbrush as underbrush.

* Douglas-fir and White Fir, along with Aspen and Engelmann Spruce, make up the forests on the Paunsaugunt Plateau. The harshest areas have Limber Pine and ancient Great Basin Bristlecone Pine—some more than 1,600 years old—holding on.

The forests and meadows of Bryce Canyon provide the habitat to support diverse animal life, from birds and small mammals to foxes and occasional bobcats, mountain lions, and black bears. Mule deer are the most common large mammals in the park. Elk and pronghorn antelope, which have been reintroduced nearby, sometimes venture into the park.

Bryce Canyon National Park forms part of the habitat of three wildlife species that are listed under the Endangered Species Act: the Utah Prairie Dog, the California Condor, and the Southwestern Willow Flycatcher. The Utah Prairie Dog is a threatened species that was reintroduced to the park for conservation, and the largest protected population is found within the park's boundaries.

About 170 species of birds visit the park each year, including swifts and swallows. Most species migrate to warmer regions in winter, although jays, ravens, nuthatches, eagles, and owls stay. In winter, the mule deer, mountain lion, and coyotes migrate to lower elevations. Ground squirrels and marmots pass the winter in hibernation.

Eleven species of reptiles and four species of amphibians have been found at in the park. Reptiles include the Great Basin Rattlesnake, Short-horned Lizard, Side-blotched Lizard, Striped Whipsnake, and the Tiger Salamander.

Also in the park are the black, lumpy, very slow-growing colonies of cryptobiotic soil, which are a mix of lichens, algae, fungi, and cyanobacteria. Together these organisms slow erosion, add nitrogen to soil, and help it to retain moisture.

While humans have greatly reduced the amount of habitat that is available to wildlife in most parts of the United States, the relative scarcity of water in southern Utah restricts human development and helps account for the region's greatly enhanced diversity of wildlife.

credited to wikipedia

Crater Lake

2009-03-28T11:33:00.000-07:00

Crater Lake is a caldera lake located in the U.S. state of Oregon. It is the main feature of Crater Lake National Park and famous for its deep blue color and water clarity. The lake partly fills a nearly 4,000 foot (1,220 m) deep caldera that was formed around 5,677 (± 150) BC by the collapse of the volcano Mount Mazama.

On June 12, 1853, John Wesley Hillman was reportedly the first European American to see what he named "Deep Blue Lake" in Oregon. The lake was renamed at least three times, as Blue Lake, Lake Majesty, and finally Crater Lake.

Crater Lake is known for the "Old Man of the Lake", a full-sized tree that has been bobbing vertically in the lake for more than a century. Due to the cold water of the lake, the tree has been rather well preserved.

While having no indigenous fish population, the lake was stocked from 1888 to 1941 with a variety of fish. Several species have formed self sustaining populations.

The commemorative Oregon State Quarter, which was released by the United States Mint in 2005, features an image of Crater Lake on its reverse side.

Dimensions and depth

The lake is 5 by 6 miles (8 by 9.6 km) across with an average depth of 1,148 feet (350 m). Its deepest point has been measured at 1,949 feet (594 m) deep, though as with any lake its depth fluctuates with the climate, particularly rainfall. This makes Crater Lake the deepest lake in the United States, the second deepest lake in North America (Great Slave Lake is the deepest) and the ninth deepest lake in the world (Lake Baikal is the deepest). Crater Lake is often cited as the 7th deepest lake in the world, but this ranking excludes Lake Vostok, which is situated under nearly 13,000 feet (4000 m) of Antarctic ice, and the recent soundings of O'Higgins/San Martín Lake, which is located on the border of Chile and Argentina.

However, on the basis of comparing average depths among the world's deepest lakes, Crater Lake becomes the deepest lake in the Western Hemisphere and the third deepest in the world.[9] Comparing average depths among the world's lakes whose basins are entirely above sea level, Crater Lake is the deepest.[10]

The caldera rim of Crater Lake ranges in elevation from 7,000 to 8,000 feet (2,130 to 2,440 m).

Geology

Mount Mazama, part of the Cascade Range volcanic arc, was built up mostly of andesite, dacite, and rhyodacite over a period of at least 400,000 years. The caldera was created in a massive volcanic eruption that led to the subsidence of Mount Mazama around 5700 BC: about 50 cubic kilometers (12 cubic miles) of rhyodacite was erupted in this event. Since that time, all eruptions on Mazama have been confined to the caldera.

Lava eruptions later created a central platform, Wizard Island, Merriam Cone, and other, smaller volcanic features, including a rhyodacite dome that was eventually created atop the central platform. Sediments and landslide debris also covered the caldera floor.

Eventually, the caldera cooled, allowing rain and snow to accumulate and eventually form a lake. Landslides from the caldera rim thereafter formed debris fans and turbidite sediments on the lake bed. Fumaroles and hot springs remained common and active during this period. Also after some time, the slopes of the lake's caldera rim more or less stabilized, streams restored a radial drainage pattern on the mountain, and dense forests began to revegetate the barren landscape. It is estimated that about 720 years was required to fill the lake to its present depth of 594 m. Much of this occurred during a period when the prevailing climate was less moist than at present.

Some hydrothermal activity remains along the lake floor, suggesting that at some time in the future Mazama may erupt once again.

credited to wikipedia

Arches

2009-03-25T10:02:00.001-07:00

Arches National Park is a U.S. national park in eastern Utah. It is known for preserving over 2,000 natural sandstone arches, including the world-famous Delicate Arch, in addition to a variety of unique geological resources and formations.

The park is located near Moab, Utah, and is 119 square miles (310 km2) in size. Its highest elevation is 5,653 feet (1,723 m) at Elephant Butte, and its lowest elevation is 4,085 feet (1,245 m) at the visitor center. Since 1970, forty-three arches have toppled because of erosion. The park receives 10 inches (250 mm) of rain a year on average.

The area, administered by the National Park Service, was originally designated as a national monument on April 12, 1929. It was redesignated a national park on November 12, 1971. More than 833,000 people visited in 2006.

Features

Among the notable features of the park are:

* Delicate Arch — a lone-standing arch which has become a symbol of Utah

* Balanced Rock — a large balancing rock, the size of three school buses

* Double Arch — two arches that share a common end

* Landscape Arch — a very thin, very long arch over 300 feet (100 m); the largest in the park

* Fiery Furnace — an area of maze-like narrow passages and tall rock columns (see biblical reference Fiery Furnace)

* Devil's Garden — with many arches and columns scattered along a ridge

* Dark Angel — a free-standing column of dark stone at the end of the Devil's Garden trail

* Courthouse Towers — a collection of tall stone columns

* Petrified dunes — petrified remnants of sand dunes blown from the ancient lakes that covered the area.

* Wall Arch —located along the popular Devils Garden Trail. Collapsed sometime on August 4-5, 2008

Geology

The national park lies atop an underground salt bed, which is the main cause of the formation of the arches and spires, balanced rocks, sandstone fins, and eroded monoliths in the area. Thousands of feet thick in places, this salt bed was deposited over the Colorado Plateau some 300 million years ago when a sea flowed into the region and eventually evaporated. Over millions of years, the salt bed was covered with residue from floods and winds and the oceans that came in intervals. Much of this debris was compressed into rock. At one time this overlying earth may have been one mile (1.6 km) thick.

Salt under pressure is unstable, and the salt bed below Arches was no match for the weight of this thick cover of rock. Under such pressure it shifted, buckled, liquefied, and repositioned itself, thrusting the Earth layers upward into domes. Whole sections fell into cavities. In places they turned almost on edge. Faults occurred. The result of one such 2,500-foot (760 m) displacement, the Moab Fault, is seen from the visitor center.

As this subsurface movement of salt shaped the Earth, surface erosion stripped away the younger rock layers. Except for isolated remnants, the major formations visible in the park today are the salmon-colored Entrada Sandstone, in which most of the arches form, and the buff-colored Navajo Sandstone. These are visible in layer cake fashion throughout most of the park. Over time water seeped into the superficial cracks, joints, and folds of these layers. Ice formed in the fissures, expanding and putting pressure on surrounding rock, breaking off bits and pieces. Winds later cleaned out the loose particles. A series of free-standing fins remained. Wind and water attacked these fins until, in some, the cementing material gave way and chunks of rock tumbled out. Many damaged fins collapsed. Others, with the right degree of hardness and balance, survived despite their missing sections. These became the famous arches.

credited to wikipedia

Devils Tower

2009-03-24T09:31:00.000-07:00

Devils Tower (Lakota: Mato Tipila, which means “Bear Tower”) is a monolithic igneous intrusion or volcanic neck located in the Black Hills near Hulett and Sundance in Crook County, northeastern Wyoming, above the Belle Fourche River. It rises dramatically 386 m (1,267 ft) above the surrounding terrain and the summit is 1,558 m (5,112 ft) above sea level.

Devils Tower was the first declared United States National Monument, established on September 24, 1906, by President Theodore Roosevelt. The Monument's boundary encloses an area of 5.45 km² (1,347 acres).

In recent years about 1% of the Monument's 400,000 annual visitors climb Devils Tower, mostly through traditional climbing techniques.

Name

Tribes including the Arapaho, Crow, Cheyenne, Kiowa, Lakota, and Shoshone had cultural and geographical ties to the monolith before European and early American immigrants reached Wyoming. Their names for the monolith include: Aloft on a Rock (Kiowa), Bear's House (Cheyenne, Crow), Bear's Lair (Cheyenne, Crow), Bear's Lodge (Cheyenne, Lakota), Bear's Lodge Butte (Lakota), Bear's Tipi (Arapaho, Cheyenne), Tree Rock (Kiowa), and Grizzly Bear Lodge (Lakota).

The name Devil's Tower originated in 1875 during an expedition led by Col. Richard Irving Dodge when his interpreter misinterpreted the name to mean Bad God's Tower. This was later shortened to the Devil's Tower. All information signs in that area use the name "Devils Tower", following a geographic naming standard whereby the apostrophe is eliminated.

In 2005, a proposal to recognize the American Indian ties through the additional designation of the monolith as Bear Lodge National Historic Landmark met with opposition from the US Representative Barbara Cubin, arguing that a "name change will harm the tourist trade and bring economic hardship to area communities".

Geological history

Most of the landscape surrounding Devils Tower is composed of sedimentary rocks.

The oldest rocks visible in Devils Tower National Monument were laid down in a shallow sea during the Triassic period, 225 to 195 million years ago. This dark red sandstone and maroon siltstone, interbedded with shale, can be seen along the Belle Fourche River. Oxidation of iron minerals causes the redness of the rocks. This rock layer is known as the Spearfish formation.

Above the Spearfish formation is a thin band of white gypsum, called the Gypsum Spring Formation. This layer of gypsum was deposited during the Jurassic period, 195 to 136 million years ago.

Created as sea levels and climates repeatedly changed, gray-green shales (deposited in low-oxygen environments such as marshes) were interbedded with fine-grained sandstones, limestones, and sometimes thin beds of red mudstone. This composition, called the Stockade Beaver member, is part of the Sundance Formation. The Hulett Sandstone member, also part of the Sundance formation, is composed of yellow fine-grained sandstone. Resistant to weathering, it forms the nearly vertical cliffs which encircle the Tower itself.

About 65 million years ago, during the Tertiary period, the Rocky Mountains and the Black Hills were uplifted. Molten magma rose through the crust, intruding into the already existing sedimentary rock layers.

credited towikipedia and flickr: twomets, champy1013, clare&joe

Yosemite

2009-03-23T11:04:00.000-07:00

Yosemite National Park is a national park located in the eastern portions of Tuolumne, Mariposa and Madera counties in east central California, United States. The park covers an area of 761,266 acres or 1,189 square miles (3,081 km²) and reaches across the western slopes of the Sierra Nevada mountain chain. Yosemite is visited by over 3.5 million people each year, many of whom only spend time in the seven square miles (18 km²) of Yosemite Valley. Designated a World Heritage Site in 1984, Yosemite is internationally recognized for its spectacular granite cliffs, waterfalls, clear streams, Giant Sequoia groves, and biological diversity. Almost 95% of the park is designated wilderness. Although not the first designated national park, Yosemite was a focal point in the development of the national park idea, largely owing to the work of people like John Muir and Galen Clark.

Yosemite is one of the largest and least fragmented habitat blocks in the Sierra Nevada, and the park supports a diversity of plants and animals. The park has an elevation range from 2,000 to 13,114 feet (600 to 4,000 m) and contains five major vegetation zones: chaparral/oak woodland, lower montane, upper montane, subalpine, and alpine. Of California's 7,000 plant species, about 50% occur in the Sierra Nevada and more than 20% within Yosemite. There is suitable habitat or documentation for more than 160 rare plants in the park, with rare local geologic formations and unique soils characterizing the restricted ranges many of these plants occupy.

The geology of the Yosemite area is characterized by granitic rocks and remnants of older rock. About 10 million years ago, the Sierra Nevada was uplifted and then tilted to form its relatively gentle western slopes and the more dramatic eastern slopes. The uplift increased the steepness of stream and river beds, resulting in formation of deep, narrow canyons. About 1 million years ago, snow and ice accumulated, forming glaciers at the higher alpine meadows that moved down the river valleys. Ice thickness in Yosemite Valley may have reached 4,000 feet (1200 m) during the early glacial episode. The downslope movement of the ice masses cut and sculpted the U-shaped valley that attracts so many visitors to its scenic vistas today.

Geography

Yosemite National Park is located in the central Sierra Nevada of California. It takes approximately 3.5 hours to drive to the park from San Francisco and approximately 6 hours from Los Angeles. Yosemite is surrounded by wilderness areas: the Ansel Adams Wilderness to the southeast, the Hoover Wilderness to the northeast, and the Emigrant Wilderness to the north.

The 1,189 sq mi (3,081 km²) park is roughly the size of Rhode Island and contains thousands of lakes and ponds, 1,600 miles (2,600 km) of streams, 800 miles (1300 km) of hiking trails, and 350 miles (560 km) of roads. Two federally designated Wild and Scenic Rivers, the Merced and the Tuolumne, begin within Yosemite's borders and flow westward through the Sierra foothills, into the Central Valley of California. Annual park visitation exceeds 3.5 million, with most visitor use concentrated in the seven square mile (18 km²) area of Yosemite Valley.

Rocks and erosion

Almost all of the landforms in the Yosemite area are cut from the granitic rock of the Sierra Nevada Batholith (a batholith is a large mass of intrusive igneous rock that formed deep below the surface). About 5% of the park (mostly in its eastern margin near Mount Dana) are from metamorphosed volcanic and sedimentary rocks. These rocks are called roof pendants because they were once the roof of the underlying granitic rock.

Erosion acting upon different types of uplift-created joint and fracture systems is responsible for creating the valleys, canyons, domes, and other features we see today. These joints and fracture systems do not move, and are therefore not faults. Spacing between joints is controlled by the amount of silica in the granite and granodiorite rocks; more silica tends to create a more resistant rock, resulting in larger spaces between joints and fractures.

Pillars and columns, such as Washington Column and Lost Arrow, are created by cross joints. Erosion acting on master joints is responsible for creating valleys and later canyons. The single most erosive force over the last few million years has been large alpine glaciers, which have turned the previously V-shaped river-cut valleys into U-shaped glacial-cut canyons. Exfoliation (caused by the tendency of crystals in plutonic rocks to expand at the surface) acting on granitic rock with widely spaced joints is responsible for creating domes such as Half Dome and North Dome and inset arches like Royal Arches.

Popular features

Yosemite Valley represents only one percent of the park area, but this is where most visitors arrive and stay. El Capitan, a prominent granite cliff that looms over the valley, is one of the most popular rock climbing destinations in the world because of its diverse range of climbing routes in addition to its year-round accessibility. Granite domes such as Sentinel Rock and Half Dome rise 3,000 feet and 4,800 feet (900 and 1,450 m), respectively, above the valley floor.

The high country of Yosemite contains beautiful areas such as Tuolumne Meadows, Dana Meadows, the Clark Range, the Cathedral Range, and the Kuna Crest. The Sierra crest and the Pacific Crest Trail run through Yosemite, with peaks of red metamorphic rock, such as Mount Dana and Mount Gibbs, and granite peaks, such as Mount Conness. Mount Lyell is the highest point in the park.

The park has three groves of ancient Giant Sequoia trees; the Mariposa Grove (200 trees), the Tuolumne Grove (25 trees), and the Merced Grove (20 trees). This species grows larger in volume than any other and is one of the tallest and longest-lived. These trees were much more widespread before the start of the last Ice Age.

Water and ice

Tuolumne and Merced River systems originate along the crest of the Sierra Nevada in the park and have carved river canyons 3,000 to 4,000 feet (900 to 1,200 m) deep. The Tuolumne River drains the entire northern portion of the park, an area of approximately 680 square miles (1,760 km²). The Merced River begins in the park's southern peaks, primarily the Cathedral and Clark Ranges, and drains an area of approximately 511 square miles (1,320 km²).

Hydrologic processes, including glaciation, flooding, and fluvial geomorphic response, have been fundamental in creating landforms in the park. The park also contains approximately 3,200 lakes (greater than 100 m²), two reservoirs, and 1,700 miles (2,700 km) of streams, all of which help form these two large watersheds. Wetlands in Yosemite occur in valley bottoms throughout the park, and are often hydrologically linked to nearby lakes and rivers through seasonal flooding and groundwater movement. Meadow habitats, distributed at elevations from 3,000 to 11,000 feet (900 to 3,500 m) in the park, are generally wetlands, as are the riparian habitats found on the banks of Yosemite's numerous streams and rivers.

Yosemite is famous for its high concentration of waterfalls in a small area. Numerous sheer drops, glacial steps and hanging valleys in the park provide many places for waterfalls to exist, especially during April, May, and June (the snowmelt season). Located in Yosemite Valley, the 2,425-foot-high (739 m) Yosemite Falls is the highest in North America. Also in the valley is the much lower volume Ribbon Falls, which has the highest single vertical drop, 1,612 feet (492 m). Perhaps the most prominent of the Yosemite waterfalls is Bridalveil Fall, which is the waterfall seen from the Tunnel View viewpoint at the east end of the Wawona Tunnel. Wapama Falls in Hetch Hetchy Valley is another notable waterfall. Hundreds of ephemeral waterfalls also exist in the park.

All glaciers in the park are relatively small glaciers that occupy areas that are in almost permanent shade, such as north- and northeast-facing cirques. Lyell Glacier is the largest glacier in the Sierra Nevada (and therefore the park) and covers 160 acres (65 ha). None of the Yosemite glaciers are a remnant of the much, much larger Ice Age alpine glaciers responsible for sculpting the Yosemite landscape. Instead, they were formed during one of the neoglacial episodes that have occurred since the thawing of the Ice Age (such as the Little Ice Age). Global warming has reduced the number and size of glaciers around the world. Many Yosemite glaciers, including Merced Glacier, which was discovered by John Muir in 1871 and bolstered his glacial origins theory of the Yosemite area, have disappeared and most of the others have lost up to 75% of their surface area.

Climate

Yosemite has a Mediterranean climate, meaning most precipitation falls during the mild winter, and the other seasons are nearly dry (less than 3% of precipitation falls during the long, hot summers). Due to orographic lift, precipitation increases with elevation up to 8,000 feet (2,400 m) where it slowly decreases to the crest. Precipitation amounts vary from 36 inches (915 mm) at 4,000 feet (1,200 m) elevation to 50 inches (1,200 mm) at 8,600 feet (2,600 m). Snow does not typically persist on the ground until November in the high country. It accumulates all winter and into March or early April.

Temperature decreases with increasing elevation. Temperature extremes are moderated by the fact that Yosemite is only about 100 miles (160 km) from the Pacific Ocean. An anticyclone sits off the coast of California in the summer, sending cool air masses toward the Sierra Nevada that result in clean dry air in the Yosemite area.

Mean daily temperatures range from 25 to 53 °F (-3.9 to 11.5 °C) at Tuolumne Meadows at 8,600 feet (2,600 m). At the Wawona Entrance (elevation 5,130 feet; 1,564 m), mean daily temperature ranges from 36 to 67 °F (2.2 to 19.4 °C). At the lower elevations below 5,000 feet (1525 m), temperatures are hotter; the mean daily high temperature at Yosemite Valley (elevation 3,966 feet; 1,209 m) varies from 46 to 90 °F (7.8 to 32.2 °C). At elevations above 8,000 feet (2,440 m), the hot, dry summer temperatures are moderated by frequent summer thunderstorms, along with snow that can persist into July. The combination of dry vegetation, low relative humidity, and thunderstorms results in frequent lightning-caused fires as well.

At the park headquarters, normal January temperatures range from 47.2°F to 25.6°F and normal July temperatures range from 89.9°F to 53.2°F. There are an average of 47.7 days with highs of 90°F (32°C) or higher and an average of 137.5 days with lows of 32°F (0°C) or lower. Freezing temperatures have been recorded in every month of the year. The record high temperature was 115°F on July 20, 1915. The record low temperature was -6°F on January 2, 1924. Average annual precipitation is 36.57 inches; there an average of 69 days with measurable precipitation. The wettest year was 1983 with 68.94 inches and the dryest year was 1976 with 14.84 inches. The most precipitation in one month was 29.61 inches in December 1955 and the most in one day was 6.92 inches on December 23, 1955. Average annual snowfall is 65.6 inches. The snowiest year was 1967 with 154.9 inches. The most snow in one month was 140.8 inches in January 1993.

credited to wikipedia and flickr: Buck Forester

Badlands

2009-03-21T09:59:00.000-07:00

A badlands (also badland) is a type of arid terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded by wind and water. It can resemble malpaís, a terrain of volcanic rocks. Canyons, ravines, gullies, hoodoos and other such geological forms are common in badlands. They are often difficult to navigate by foot. Badlands often have a spectacular colour display that alternates from dark black/blue coal stria to bright clays to red scoria.

Features

The term "badlands" represents a consensus in North America: the Lakota called the topography "Makhóšiča", literally bad land, while French trappers called it "les mauvaises terres à traverser" – "the bad lands to cross". The Spanish called it tierra baldía ("waste land") and cárcava. The term badlands is also apt: badlands contain steep slopes, loose dry soil, slick clay, and deep sand, all of which impede travel and other uses. Badlands form in arid regions with infrequent but intense rain-showers, sparse vegetation, and soft sediments: a recipe for massive erosion.

Some of the most famous fossil beds are found in badlands, where erosion rapidly exposes the sedimentary layers and the scant cover of vegetation makes surveying and fossil hunting relatively easy.

Coal seams are also exposed in some badlands, so historically, coal mining districts have developed in badlands areas. An example of this is the Drumheller district of the Red Deer River in Alberta, where the Atlas Coal Mine is the last of 149 mines that operated in those badlands.

Locations

Some of the best-known badland formations can be found in the United States and Canada. In the U.S., Makoshika State Park in Montana, Theodore Roosevelt National Park in North Dakota and Badlands National Park in South Dakota together form a series of extensive badlands formations. Another popular area of badland formations is Toadstool Geologic Park in the Oglala National Grassland of northwestern Nebraska. The Big Muddy Badlands in Saskatchewan, Canada gained notoriety as a hideout for outlaws. There is a sizable badland area in Alberta, Canada, particularly in the valley of the Red Deer River where Dinosaur Provincial Park is located. The Royal Tyrrell Museum of Palaeontology in Drumheller, Alberta and Dinosaur National Monument in Utah are also badlands settings, and exhibit fossils found in the area. A small badlands called Hell's Half-Acre is present in Natrona County, Wyoming. It is famous as one of the locations for the filming of Starship Troopers (1997).

Arguably the most well known badlands formation in New Zealand, the Putangirua Pinnacles – formed by the erosion of the conglomerate of an old alluvial fan – are located at the head of a small valley near the southern tip of the North island. A famous European badland is the Bardenas Reales near Tudela, Spain.

Although most badland scenery is natural, there are some spectacular examples produced by mining, such as the Roman gold mine of Las Médulas in northern Spain.

credited to wikipedia

Western Brook

2009-03-20T08:04:00.000-07:00

The Western Brook Pond is a Canadian fjord or lake located in Gros Morne National Park on the west coast of the island of Newfoundland. It is in the Long Range Mountains, the most northern section of the Appalachian Mountains.

It is surrounded by steep rock walls 600 m (2,000 ft) high., having been carved from the surrounding plateau by glaciers. After the glaciers melted, the land rebounded and the fjord was cut off from the sea. Salty water was eventually flushed from the fjord leaving it fresh. The catchment area is composed of igneous rock with relatively thin soil, so the waters feeding Western Brook Pond are low in nutrients and the lake is classified as ultraoligotrophic. It is fed by Stag Brook at the extreme eastern end of the lake and by numerous waterfalls cascading from the plateau above. One of these, Pissing Mare Falls at 350 m (1,100 ft), is one of the highest in eastern North America.

The lake is accessible by a moderate-easy 3 km (1.9 mi) hiking trail over coastal bogs and low limestone ridges. Two tour boats, one with a capacity of 70 passengers and the other 90 passengers, cruise the lake from June to mid-October. The lake waters are pristine, having had very little impact from human activities. The tour boat operators had to undergo special certification to ensure that their operations would have minimal impact on the environment.

In the early part of the 20th century, a part of the surrounding cliff broke off and fell into the lake, causing a 30 m (98 ft) tsunami.

credited to wikipedia and flickr: tmod, Product of Newfoundland, JamieK2007

Nahanni

2009-03-19T09:44:00.000-07:00

The South Nahanni River is the centrepiece of Nahanni National Park Reserve, located roughly 500 kilometres west of Yellowknife in the Northwest Territories of Canada. It flows from the western slopes of Mount Christie in the west, through the Selwyn Mountains, growing as it heads east over the majestic Virginia Falls, and finally empties into the Liard River. The Nahanni has a unique geological history. It was formed when the area was a broad flat plain, forming a winding course typical of flatland rivers. As the mountains lifted, the river cut four deep canyons into the rock, maintaining its eccentric course.

The Dene and their ancestors have lived and hunted in the Nahanni area for thousands of years. In the early 19th century, the first Europeans came to the area, seeking fur and gold; however, it wasn't until the 1950s, with the publishing of Dangerous River by R.M. Patterson that the legends about the region were put to rest and the river finally came to prominence. Since that time, the Nahanni has become one of the prime wilderness rivers in Canada, frequented as a whitewater destination by adventure seekers around the world.

Course

The headwaters of the South Nahanni River originate on the western slopes of Mount Christie of the Mackenzie Mountains, at an elevation of 1600m. It flows south on the Yukon/Northwest Territories border for 10 km, then turns south-east into the Northwest Territories at the Moose Ponds. It flows through the Selwyn Mountains, where it receives the waters of the Little Nahanni River, south of the Sapper Range. East of the Bologna Ridge it turns west, then again south-east. It receives the waters of the Broken Skull River east of the Vampire Peaks Range, then the waters of the Rabittkettle River and Hole in the Wall Creek as it enters the Nahanni National Park Reserve. The river crosses the entire length of the park reserve, and the confluence with the Flat River is also located here. At the eastern limit of the national park it passes between the Liard Range and the Twisted Mountain, where it receives the Jackfish River, then continues in a meandered flow and empties into the Liard River at Nahanni Butte, 90 km north of Fort Liard, at an elevation of 180 m. Note: The South Nahanni River has recently been proven to run 563km.

Geography

The history of the area began 550 million years ago beneath a tropical sea. Here a sedimentary layer of sandstone and limestone formed from the powerful pressure exerted by the sea. Eventually this sea dried up, forming a wide plain upon which the Nahanni River first took its course.

The Nahanni is unique amongst mountainous rivers. It formed long before the mountains ever existed, establishing a winding course typical of prairie rivers. As the mountains rose around it, the Nahanni maintained its course, cutting steep canyons into the land.

The river runs through several distinct ranges of mountains, all part of the Mackenzie Range. At its head waters, it runs through the much more rugged Selwyn Mountains, formed from the colliding North American and Pacific Plates roughly 200 million years ago. As the river travels east, it transitions into a gentler terrain of rolling sedimentary mountains formed around the same time by batholiths pushing the sedimentary layers upward, and forming large granite intusions. Finally, the Nahanni empties into the plains of the Liard River, unaffected by the powerful forces nearby.

During the last glaciation two ice sheets advanced along the Nahanni. The Cordilleran advanced from the west, and the Laurentide from the east. The middle portions of the river managed to escape glaciation entirely, and so feature some of the oldest undisturbed landscape in Canada.

Although it escaped the powerful scouring effects of the glaciars, the middle section of the river was not entirely unaffected. The Laurentide Ice Sheet blocked off the mouth of the river, and so the river valley filled up, twice forming the large glacial lake Nahanni, and once forming the smaller Glacial Lake Tetcella. This had a profound effect on the river's most famous feature, Virginia Falls.

The current course of the Nahanni River around Virginia Falls was originally blocked by a spur of the nearby Sunblood Mountain. Sometime during the Illinoian Stage (352,000 to 132,000 years ago), a glacier severed the spur, and the river took its present course, cutting into the land and forming the Fourth Canyon. During the last glaciation, the valley was immersed by Glacial Lake Nahanni, and heavy silting from the glacial water filled in the course once again, shifting the falls to their present location.

Further downstream, the First, Second, and Third Canyons were also unaffected by the direct power of glaciation. The canyons of the Nahanni River are somewhat unique as a result. Usually when a river erodes the land, forming a valley, the valley takes the form of a V shape. The effect of glaciers on these V-shaped valleys is unmistakable, leaving a steeper U-shaped valley. Because the Nahanni's course was already established before the mountains rose, it formed steep canyon wall that plummet hundreds of feet to the river's edge. Relatively untouched by glaciation, these canyon's continue on in their ancient state.

credited to wikipedia and flickr: gshollings@rogers.com

Katmai

2009-03-17T11:20:00.000-07:00

Mount Katmai is a large stratovolcano (composite volcano) on the Alaska Peninsula in southern Alaska, located within Katmai National Park and Preserve. It is about 6 miles (10 km) in diameter with a central lake-filled caldera about 3 by 2 mi (4.5 by 3 km) in area, formed during the Novarupta eruption of 1912. The caldera rim reaches a maximum elevation of 6,716 feet (2,047 m). In 1975 the surface of the crater lake was at an elevation of about 4,220 feet (1,286 m), and the estimated elevation of the caldera floor is about 3,400 ft (1,040 m). The mountain is divided between Kodiak Island Borough on its southeast and Lake and Peninsula Borough on its northwest.

Geology

Mount Katmai is one of five vents encircling the Novarupta dome, source of the VEI 6 eruption and associated voluminous pyroclastic flows in 1912. The volcano has caused ten known fatalities due to gas exposure. Katmai consists chiefly of lava flows, pyroclastic rocks, and non-welded to agglutinated air fall. The Quaternary volcanic rocks at Katmai and adjacent cones are less than 5,000 ft (1,500 m) thick. Much of the volcano is mantled by snow and ice and several valley glaciers radiate out from the flanks and three glaciers.

Katmai volcano is built on the sedimentary rocks of the Naknek Formation of Late Jurassic age, which are exposed just west of the caldera rim at an elevation of about 5,000 feet (1,520 m), as well as north and southeast of the crater. Sedimentary rocks have been reported at an elevation of over 6,000 feet (1,830 m) in the west wall of the caldera and near the bottom of the eastern wall near 3,400 ft (1,040 m).

Volcanic activity

Little is known about the historical activity of Katmai volcano before the great 1912 eruption. Early U.S. Coast and Geodetic Survey maps suggest a pre-caldera summit elevation of about 7,500 ft (2,300 m), and local villagers reported in 1898 that one of the volcanoes in the general area "smoked" occasionally.

On June 6-9th, 1912, the most spectacular Alaskan eruption in recorded history and one of the two largest eruptions in the world in the twentieth century (the other being Mount Pinatubo in 1991) resulted in the formation of a large summit caldera at Katmai volcano. The over 60-hour-long eruption actually took place at a vent about 6 mi (10 km) to the west of Mount Katmai (now marked by Novarupta dome) from which an estimated 30-35 km³ of ash flows and tephra were ejected rather than at Mount Katmai itself. Based on geochemical and structural relationships, it has been suggested that magma drained from beneath Katmai Volcano to Novarupta via the plumbing system beneath Trident Volcano. The withdrawal of magma beneath Katmai resulted in the collapse of the summit area, forming the caldera. Following the subsidence, a small dacitic cinder cone was emplaced on the floor of the caldera; this is the only juvenile material erupted from Katmai caldera during the historical eruption.

Approximately 12-15 km³ of magma was vented during the 1912 eruption producing about 35 km³ of tephra. An estimated 11-15 km³ of ash flow tuff traveled 12 miles (20 km) northwest covering an area of about 120 km² in what subsequently came to be known as the Valley of Ten Thousand Smokes. The ash flow tuff produced in the 1912 eruption is made up of a silica-rich volcanic rock called rhyolite. In fact, this is the only major Quaternary eruption of rhyolite to have occurred in Alaska. Maximum thickness of the ashflow is estimated to be about 800 feet (240 m). About 20 km³ of airfall tephra was carried east and southeast with a minor lobe to the north covering 77,000 km² with more than 1 in (2.5 cm) of ash. Light ash fall was reported as far away as the Puget Sound region 1,500 mi (2,400 km) away. Extremely fine ash blown into the stratosphere remained in suspension as aerosols for months and caused spectacular red sunsets in many parts of the world.

In 1919, geologists noted a lake covering a large part of the caldera floor, but by 1923 the lake was gone and numerous fumaroles, mud pots, and a large mud geyser had replaced it. The lake has since refilled to a depth of over 800 ft (240 m). Small glaciers have also formed on a bench within the caldera beside the lake.

credited to wikipedia and avo.alaska

Brooks Range

2009-03-16T13:11:00.000-07:00

The Brooks Range is a mountain range that stretches from west to east across northern Alaska and into Canada's Yukon Territory, a total distance of about 1100 km (700 mi). The mountains top out at over 2,700 m (9,000 ft). Mount Chamberlin, 9020 ft (2,749 m), is the highest peak in the range. Other notable peaks include Mount Isto, 8,975 ft (2,736 m) and Mount Michelson, 8,855 ft (2,699 m).

The range is mostly uninhabited, but the Dalton Highway and the Trans-Alaska Pipeline System run through the Atigun Pass (1,415 m, 4,643 ft) on their way to the North Slope and the oil fields at Prudhoe Bay. The Alaska Native villages of Anaktuvuk and Arctic Village, as well as the very small communities of Coldfoot, Wiseman, Bettles, and Chandalar Lake are the only settlements in the 700-mile Brooks Range. In the far west, near the Wulik River in the De Long Mountains is the Red Dog Mine, Alaska, largest zinc mine in the world.

The range was named by the United States Board on Geographic Names in 1925 after Alfred Hulse Brooks, who was the chief USGS geologist for Alaska from 1903 to 1924.

Various historical records also referred to the range as the Arctic Mountains, Hooper Mountains, Meade Mountains and Meade River Mountains; the Canadian portion is still often referred to as the British Mountains. The British Mountains are part of Ivvavik National Park.

Ecology

This mountain range forms the northern-most drainage divide in North America, separating streams flowing into the Arctic Ocean and the North Pacific. The range roughly delineates the summer position of the Arctic front. It represents the northern extent of tree line, with few trees occurring north of the continental drainage divide. The southern slopes of the Brooks Range have some cover of Black Spruce, Picea mariana, marking the northern limit of that tree. As one of the most remote and least-disturbed wildernesses of North America, the mountains are teeming with wildlife, including Dall sheep, grizzly bears, and caribou.

credited to wikipedia and flickr: backpackphotography, johnjan99ca, jcoutside

Glacier Bay

2009-03-12T13:51:00.000-07:00

Glacier Bay is a bay in south-eastern Alaska, United States. It runs north northwest to south south-east for about 105 km (65 miles) between two pinchets of Alaska. It ranges from 5-30 km (3-20 miles) wide. Glacier Bay and the surrounding land is the site of the Glacier Bay National Park and Preserve. The area is a popular cruise ship destination, with several ships leaving Seattle each week during the summer with Glacier Bay as the end destination.

The explorer Captain George Vancouver found Icy Strait, at the south end of Glacier Bay, choked with ice in 1794. Glacier Bay itself was almost entirely iced over. In 1879 naturalist John Muir found that the ice had retreated almost all the way up the bay. By 1916 Grand Pacific Glacier was at the head of Tarr Inlet, about 100 km (65 miles) from Glacier Bay's mouth. This is the fastest documented glacial retreat ever. Scientists are hoping to learn how glacial activity relates to climate changes from the retreat.

Plants progressively moved in as the glacier retreated, so a 200-year-old spruce and hemlock forest presently exists at the entrance, grading up to more primitive plants such as mosses and lichens at the head of the bay. Because of current local climate change due to global warming, some glaciers are now retreating at a rate of up to a quarter of a mile per year.

Glacier Bay contains sixteen glaciers, twelve of which reach shorelines and calve (shed broken pieces of ice) to produce icebergs.

credited to wikipedia and flickr: hfpierson, Anita Gould, nclint1617

Ellesmere

2009-03-11T15:58:00.000-07:00

Ellesmere Island is part of the Qikiqtaaluk Region of the Canadian territory of Nunavut. Lying within the Canadian Arctic Archipelago it is considered part of the Queen Elizabeth Islands, with Cape Columbia being the most northerly point of land in Canada. It comprises an area of 196,235 km2 (75,767 sq mi), making it the world's tenth largest island and Canada's third largest island. The Arctic Cordillera mountain system covers much of Ellesmere Island, making it the most mountainous in the Canadian Arctic Archipelago. The Arctic willow is the only woody species to grow on Ellesmere Island.

History

The first inhabitants of Ellesmere Island were small bands drawn to the area for Peary caribou, muskox, and marine mammal hunting about 2000–1000 BC.

As was the case for the Dorset (or Palaeoeskimo) hunters and the pioneering Neoeskimos, the Post-Ruin Island and Late Thule culture Inuit used the Bache Peninsula region extensively both summer and winter until environmental, ecological and possibly social circumstances caused the area to be abandoned. It was the last region in the Canadian High Arctic to be depopulated during the "Little Ice Age", attesting to its general economic importance as part of the Smith Sound culture sphere of which it was occasionally a part and sometimes the principal settlement component.

Vikings from the Greenland colonies reached Ellesmere Island, Skraeling Island and Ruin Island during hunting expeditions and trading with the Inuit groups. Unusual structures on Bache peninsula may be the remains of a late-period Dorset stone longhouse.

The first European to sight the island after the height of the "Little Ice Age" was William Baffin, in 1616; said "Age" lasted until roughly 1850. Ellesmere Island was named in 1852 by Edward Inglefield's expedition after Francis Egerton, 1st Earl of Ellesmere. The American expedition led by Adolphus Greely in 1881 crossed the island from east to west. The Greely expedition found fossil forests on Ellesmere Island in the late 1880s. Stenkul Fiord was first explored in 1902 by Per Schei, a member of Otto Sverdrup's 2nd Norwegian Polar Expedition.

The Ellesmere Ice Shelf was documented by the British Arctic Expedition of 1875–76, in which Lieutenant Pelham Aldrich's party went from Cape Sheridan west to Cape Alert, including the Ward Hunt Ice Shelf. In 1906 Robert Peary led an expedition in northern Ellesmere Island, from Cape Sheridan along the coast to the western side of Nansen Sound . During Peary's expedition, the Ice Shelf was continuous; a modern estimate is that it covered 8,900 km2 (3,400 sq mi).

Geography

Protected areas

More than one-fifth of the island is protected as Quttinirpaaq National Park (formerly Ellesmere Island National Park Reserve), which includes seven fjords and a variety of glaciers, as well as Lake Hazen, North America's largest lake north of the Arctic Circle. Barbeau Peak, the highest mountain in Nunavut (2,616 m (8,580 ft)) is located in the British Empire Range on Ellesmere Island. The most northern mountain range in the world, the Challenger Mountains, is located in the northeast region of the island. The northern lobe of the island is called Grant Land.

In July 2007, a study noted the disappearance of habitat for waterfowl, invertebrates, and algae on Ellesmere Island. According to John P. Smol of Queen's University in Kingston, Ontario, and Marianne S. V. Douglas of the University of Alberta in Edmonton, warming conditions and evaporation have caused low water levels changes in the chemistry of ponds and wetlands in the area. The researchers noted that "In the 1980s they often needed to wear hip waders to make their way to the ponds...while by 2006 the same areas were dry enough to burn.

Glaciers and ice caps

Large portions of Ellesmere Island are covered with glaciers and ice, with Manson Icefield and Sydkap in the south; Prince of Wales Icefield and Agassiz Ice Cap along the central-east side of the island, along with substantial ice cover in Northern Ellesmere Island. The northwest coast of Ellesmere Island was covered by a massive, 500 km (310 mi) long ice shelf until the 20th century. The Ellesmere Ice Shelf was reduced by 90 percent in the twentieth century due to global warming, leaving the separate Alfred Ernest, Ayles, Milne, Ward Hunt, and Markham Ice Shelves. A 1986 survey of Canadian ice shelves found that 48 km2 (19 sq mi) 3.3 km3 (0.79 cu mi) of ice calved from the Milne and Ayles ice shelves between 1959 and 1974. The Ward Hunt Ice Shelf, the largest remaining section of thick (>10 m, >30 ft) landfast sea ice along the northern coastline of Ellesmere Island, lost 600 km (370 mi) of ice in a massive calving in 1961-1962. It further decreased by 27% in thickness (13 m (43 ft)) between 1967 and 1999.

The breakup of the Ellesmere Ice Shelves has continued in the 21st century: the Ward Ice Shelf experienced a major breakup during summer 2002; the Ayles Ice Shelf calved entirely on August 13, 2005; the largest breakoff of the ice shelf in 25 years, it may pose a threat to the oil industry in the Beaufort Sea. The piece is 66 km2 (25 sq mi). In April 2008, it was discovered that the Ward Hunt shelf was fractured into dozens of deep, multi-faceted cracks and in September 2008 the Markham shelf (50 sq km / 20 square miles) completely broke off to become floating sea-ice.

Paleontology

Schei and later Nathorst described the Paleocene-Eocene (ca. 55 Ma) fossil forest in the Stenkul Fiord sediments. The Stenkul Fiord site represents a series of deltaic swamp and floodplain forests. The trees stood for at least 400 years. Individual stumps and stems of >1 m (>3 ft) diameter were abundant. Abundance of Metasequoia and possibly Glyptostrobus trees.

In 2006, University of Chicago paleontologist Neil H. Shubin reported the discovery of the fossil of a Paleozoic (ca. 375 Ma) fish, named Tiktaalik roseae, in the former stream beds of Ellesmere Island. The fossil exhibits many characteristics of fish, but also indicates a transitional creature that may be a predecessor of amphibians, reptiles, dinosaurs, mammals, and eventually humans.

Insect ecology

Ellesmere Island is noted as being the northernmost occurrence of eusocial insects; specifically, the bumblebee Bombus polaris. Interestingly, there is a second species of bumblebee occurring there, Bombus hyperboreus, which is a parasite in the nests of B. polaris.

credited to wikipedia and flickr: Russ In Oklahoma, wrk2trvl, janrobts@att.net

Haleakala

2009-03-10T11:59:00.000-07:00

Haleakalā, or the East Maui Volcano, is a massive shield volcano that forms more than 75% of the Hawaiian Island of Maui.

History

Early Hawaiians applied the name Haleakalā ("house of the sun") to the summit area only, most likely because from the west side of the island, the sun could be seen rising up over the eastern side of the mountain. In Hawaiian folklore, the depression at the summit of Haleakalā was home to the grandmother of the demigod Māui. According to the legend, Maui's grandmother helped him capture the sun and force it to slow its journey across the sky in order to lengthen the day. In modern times, Haleakalā has become synonymous with the entire East Maui volcano.

From the summit one looks down into a massive depression some 11.25 km (7 mi) across, 3.2 km (2 mi) wide, and nearly 800 m (2,600 ft) deep. The surrounding walls are steep and the interior mostly barren-looking with a scattering of volcanic cones. The volcano is officially considered active and has produced numerous eruptions in the last 30,000 years. This volcanic activity has been along two rift zones, the southwest and east. These two rift zones together form an arc that extends from La Perouse Bay on the southwest, through the Haleakalā Crater and to Hāna, to the east. The east rift zone continues under the ocean beyond the east coast of Maui as Haleakalā Ridge, making the combined rift zones one of the longest in the Hawaiian Islands chain.

Until recently, East Maui Volcano was thought to have last erupted around 1790, based largely on comparisons of maps made during the voyages of La Perouse and George Vancouver. Recent advanced dating tests, however, have shown that the last eruption was more likely to have been in the 1600s. These last flows from the southwest rift zone of Haleakalā make up the large lava deposits of the Ahihi Kina`u/La Perouse Bay area of South Maui. In addition, contrary to popular belief, Haleakalā "crater" is not volcanic in origin, nor can it accurately be called a caldera (which is formed through when the summit of a volcano collapses to form a depression). Rather, sc

ientists believe that Haleakalā's "crater" was formed when the headwalls of two large erosional valleys merged at the summit of the volcano. These valleys formed the two large gaps — Ko‘olau on the north side and Kaupō on the south — on either side of the depression.

Macdonald, Abbott, & Peterson state it this way:

Haleakala is far smaller than many volcanic craters (calderas); there is an excellent chance that it is not extinct, but only dormant; and strictly speaking it is not of volcanic origin, beyond the fact that it exists in a volcanic mountain.

National Park

Surrounding and including the "crater" is Haleakala National Park, a 28,655 acre (115.963 km²) park of which 19,270 acres (77.983 km²) are wilderness. The park includes the summit depression, Kipahulu Valley on the southeast, and ‘Ohe‘o Gulch (and pools), extending to the shoreline in the Kipahulu area. From the summit, there are two main trails leading into Haleakalā: Sliding Sands Trail and Halemau‘u Trail.

The temperature near the summit tends to vary between about 40°F (5°C) and 60°F (16°C) and, especially given the thin air and the possibility of dehydration at that elevation, the walking trails can be more challenging than one might expect. Despite this, Haleakala is popular with tourists and locals alike, who often venture to its summit, or to the visitor center just below the summit, to view the sunrise.

Astrophysical research

Because of the remarkable clarity, dryness, and stillness of the air, and its location above one-third of the atmosphere, as well as the absence of the lights of major cities, the summit of Haleakala (like Mauna Kea) is one of the most sought-after locations in the world for ground-based telescopes. As a result of the geographic importance of this observational platform, experts come from all over the world to take part in research at "Science City", an astrophysical complex operated by the U.S. Department of Defense, University of Hawaii, Smithsonian Institution, Air Force, Federal Aviation Agency, and others.

Some of the telescopes operated by the US Department of Defense are involved in researching man-made (e.g. spacecraft, monitoring satellites, rockets, and laser technology) rather than celestial objects. The program is in collaboration with defense contractors in the new Maui Research and Technology Park in Kihei. The astronomers on Haleakala are concerned about increasing light pollution as Maui's population grows. Nevertheless, new telescopes are added, such as the Pan-STARRS in 2006.

credited to wikipedia and flickr: Walt K,Madison76, Simonds

Waialeale

2009-03-07T09:42:00.000-08:00

Mount Wai’ale’ale ("rippling water" or "overflowing water" and also often spelt Waialeale in English without the ‘okina), elevation 5,148 feet (1,569 m), is a shield volcano and the second highest point on the island of Kaua’i in the Hawaiian Islands. Averaging more than 460 inches (12,000 mm) of rain over the last 32 years, with a record 683 inches (17,300 mm) in 1982, its summit is considered one of the rainiest spots on earth. It has been promoted in tourist literature for many years as the wettest spot, although the 38-year average at Mawsynram, Meghalaya, India is 11,873 millimetres (467.4 in). However, Mawsynram's rainfall is concentrated in the monsoon season, while the rain at Waialeale is more evenly distributed through the year.

Several factors give the summit of Waialeale more potential to create precipitation than the rest of the island chain:

1. Its northern position relative to the main Hawaiian Islands provides more exposure to frontal systems that bring rain during the winter.

2. It has a relatively round and regular conica

l shape, exposing all sides of its peak to winds and the moisture that they carry.

3. Its peak lies just below the so-called trade wind inversion layer of 6,000 feet (1,800 m), above which trade-wind-produced clouds cannot rise.

4. And most importantly, the steep cliffs cause the moisture-laden air to rise rapidly - over 3,000 feet (910 m) in less than 0.5 miles (0.80 km) - and drop a large portion of its rain in one spot, as opposed to spreading the rain out over a larger area if the slope were more gradual.

The great rainfall in the area produces the Alaka’i Wilderness Preserve, a large boggy area that is home to many rare plants. The ground is so wet that although trails exist, access by foot to the Waialeale area is extremely difficult.

credited to wikipedia and flickr: anand.shroff,NicBarca, volcantrek8

Bora Bora

2009-03-06T08:49:00.000-08:00

Bora Bora is an island in the Leeward group of the Society Islands of French Polynesia, an overseas collectivity of France in the Pacific Ocean. The island, located about 230 kilometres (140 mi) northwest of Papeete, is surrounded by a lagoon and a barrier reef. In the center of the island are the remnants of an extinct volcano rising to two peaks, Mount Pahia and Mount Otemanu, the highest point at 727 metres (2,385 ft). The original name of the island in the Tahitian language might be better rendered as Pora Pora, meaning "First Born"; an early transcription found in 18th- and 19th century accounts, is Bolabolla (or "Bollabolla").

The major settlement, Vaitape is on the western side of the island, opposite the main channel into the lagoon. The products of the island are mostly limited to what can be obtained from the sea and coconut trees, which were historically of economic importance for copra.

During the August 2007 census, the population on the island was about 8,880 people.

Administration

The island is administratively part of the commune (municipality) of Bora-Bora, itself in the administrative subdivision of the Leeward Islands.

The commune of Bora-Bora is made up of the island of Bora Bora proper with its surrounding islets emerging from the coral reef (29.3 km²/11.3 sq. miles in total) and of the atoll of Tupai (11 km2/4.2 sq mi), located 20 kilometres (12 mi) north of Bora Bora. The atoll of Tupai has no permanent population apart from about 50 workers in the coconut plantations.

Former President of French Polynesia Gaston Tong Sang is the current mayor of Bora Bora.

History

The Island was first inhabited by Polynesian settlers around the 4th century. Its previous Polynesian name was Vava'u.

The first European sighting was made by Jakob Roggeveen in 1722. James Cook sighted the island in 1769 and landed in 1777. A London Missionary Society arrived in 1820 and founded a Protestant church in 1822.

In 1842 Bora Bora was made a protectorate of France following the actions of Admiral Abel Aubert Dupetit Thouars.

World War II

Following the December 7, 1941 attack on Pearl Harbor by Japan, the United States entered World War II. The US chose Bora Bora as a South Pacific military supply base, and an oil depot, airstrip, seaplane base, and defensive fortifications were constructed. Known as "Operation Bobcat", it maintained a supply force of nine ships, 20,000 tons of equipment and nearly 5,000 men. Seven massive naval cannons were set up at strategic points around the island to protect it against potential military attack.

However, the island saw no combat as the American presence on Bora Bora went uncontested over the course of the war. Although the base was officially closed on June 2, 1946, many American personnel loved the island and the people that they refused to leave.

This World War II airstrip, which was never able to accommodate large aircraft, was French Polynesia's only international airport until Faa'a International Airport was opened in Papeete, Tahiti in 1962.

Today

Today the island is mainly dependent on tourism. Over the last few years several resorts have been built on motu (small islands) surrounding the lagoon.

Thirty years ago, Hotel Bora Bora built the first over-the-water bungalows on stilts over the lagoon and today, overwater bungalows are a standard feature of most Bora Bora resorts. The quality of those bungalows ranges from comparably cheap, basic accommodations to very luxurious - and pricey - places to stay. Most of the tourist destinations are aquacentric; however it is possible to visit attractions on land such as WWII cannons.

Air Tahiti has five or six flights daily to the Bora Bora Airport on Moto Mute from Tahiti.

Although French and Tahitian are the main languages spoken by the inhabitants, people in contact with tourists generally have some command of English. Most visitors to Bora Bora are American, Japanese, or European.

Public transport on the island is limited, consisting of a single bus that goes halfway around the island and back approximately every hour. Bicycles are the recommended method of transport. There are also small fun-cars for hire in Vaitape.

Bora Bora is predestined for snorkeling and scuba diving in and around its lagoon. Many species of sharks and rays inhabit the surrounding body of water. There are a few dive operators on the island offering manta ray dives and also shark-feeding dives.

credited to wikipedia and flickr: YellowPonny, Pierre Lesage

Tongariro

2009-03-05T15:07:00.000-08:00

Mount Tongariro is a volcanic complex in the North Island of New Zealand. It is located 20 kilometres to the southwest of Lake Taupo, and is the northernmost of the three active volcanoes that dominate the landscape of the central North Island.

The volcanic massif, often simply referred to as Tongariro, has a height of 1,978 metres. It first erupted about 260,000 years ago. The volcano consists of at least 12 cones; Ngauruhoe, while often regarded as a separate mountain, is geologically a vent of Tongariro. It is also the most active, having erupted more than 70 times since 1839, although the last eruption took place in 1974-1975. Activity has also been recorded at other vents. Red Crater last erupted ash in 1926 and contains active fumaroles. There are many explosion craters on the massif; water has filled some of these to form the Blue Lake and the Emerald Lakes. Mount Tongariro is in the Tongariro National Park, New Zealand's first national park and one of the earliest in the world. It given to the nation in 1887 by Te Heuheu Tukino IV (Horonuku), paramount chief of the Māori Ngati Tuwharetoa iwi in order to preserve its natural beauty.

The park also includes the peaks of Ngauruhoe and Ruapehu, both of which lie to the southwest of Tongariro. The national park is a dual World Heritage Area for its outstanding natural and intangible cultural values. The popular hiking route called Tongariro Alpine Crossing passes between Tongariro and Ngauruhoe.

Mount Tongariro and its surroundings are also one of the several locations which Peter Jackson chose to shoot the The Lord of the Rings film trilogy.

credited to wikipedia and flickr: Mwave

Tarawera

2009-02-26T10:00:00.000-08:00

Mount Tarawera is a volcanic mountain 24.1 kilometres southeast of Rotorua in the North Island of New Zealand. It consists of a series of rhyolitic lava domes that were fissured down the middle by an explosive basaltic eruption in 1886, which also killed over a hundred people. The peaks are Ruawahia Peak, Tarawera Peak and Wahanga Peak. The summit is at 1111 metres. The crater of the volcano is a series of chasms, running for 17 kilometres northeast-southwest.

The volcano is surrounded by a series of lakes, many of which were created or drastically altered in the 1886 eruption. These lakes include Lakes Tarawera, Rotomahana, Rerewhakaaitu, Okataina, Okareka, Tikitapu (Blue Lake) and Rotokakahi (Green Lake). The Tarawera River runs northeastwards across the northern flank of the mountain from Lake Tarawera.

The 1886 eruption

Shortly after midnight on the morning of 10 June 1886 a series of more than 30 increasingly strong earthquakes were felt in the Rotorua area and an unusual sheet lightning display was observed from the direction of Tarawera. At around 2:00 am a larger earthquake was felt and followed by the sound of an explosion. By 2:30 am Mount Tarawera's three peaks had erupted, blasting three distinct columns of smoke and ash thousands of metres into the sky. At around 3.30 the largest phase of the eruption commenced with a large quantity of ejecta from Rotomahana, in the form of a pyroclastic surge obliterating the Pink and White Terraces and several villages within a 6 kilometre radius.

The eruption was heard clearly as far away as Blenheim and the effects of the ash in the air were observed as far south as Christchurch, over 800 km south. In Auckland the sound of the eruption and the flashing sky was thought by some to be an attack by Russian warships.

The eruption is believed to have killed around 120 people (including seven Europeans), although it is possible that many more people died. The eruption also destroyed the world famous Pink and White Terraces and buried many Māori villages, including Te Wairoa. Approximately 2 cubic kilometres of tephra was erupted, more than Mount St. Helens ejected in 1980. Many of the lakes surrounding the mountain had their shapes and areas dramatically altered, especially the eventual enlargement of Lake Rotomahana, the largest crater involved in the eruption, as it re-filled with water. The rift created during the eruption extends 17 km across the mountain, Lake Rotomahana and through the Waimangu Volcanic Rift Valley.

The phantom canoe

One pervasive legend of the 1886 eruption is that of the phantom canoe. 11 days before the eruption, a boat full of tourists returning from the Terraces saw what appeared to be a war canoe approach their boat, only to disappear in the mist half a mile from them. One of the witnesses was a clergyman. Nobody around the lake owned such a war canoe, and nothing like it had been seen on the lake for many many years.

Though skeptics maintained that it was a freak reflection seen on the mist, tribal elders at Te Wairoa claimed that it was a waka wairua (spirit canoe) and was a portent of doom.

It has been suggested that the waka was actually a freak wave on the water, caused by seismic activity below the lake, but locals believe that a future eruption will be signalled by the reappearance of the canoe.

credited to wikipedia and flickr: Gregory Melle

Milford Sound

2009-02-26T09:44:00.000-08:00

Milford Sound (Piopiotahi in Māori) is a fjord in the south west of New Zealand's South Island, within Fiordland National Park and the Te Wahipounamu World Heritage site. It has been judged the world's top travel destination in an international survey, and is acclaimed as New Zealand's most famous tourist destination. Rudyard Kipling had previously called it the eighth Wonder of the World.

Etymology

Milford Sound is named after Milford Haven in Wales, while the Cleddau River which flows into the sound is also named for its Welsh namesake. The Māori named the sound Piopiotahi after the thrush-like piopio bird, now extinct. Piopiotahi means "a single piopio", harking back to the legend of Māui trying to win immortality for mankind - when Maui died in the attempt, a piopio was said to have flown here in mourning.

Geography

Milford Sound runs 15 kilometres inland from the Tasman Sea and is surrounded by sheer rock faces that rise 1,200 metres or more on either side. Among the peaks are The Elephant at 1,517 m (4,977 ft), said to resemble an elephant's head, and Lion Mountain, 1,302 m (4,271 ft), in the shape of a crouching lion. Lush rain forests cling precariously to these cliffs, while seals, penguins, and dolphins frequent the waters.

Climate

With a mean annual rainfall of 6,813 mm on 182 days a year, a high level even for the West Coast, Milford Sound is known as the wettest inhabited place in New Zealand and one of the wettest in the world. Rainfall can reach 250 mm during a span of 24 hours. The rainfall creates dozens of temporary waterfalls (as well as a number of major, more permanent ones) cascading down the cliff faces, some reaching a thousand metres in length. Smaller falls from such heights may never reach the bottom of the sound, drifting away in the wind.

Accumulated rainwater can at times cause portions of the rain forest to lose their grip on the sheer cliff faces, resulting in tree avalanches into the sound. The regrowth of the rain forest after these avalanches can be seen in several locations along the sound.

History

Milford Sound was initially overlooked by European explorers, because its narrow entry did not appear to lead into such large interior bays. Sailing ship captains such as James Cook, who bypassed Milford Sound on his journeys for just this reason, also feared venturing too close to the steep mountainsides, afraid that wind conditions would prevent escape.

While Fiordland as such remained one of the least-explored areas of New Zealand up to the 20th century, Milford Sound's natural beauty soon attracted national and international renown, and led to the discovery of the McKinnon Pass in 1888, soon to become a part of the new Milford Track, an early walking tourism trail. In the same year, the low watershed saddle between the Hollyford River and the Cleddau River was discovered, where the Homer Tunnel was to be developed about sixty years later to provide road access.

credited to wikipedia and flickr: BigFrank

Egmont

2009-02-25T11:06:00.000-08:00

Mount Taranaki or Mount Egmont is an active but quiescent stratovolcano in the Taranaki region on the west coast of New Zealand's North Island. The 2518-metre-high mountain is one of the most symmetrical volcanic cones in the world. There is a secondary cone, Fanthams Peak, on the south side. Because of its resemblance to Mount Fuji, Taranaki provided the backdrop for the movie The Last Samurai.

Taranaki is geologically young, having commenced activity approximately 135,000 years ago. The most recent volcanic activity was a moderate ash eruption, of the size of Ruapehu's activity in 1995/1996, that occurred about 1755 and possibly in the early 1800s, and the last major eruption occurred around 1655. Recent research has shown that over the last 9000 years minor eruptions have occurred roughly every 90 years on average, with major eruptions every 500 years.

Hazards

Taranaki is considered unusual in that it has experienced at least five of its major eruptions by the method of cone collapse. Few volcanoes have undergone more than one cone collapse. The vast volume of material involved in these collapses is reflected in the extensive ringplain surrounding the volcano. There is also evidence of lahars being a common result of eruption.

Much of the region is at risk from lahars, which have reached as far as the coast. A volcanic event is unnecessary: even earthquakes combined with heavy rain or snow could dislodge vast quantities of unstable layers resting on steep slopes. Many farmers live in the paths of such possible destructive events.

Although volcanic eruptions are notoriously chaotic in their frequency, some scientists warn that a large eruption is "overdue". Research from Massey University indicates that significant seismic activity is likely again in the next 50 years. Prevailing winds would probably blow ash east, covering much of the North Island, and disrupting air routes, power transmission lines and local water supplies.

The mountain's name

For many centuries the mountain was called Taranaki by Māori. Captain Cook named it Mount Egmont after John Perceval, 2nd Earl of Egmont, the First Lord of the Admiralty who promoted Cook's first voyage. It appeared as Mt Egmont on maps until the 1980s, when it was ruled that the official name is Mount Taranaki or Mount Egmont, although most regard the two names as interchangeable. The Egmont name still applies to the national park that surrounds the peak. The name Mount Taranaki is linguistically redundant, since the word tara means mountain peak. Naki is thought to come from ngaki, meaning shining, a reference to the snow-clad winter nature of the upper slopes. Geologists refer to it as the Egmont Volcano.

Confiscated from Maori

In 1865 the mountain was confiscated from Māori by the New Zealand Government under the powers of the New Zealand Settlements Act 1863, ostensibly as a means of establishing and maintaining peace amid the Second Taranaki War. The legislation was framed with the purported intention of seizing and dividing up the land of Māori "in rebellion" and providing it as farmland for military settlers. The mountain was confiscated despite clear evidence it was unusable for farming and otherwise uninhabitable.

The mountain was returned to the people of Taranaki in 1978 by means of the Mount Egmont Vesting Act 1978, which vested it to the Taranaki Maori Trust Board. By means of the same Act, it was immediately passed back to the Government as a gift to the nation. The Waitangi Tribunal, in its 1996 report, Kaupapa Tuatahi, observed: "We are unaware of the evidence that the hapu agreed to this arrangement. Many who made submssions to us were adamant that most knew nothing of it." It cited a submission that suggested the political climate of 1975 was such that the board felt it was necessary to perform a gesture of goodwill designed to create a more favourable environment within which a monetary settlement could be negotiated.

National park

In 1881, a circular area with a radius of six miles (9.6 km) from the summit was protected as a Forest Reserve. Areas encompassing the older volcanic remnants of Pouakai and Kaitake were later added to the reserve and in 1900 all this land was gazetted as Egmont National Park, the second national park in New Zealand. With intensively-farmed dairy pasture reaching right up to the mostly-circular park boundary, the change in vegetation is sharply delineated in satellite images.

Recreation

The Stratford Mountain Club operates the Manganui skifield on the eastern slope. Equipment access to the skifield is by flying fox across the Manganui Gorge.

The Taranaki Alpine Club maintains Tahurangi Lodge on the north slope of the mountain, just next to the television tower. The lodge is frequently used as the base for public climbs to the summit held in the summer months. The various climbing and tramping clubs organize these public events and provide informal guides.

Taranaki is a relatively easy mountain to climb and many do so each summer. It takes a reasonably fit person a day to make the up-and-back climb. However, weather on the mountain can change rapidly, catching inexperienced trampers unawares. A number of people have died on the mountain after being caught unprepared in bad weather. This mountain is possibly the most dangerous in New Zealand, with a reputation for the highest annual fatalities.

Mythology

According to Maori mythology, Taranaki once resided in the middle of the North Island, with all the other New Zealand volcanoes. The beautiful Pihanga was coveted by all the mountains, and a great battle broke out between them. Tongariro eventually won the day, inflicted great wounds on the side of Taranaki, and causing him to flee. Taranaki headed westwards, following Te Toka a Rauhotu (the Rock of Rauhotu) and forming the deep gorges of the Whanganui River, paused for a while, creating the depression that formed the Te Ngaere swamp, then heading north. Further progress was blocked by the Pouakai ranges, and as the sun came up Taranaki became petrified in his current location. When Taranaki conceals himself with rainclouds, he is said to be crying for his lost love, and during spectacular sunsets, he is said to be displaying himself to her. In turn, Tongariro's eruptions are said to be a warning to Taranaki not to return.

Access

There are three roads leading part-way up the mountain. The highest is to East Egmont plateau, with a viewing platform and parking facilities for the skifield. It lies at the transition between subalpine scrub and alpine herbfields.

There are park visitor centres at North Egmont and at Dawson Falls on the southeast side.

The eastern side from Stratford leads to the Stratford Mountain House, and the ski field.

There is no road access on the western side. However, a road winds for 10 km though native bush over the saddle between Pouakai and Kaitake. Near the top of this road is the renowned Pukeiti Trust rhododendron garden.

Older volcanoes in the area

Taranaki sits upon the remains of three older volcanic complexes which lie to the northwest. The Indo-Australian Plate is slowly moving relative to the magma source which feeds these volcanoes. This trend is reflected in Fanthams Peak, the newer secondary cone on the southeast side of Taranaki.

The oldest volcanic remnants consist of a series of lava plugs: Paritutu rock (156m), which forms part of New Plymouth's harbour, and the Sugar Loaf Islands close offshore. These have been dated at 1.75 million years.

On the coast 15 km southwest of New Plymouth is the Kaitake range (rising to 682m), last active approximately 500,000 years ago.

Nearest to Taranaki is the Pouakai complex. Pouakai may have originated around the same time as Kaitake but remained active until about 240,000 years ago. Much of Pouakai's large ringplain was obliterated by the Egmont Volcano, the hills near Eltham being the only remnant to the south.

credited to wikipedia and flickr: Alex Cowley