Sand: an investigation into a disappearance. Shown last night on ARTE, the European culture channel, this superb documentary by Denis Delestrac has already made waves. It has also provided me with a great deal of pleasure and satisfaction – last year, Denis filmed a long piece of yours truly holding forth on the topic and extracted a number of choice selections for inclusion in the documentary. So, last night, for the first time, I sat and watched myself on TV…..

The film also includes wise words from, amongst others, Orrin Pilkey, Professor Emeritus of Geology at Duke University, whose work I have highlighted several times in this blog. The documentary can be viewed in its entirety at http://www.arte.tv/guide/fr/046598-000/le-sable-enquete-sur-une-disparition – in French, but it has been taken up by PBS in the US, so watch out for the English version being broadcast. Originally titled Sand Wars, it does a great job of raising awareness of an environmental issue rarely brought to the public’s attention – the way that we exploit our unsung hero is not sustainable.   

Thank you Denis!

“One grain of sand, it is all that remains of my vast empire." This line is from the classic film The Never Ending Story. When the mythical land of Fantasia is destroyed, the protagonists are able to wish it back into existence using that one grain of sand, which had escaped destruction. If I could have wished Rockaway back to normal using sand I would have been in luck. Because of our sand? Instead of disappearing it climbed into our houses, streets, cars, beds, bathtubs and just about every other imaginable place.

As Memorial Day approaches one can feel the return to normalcy knocking at the door. Some of the signs of destruction haven't quite left us yet, although more and more our hometown is starting to feel like itself again.

One of the ways that I kept my head through the storm and the winter months that followed was by remembering what I love most about living here. The beach. Every morning, I walk the shoreline with my pooch. Today I invite you to join me, to see what we find in the sands of Rockaway.

Our first find, a paper plate with a child’s drawing on it.

Next, Nina and I encountered this guy, in quite a compromising position.

It’s a bit of a hobby of mine to rescue horseshoe crabs that end up flipped over and helpless. After he was vigorously sniffed, he was re-released into the wild

Next up, this purple broom head.

Lines in the sand that remind me of tree branches.

A series of seashells and sea glass.

A little patterned feather.

And a shred of yellow caution tape.

So there you have it, the best of one morning’s exploration in the sand along the shore. And should the day ever come when I can wish upon a sand grain, I’ll be in luck. Right now, there are about a thousand of them in my shoes.

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[As I wrote in my previous post on the rebuilding of Breezy Point, Susanne, a resident of neighbouring Rockaway, contacted me about using Larry Deemer’s photos on her Rockaway Rises blog (which she started because she “was tired of looking at all the negative news stories and photography about Rockaway.” Larry was, of course, delighted, and Susanne used some of his Wave to Wave photos from his book of the same title. It also seemed like a great opportunity for a guest post, and Susanne kindly agreed – this is the very enjoyable result. Susanne grew up in Breezy Point and is a freelance photographer and photo editor who “spent several weeks after Hurricane Sandy digging out my parents’ flooded basement before driving to Florida where I had to stay for 6 weeks because my office had also been flooded and my job temporarily moved down there.” Thanks for this post, Susanne, and best wishes for a great Memorial Day weekend to you and everyone in Rockaway and Breezy Point.]

Back in the very early days of this blog, one of the great and rewarding pieces of serendipity was getting to know Larry Deemer, sand aficionado and photographer extraordinaire. I first published a selection of his stunning images back in April 2009, and there have been subsequent collaborations on ice, horseshoe crabs, and scale. And in the meantime, he has published a glorious book of his sand pattern images. Most importantly, also in the meantime, we have become good friends and it’s a great pleasure to post a selection of his latest photos of the creative conspiracy between waves, foam, and sand.

But there’s a backstory, and a dramatic one. In that first post I wrote that Larry is “lucky enough to live in Breezy Point, a coastal neighbourhood in Queens, the borough of New York City,” and indeed my wife and I were lucky enough to visit Larry, Lou, and Buck and enjoy their company, their home, and their beach. But then, in October of last year, Hurricane Sandy rolled the dice and the luck of the residents of Breezy Point changed – catastrophically. They were hit not only by damage from the storm (which would have been relatively manageable), but by a devastating fire that raged out of control and destroyed over a hundred homes. Over 200 more were terminally damaged and have been bulldozed. Larry was, in this sense, lucky: the water damage to their house was reparable and they have been back home since the middle of January, feeling, as Larry has commented, “like pioneers.” But not home as it used to be – houses around them are no longer there, and the process of rebuilding is stalled by the absurdities of bureaucracy. We use the term “community” somewhat loosely these days, but Breezy Point was – and is – a real community; just read some of the stories on the web to appreciate what the word really means.

But nature continues her activities, oblivious to human hardship, and the beach, although “the 6’ dunes are now 2’ dunes',” continues to be an inspiration. Thanks, Larry.

[Soon after writing this post, I heard from Susanne Rieth who runs a blog called Rockaway Rises - Rockaway is right next to Breezy Point. The blog is well worth a look, described thus: "Rockaway Rises is a community for sharing and enjoying the positive aspects of life on our fair peninsula.  We welcome submissions of photography, art work and uplifting stories that remind us why we love it here, and why we will continue to thrive here in spite of Hurricane Sandy.  No devastation and destruction.  Only gratitude for what we still have, the ocean and our community."] 

The differences in the coastal geomorphology along the Pacific coast of Tohoku in part controlled the impact of the Tohoku-oki tsunami. a. The steep sided valleys of the Sanriku coastline focussed the tsunami waves causing a run up height of approximately 40 m above sea level. b. In contrast along the low lying Sendai Plain, the wave height was much less but it travelled much further inland, with a  maximum inundation from the shoreline of 5.4 km. Image courtesy of Kazuhisa Goto (Chiba Institute) 

A couple of years ago, I wrote something of a rant on the topic of listening to geologists in order to save lives. The post, Ignoring tsunami records: hubris, complacency, or just human nature? was in the aftermath of the catastrophe in Japan and reflected on what could – should – have been learned from historical and geological testaments. Now, thanks to a research report in Geology Today on the papers published last year in a special issue of Sedimentary Geology, we have a view of what has now been learned, geologically at least, in the aftermath of the events of 2011.

The lead review paper in the journal, titled The future of tsunami research following the 2011 Tohoku-oki event, is by Kazuhisa Goto of Japan’s Planetary Exploration Research Center, Chiba Institute of Technology, and the International Research Institute of Disaster Science, Tohoku University, together with colleagues from Australia and the US. Their opening and closing comments are worthy of attention:

The 2011 Tohoku-oki tsunami was the first example of a large, low-frequency event occurring where historical and pre-historical tsunamis were already known to have occurred through historical… and geological evidence... Magnitudes of some of the historical earthquakes and their associated tsunamis had also been estimated based on the known geological record and numerical modelling... This point was highlighted by media soon after the 2011 event because such information had not been taken into account in the tsunami disaster prevention plan for the Pacific coast of Tohoku….

It is indeed true that geology is vital to gaining a better understanding of past tsunamis along any coastline and to interpreting the hydrodynamic features of paleotsunamis. However, the 2011 Tohoku-oki tsunami event tells us that there is still much to be learnt from tsunami deposits if we are to produce reliable tsunami risk assessments. Following the 2011 Tohoku-oki tsunami, we must return to the key question – why were the results of geological studies of the AD869 Jōgan event not incorporated into disaster prevention plans in Japan? Although most geological studies of the AD869 Jōgan tsunami had not been published in mainstream, peer-reviewed international journals, the results were nonetheless high quality and well disseminated. The AD869 Jōgan tsunami was indeed one of the best studied events in the world. However, Goto et al. (2012) candidly admit that tsunami geology is not a mature discipline and that prior to the 2011 earthquake it had not reached a sufficient level of recognition in Japan where researchers and disaster prevention experts from various fields were interacting effectively. Furthermore, in general terms, people continue to be unable to comprehend the significance and relevance of extreme events that occur on timescales spanning several 100s-1,000s of years that far exceed the human (or building) lifespan. This is where much of the challenge lies for tsunami scientists in education outreach to the general public.

The results that they report are fascinating, startling, and sobering – Geology Today provides a useful summary:

Future research following the 2011 Tohokuoki eathquake and tsunami

On 11 March 2011 a magnitude Mw 9.0 earthquake occurred off the Pacific coast of Tohoku District Japan, generating a major tsunami which caused widespread damage along the east coast of Japan and coastal areas around the whole Pacific basin. This event, referred to as the Tohoku-oki (oki means offshore in Japanese) generated a huge tsunami, with a run up height of up to 40 m, resulting in 15,868 dead and 2,848 missing, along with substantial damage, including that at the Fukushima Daiichi nuclear power plant. The damage and death-toll was despite the fact that the Pacific coast of Tohoku was one of the best prepared for a tsunami in the country. However, the event has also allowed researchers to look at the effects of this very well documented tsunami and to enable them to better interpret the historical sedimentary record to re-evaluate the magnitude of previous events. Such work is very important when developing tsunami disaster prevention plans.

Recently a special issue of the journal Sedimentary Geology has been devoted to the ‘2011 Tohoku-oki tsunami’. This special issue comprising 15 papers based on surveys and numerical modelling in Japan, along with one paper on the effects of the tsunami in the USA is prefaced by a review article by Kazuhisa Goto and colleagues looking at the sedimentological effects of the tsunami, future research arising from this event and also the social relevance of this research in the aftermath of the tsunami (Sedimentary Geology, 2012, v.282, pp.1–13).

The Pacific coast of Tohoku is divided into the Sanriku ria coast in the north and coastal plain areas such as Sendai in the south. The Sanriku coast is characterised by narrow drowned valleys, which have been damaged by tsunamis every few tens to hundreds of years [header image]. In contrast the Sendai plains are an alluvial lowland, with a beach, coastal dune ridges up to several metres high covered by pine forests, and low lying former wetlands and rice paddies. In this area there is no historical record of large tsunamis over the last thousand years, except for one possible event in 1611, although small tsunamis are recorded. These differences in the coastal geomorphology had marked effects on the tsunami wave. On the Sanriku coast, its steep and narrow valleys focussed the wave, generating the largest run ups, with a maximum rise of 40.4 m above sea level, although the inundation distance inland was relatively short, being generally up to 2 km. In contrast on the Sendai Plain, the tsunami travelled up to 5.4 km inland, but the wave height reached a maximum of only about 19 m. In the offshore area, about 1 km from the coastline, video footage has allowed a flow speed of 14 m/s to be calculated, although near Miyako sequential photographs taken from high ground suggest that the incoming wave velocity may have reached 32 m/s. In contrast, on land the flow speeds are variable as a result of the surface conditions, with estimates ranging between 3 and 8 m/s.

 Sediment deposits from the tsunami included deposits of sand and mud across the Sendai Plain, along with gravel deposits and locally extremely large boulder deposits. Image courtesy of Kazuhisa Goto 

Following the tsunami, rapid geological surveys were conducted to gain an understanding of the types of sedimentary deposits resulting from an event of this magnitude. On the Sendai Plain a sand layer extended some 3 km inland which continued as a mudstone layer almost to the maximum inundation limit of 5.4 km [image above]. This unit reached a maximum thickness of 30 cm and generally thinned inland. This bed was typically parallel laminated or structureless sands and silts with fragments of wood, glass and ripped up mud clasts overlying an erosional base. Based on an analysis of its heavy minerals, microfossils and isotope chemistry, it appears that most of the deposited sediment on the Sendai Plains was derived from beach, sand dune, lagoon and inland soils with only a minor contribution from offshore sediments. Importantly, it was recognized that a lot of the sediment resulted from liquefaction, with sand being vented from beneath the soils in the rice paddies. In contrast, on the Sanriku coast, the deposited sediment comprised both the eroded beach sands but also marine sediment from both the inner bay and even more pelagic areas.

In addition to the deposition of sands and muds, granule to boulder sized clasts were also observed. In some cases gravel deposits were up to 1 m thick and thinned landward. Boulder deposits were also observed, including large reworked fragments of concrete from the coastal defences, with the largest observed natural boulder being 6.5 × 2.5 × 2.4 m in size.

Offshore, within coastal bays and harbours there was evidence for both erosion, but also sediment deposition with the formation of large-scale submarine dunes. Further offshore at water depths between 300 and 5940 m the seafloor was covered by muddy sediments, in areas that prior to the earthquake had sandy or gravel surfaces. These sediments are interpreted as the deposits of turbidites, resulting from the tsunami backwash. Other turbidite deposits between 1 and 25 cm thick were observed in cores recovered offshore from the Sendai and Sanriku coastline, and caesium-134 and caesium-137 released from the Fukushima-Daiichi nuclear plant was detected on the top of these deposits.

Such sedimentological studies as these are critical for us to correctly interpret the ancient record of past tsunami events, which in turn help us understand the scale and frequency of past events. This is indispensable in developing tsunami risk assessments, and the improvement of disaster prevention measures.

[I have to admit that I refrained from commenting that Kazuhisa Goto was the guy they should have gone to when planning tsunami defences, but it seemed – and probably still is – inappropriate. His 2012 article is online in English. The complete list of all the papers in the journal can be found at http://www.sciencedirect.com/science/journal/00370738/282. The full articles are behind the pay wall, but I will be happy to supply a PDF for personal use if any reader would be interested.]