Through The Sandglass

"I'm real concerned about the beach"

 

So declared Dennis Dare, a Manager of Ocean City, Maryland, after the conspiracy of a nor'easter and the remnant of tropical storm Ida wrought havoc along the coasts of the northeastern US over the last few days. His concern was well placed - much of the beach simply wasn't there any more, instead there was a twelve-foot cliff marking the extent of relentless wave erosion. Ocean City engineer Terry McGean, after inspecting the scene, is reported as saying “We lost a lot of dune. We lost a fair amount of beach. We’ve seen worse. Certainly, the idea is that we lose sand and not buildings, so it did its job. Now we get everybody rolling to get it back together”; he went on to describe how when it comes time to reload the beach with sand next summer, it’s going to be more expensive and take more sand than they’d planned for. He said the beach lost between 25-50 percent of its dunes.

"Reload the beach" ? I suppose he must be referring to the time-honoured futility of beach nourishment.

The press reports contain many dramatic images and I shall simply reproduce some of my favourites here, with quotations from the accompanying descriptions.

 

"Coastal community leaders said Saturday they were crossing their fingers that the waves would send enough sand back up onto the beaches that human assistance wouldn't be needed to finish the replenishment, shoring up the resorts in time for the economically vital summer."

 

"In Delaware, tides washed out dunes, leaving several feet of water and 3 feet of sand along state Route 1. Transportation officials say it may take two days to clear the sand."

 

"Several vessels carrying hazardous cargo broke loose from their moorings in Virginia during the storm. Crews were working to stabilize a 570-foot barge carrying containers of chemicals in the Sandbridge area of Virginia Beach. Work crews boarded the barge and were riding out the storm with it, hoping it would run aground and could be towed away when the weather improves. A similar fate awaits a 700-foot oil tanker that broke loose and ran aground on a sandbar in the James River in Newport News, Va."

 

"But even if another storm were to hit today, the sand washed away from the dunes will still be of some help, creating a larger near-shore sandbar system that serves to break the waves' energy as they pound the coast. That effect was apparent Friday afternoon, Tony Pratt, Delaware's shorelines and waterway administrator said. "The waves really were breaking quite a distance from the dune by the end of the day ... and losing a tremendous amount of their energy," he said. 'I like it better when the dune is whole, [but] that sand is still serving a great service. ... It's not like a total loss.' "

"Beach replenishment is a costly endeavor. A project earlier this year in Dewey Beach alone cost $6 million. "We're hopeful that Mother Nature will do her job," said Carol Everhart, executive director of the Rehoboth Beach-Dewey Beach Chamber of Commerce. Since 2001, the Army Corps and others have spent $100 million pumping sand from the ocean onto Delaware's beaches. Building sea walls will cost much more -- a sea wall built in Galveston, Texas, cost $10,000 a foot."

 

"State and local beach officials have credited the dunes with defending their towns' homes and boardwalks from the storm's wrath.

Taking an opposite view is Orrin H. Pilkey, emeritus professor in the Nicholas School of the Environment at Duke University and author of "The Corps and the Shore" and this year's "The Rising Sea," which he co-authored.

Pilkey said it would be a huge error for Delaware to ignore science and not plan for the inevitable approach of climate change and rising seas. He pointed to the damaging Ash Wednesday storm of 1962, when the Army Corps of Engineers erected a dune along the shore in Ocean City, Md., and issued an advisory to restrict development inland of the protective barrier. But homes and hotels eventually moved oceanside, on top of and across the dune.

'The town paid no attention to it -- it had no teeth,' Pilkey said. 'Money speaks -- so away we went.' "

[I couldn't possibly comment further on all this - the images and the quotations speak for themselves. Many of the images are from http://www.delawareonline.com/, and http://www.nj.com/, credits Patti Sapone, Robert Sciarrino, Chuck Snyder, Laura Emmons]

An anniversary

The Nima Sand Museum on the coast of Japan's main island of Honshu contains the world's largest sandglass. Six meters in height, it is ceremonially turned at midnight on December 31st every year - and takes until exactly a year later for all the sand to fall. If, instead of December 31st, the giant sandglass had been turned on November 11th, 2008, when the first post on Through the Sandglass was published, the last grains would be trickling through today. I find it difficult to believe that this rather eclectic blog has been on the go for a year; I started it initially at the suggestion of my publishers as a follow-up to the book, but it has taken on a life of its own. There remain endless topics deposited on the cutting room floor after the book was edited that I still haven't got round to covering - there just seem to be too many other things of interest (to me, at least) cropping up on a daily basis.

So, more than 120 posts later and after visits from people in 105 countries, I'm quietly celebrating my first year of blogging ("quietly" meaning a particularly good bottle of red wine, nothing more exuberant). It has been great fun and has given me the great pleasure of putting me in touch with all kinds of delightful people around the world - something that otherwise would never have happened.

So I want to sincerely thank everyone who reads this blog, whether routinely or just occasionally.

And please keep the comments, suggestions, links and references coming - they're much appreciated.

Meanwhile, I'll leave you with this: I sometimes fear that my obsession distorts the true frequency of mentions of my topic - but then I watched the news last week and, in one broadcast, were the images below (from the recent G20 finance meeting in St. Andrews, Scotland) and a description of yet another line being drawn in the sand. Put that phrase into google news search and there are 500 instances of its use in the last week. I rest my case. 

 

P.S. it seems that almost all the images on the blog have spontaneously and unilaterally decided to de-centre and left-justify themselves, detracting from the appearance - I have no idea why and am seeking the help of the experts at Typepad. Any suggestions will be most welcome.

Ten things we don't know about sand: Number 2

 

It just won't stop cropping up. After I returned from giving the talk in Manchester, checking through the news in the world of science, not only did I come across impressive progress in coastal research (my number 6 unknown ), but there, in Wired Science, was a report titled "Baffling Patterns Form in Scientific Sandbox." It began "With nothing more than beads in a glass box, physicists have revealed yet another mysterious property of granular solids, now recognized by scientists as a unique state of matter, like solids or gases" - my number 2 in the ten things we don't know about sand: "What is it?"

The report describes work by Ralf Stannarius and Frank Rietz of the Otto von Guericke-University Magdeburg in Germany; using, as is so often the case when investigating the bizarre behaviours of granular materials, very simple apparatus, they have produced some quite astonishing results. Results that demonstrate, yet again, that we don't really know how to describe granular materials - they are not consistently solids or liquids, but rather a state of matter in their own right. We don't really know how many states of matter there are - in addition to the solids, liquids, and gases, there are numerous other candidates, including liquid crystal, amorphous, Bose-Einstein condensates, and, of course, the notorious quark-gluon plasmas (all this, I will readily admit, from Wikipedia, where I also discovered something called a "superglass" - but the article was categorised as an "orphan"). As Heinrich Jaeger, the granular guru, remarked when talking about his recent work on the nano-scale forces causing droplet formation in falling streams of sand, these "experimental results open up new territory for which there is currently no theoretical framework." 

The fact that granular materials do not like to remain mixed has long been observed, and Stannarius and Rietz describe earlier experimental work which their latest research continues. Put a granular mixture in a container and vibrate, shake, rotate, or otherwise disturb it and it will perpetrate an act of self-segregation. Stannarius and Rietz have shown that such a mixture not only self-segregates, but convects. In the image at the top of this post (from their publication), it almost seems as if the material is mocking us, saying "hey, you'll need better spectacles than these through which to understand what we're up to" (OK, blogger's poetic license). "On the Brink of Jamming: Granular Convection in Densely Filled Containers" by Rietz and Stannarius was first published last year, but last month they released an update with compelling and extraordinary videos of granular convection. The apparatus was, indeed, simple, but clever. As shown below, they used a simple mix of two sizes of glass sand-sized beads in a container that is essentially a Hele-Shaw cell, just like the home-made one I have used in my kitchen physics experiments. Once filled (and it is important that the cell is filled beyond a critical level), it's placed in a mechanism that simply rotates it, slowly, for hours. The cell is back-lit and photographed periodically.

 

The results are staggering. The movies, of various runs of the experiment and at various resolutions, can be found at the Magdeburg website (caution: if you go to the MIT Technology Review report, the movie link embedded there is for a 150 mb version - better to check out the link I've just mentioned). The movies are dramatic and well-worth watching, but just to whet your appetite, I've assembled a time-series of stills, shown below.

 

In a completely unpredictable (and unpredicted) way, the grains develop a graceful series of dynamically sustained convection rolls. As the authors wrote, "Known mechanisms for granular convection could not be applied." Another echo of Heinrich Jaeger's comment that "Physicists have a rich toolbox for dealing with solids, liquids and gases. But we don’t have a manual for when the old categories don’t apply." Whatever next in the mysterious world of granular materials?

Arenaceous sporting trivia - the baseball World Series

 

My daughter and her grandfather, both in Philadelphia, will probably, to put it mildly, have less than kind words for me when they see this post. For the Phillies (last year's champions) were beaten in the baseball World Series last night by the New York Yankees - of all teams, it had to be the Yankees (for non-North American readers, I have appended some brief explanatory notes at the end of the post). Angst, tears, and rage in Philadelphia, exuberant celebration in New York. But, for Through the Sandglass, it's just another opportunity, to point out the ubiquity of my topic - in the continuing tradition of my daughter's Simpsons challenge.  

For a start, like many sporting surfaces, the construction of a world-class baseball field relies on first-class sand. The iconic diamond, its grass and its surrounding "dirt," are made from specialty materials. Go to the website of the Beam Clay company of Great Meadows, New Jersey ("Your 'one-stop source' for America's baseball and sports turf surfaces and supplies!") and you will be bewildered by the choice of over 200 products for the construction, care, and maintenance of your dream infield - for example, their "Premium infield mix":

Made from uniform orange sand and red Beam Clay® with our special binding process that reduces wind and water erosion. Doesn’t separate and blow away! Doesn’t become dusty in stadiums! With proper maintenance, provides firm traction without tracking, good drainage while retaining playing moisture, distinctive reddish/orange color, works up readily, no separation of ingredients, long lasting, safe to slide on - for safe, attractive, consistent professional quality baseball diamonds.

The nature and performance of the materials used for the batter's and catcher's boxes are particularly important, but as in the action of a game, the pitcher's mound has to be a focus of attention. A good history of the pitcher's mound and how to construct one can be found here; the ingredients and recipes vary little - although the climatic environment of the stadium is important. This particular summary is from http://www.baseball-almanac.com/:

The mix used to build the pitcher's landing area (and often the batter's box and catcher's box) should have a significant concentration of clay to provide the necessary stability to resist degradation from increased traffic. A good material will be about 40% sand, 20% silt, and 40% clay. If necessary, you can mix individual components together. Just be sure that individual components are evenly distributed throughout the material.

     A quality infield material will have a lower concentration of clay than the pitcher's mound. The infield skin should be moist and firm, not hard and baked dry. To achieve firmness, an infield mix should not be too sandy. An infield mix with greater than 75% sand causes unstable footing for ballplayers and increases infield skin maintenance problems. A sandy infield will create low spots more quickly and is more likely to create lips at the infield skin/turf interface. Ideally, the infield mix should be between 50% and 75% sand and 25% to 50% clay and silt. A combination that has been successfully used is a 60% sand, 20% silt, 20% clay base mix (sandy clay loam to sandy loam). The silt and clay give the mix firmness. If the mix contains too much silt and clay, compaction and hardness become a problem.

So, a skilful (and well-paid) pitcher can stride out to his patch with confidence that its consistency will provide a reliable foundation for his art. And, in the case of Mariano Rivera ("Mo"), who finished off the Phillies last night and has been called "the best closer in the history of the game," his appearance on the field - if the game is in New York - is accompanied by a loud rendition of Metallica's "Enter Sandman" - "we're off to never-never land." It is said that this is by no means Mo's favourite song, but that it is played on his entry because when he comes into a game, you can pretty much put it to bed. If you wish, you can see a video of this from last night's game at http://www.wikio.com/video/1925785.

And then, of course, there's sand lot baseball. And plastic baseball-shaped bottles that can be filled with coloured sand - but one example of a wide range of such things; I couldn't possibly comment on their artistic merit - but I suspect that Andrew Clemens will not be rolling in his grave..... 

 

Notes for non-American readers:

1. The "World Series" has been widely derided by non-North Americans as being no such thing, since no countries other than the USA and Canada can compete for it. In order to combat such accusations of sporting arrogance, it has often been declared that the name originates from the original sponsorship of the championship by the newspaper, The New York World, early in the last century. Indeed, my (American) wife firmly corrected me to this effect a long time ago. But it's a myth - the "World Series" is, and always has been, exactly that (see Snopes). Not that I would in any way revert to my earlier derisive remarks ..... Always remember that the other life of Steve Gould, the extraordinary and revered evolutionary biologist and writer, was as a devoted and passionate baseball fan - of the Yankees. 
2. I would no more attempt to explain baseball to non-Americans than I would cricket to baseball fans (both are challenges equivalent, in Shakespeare's words, to "numbering the sands and drinking the oceans dry.") Suffice it to say that both games are very much like the classic description of a soldier's life - long periods of boredom interrupted by brief moments of terror (well, generally not exactly terror, but action, something to actually engage the senses and the emotions).
3. In the later stages of a game, the starting pitcher is often replaced by a specialist finisher - a "closer" like Mariano Rivera.
4. A baseball signed by Mo and with the words "Enter Sandman" can be purchased from http://www.mlbfansite.com/ for a mere $399.99 (knocked down, so to speak, from the original price of $501.86).
5. Herewith, from http://www.baseball-almanac.com/stadium/baseball_field_construction.shtml, a simple illustration of the layout of the diamond and the infield. From now on, you're on your own.
   
   
   
   
   

Too much, too little, and often in the wrong place

 

It rose out of the omnipresent sand of a natural island, and there remains a thin layer of the ocher substance almost everywhere: on the canopied grandstands, on the brilliantly lighted hotel at the edge of the track, on the seats and in just about every corner of the Yas Marina Circuit in Abu Dhabi.

So went the start of a New York Times article on yesterday's finale to the Formula One Grand Prix season. Small armies of workers were sweeping the sand right up to the last minute and yet, as The Walrus and The Carpenter observed, it's essentially an impossible task. Holding an extravaganza of highly sophisticated but delicate technology in this kind of environment brings many challenges. As the article went on to comment

 It may play havoc with the engines of the cars and it will change the grip, lap by lap, for the drivers, even affect the lenses and other camera mechanisms belonging to the hundreds of photographers and journalists who will document the final race

For races in neighbouring Bahrain, it's long been a problem, as explained by Red Bull’s technical director Gunther Steiner:

You have to be aware that it can get in to every part of the car. It literally sandblasts the car every time it goes on track and gradually erodes all the surfaces and the cooling fins on the radiators.

Unique measures are taken to protect exposed suspension and other parts of the cars, and specially designed air filters have to be used. And then there's the problem with grip and tyre selection - after all, a motor race in which the drivers have to go slowly in order to stay on the track - and avoid whole sections of it because it's covered in sand - detracts somewhat from the sporting attraction. David Coulthard, the now-retired driver, was quoted before the race as saying

It does seem to be very sandy. When I followed a car the amount of stuff coming out the back was incredible. What that does is two things: one, it makes the driver pay the price if he goes a bit off line, which is good because it favours ability, but it is also makes people not want to take the risk in overtaking. Sand on your tyre takes a good lap to be cleared out.

And so it proved. It was largely a risk-avoidance race with drivers clearly sticking very closely to a single driving "line," conspicuously steering clear of the rest of the track - and often running into problems when they didn't. Grains of sand influencing a sporting spectacle and, as The Times Online concluded, "Whoever wins the inaugural Abu Dhabi Grand Prix on Sunday will be fêted in a nation that can afford to buy its heroes — but the victorious driver might feel his name is not written in history, but in the sand."

But if the sport was less than inspiring, the setting made up for it. This was the inaugural race at Abu Dhabi's latest example of construction extravagance. Ras Island, just down the coast from the preposterous artificial island developments of Dubai, was but a sandy expanse a mere 30 months ago (see the Google Earth image at left of the image at the head of this post). It hardly seems to have been a natural island, but rather 25 square kilometers of coastal desert, sandbanks, and sabhka (salt flats) carved out and isolated from the mainland by manmade waterways. After several tens of billions of dollars, and the efforts of tens of thousands of workers, things have changed. The image below is of the hotel complex across the track (as night falls, as it did for the Grand Prix, the whole thing glows in a succession of changing colours) and at the right in the image at the top is the way the whole place will look when finished.

 

The strange red object in the centre of the header image is "Ferrari World," the largest indoor theme park on the planet, "like a megalomaniac’s pleasure dome" in the words of the NYT. Yas Island will boast  20 hotels, 3 theme parks, a "Super Regional mall", golf courses, several marinas, and commercial and residential developments. You can read the full specs at the developer's website, but in case you don't here's a sampling of the exuberance on this "island of dreams":

There will be a Super Regional Mall that will house famous retail brands from
around the world in over 500 stores and 4 floors including lifestyle, fashion &
boutiques.
• There will also be room for a complete town centre concept, contained in a
number of adjacent buildings and built under a 88,100m2 roof
• The Yas Mall will have one of the largest free standing roofs in the world,
showcasing 296,000m2 of the world’s best retail space
• Adjoining the Yas Mall will be will be Abu Dhabi’s first Multi-purpose Retail
Park (100,000m2)
• Three major department stores will be accommodated.
• A large hypermarket covering an area of 17,000 m2

 What I have not been able to determine is how much concrete goes into this monster (one hotel used 45,000 cubic metres of it, the racetrack 225,000) or, indeed, where all the sand came from for that concrete; presumably, as in neighbouring Dubai, local sources of non-desert sand were used (the windblown stuff being too rounded and smooth for good concrete), and the local natural sand budgets consequently profoundly changed. But it's not just the natural sand budgets. Although sand prices around the world have fallen during the economic crisis, they peaked in 2007 at more than $40 per ton, and sand supplies were becoming difficult. The Economist recently ran an article (pleasingly titled "The hourglass effect") that began:

“LOOKING for sea-sand for reclamation project in Singapore. Prompt reply is greatly appreciated.” Many such pleas can be found on Alibaba.com, a popular Chinese trading-website. Malaysia banned sand exports as long ago as 1997. Indonesia followed suit in 2007 on environmental and, some say, political grounds. Ever since, it has become harder for Singapore to secure supplies for its booming construction industry and sea-fill plans.

Singapore has turned to Cambodia and then Vietnam for its sand, but both have now banned exports. It seems that Myanmar may be the replacement supplier, so I will see my favourite material propping up, through, of course, western contractors, a loathsome dictatorship. The need is clear for a more widespread development and use of advanced forms of concrete that not only use less sand, but also can be manufactured without the associated emissions. And considering that every man, woman, and child on the planet "consumes" forty times their own weight in concrete every year, the sooner the better.

And finally, still on sand budgets and still in the news, today's Guardian newspaper carries a piece titled "Tide turns again for Cancún in shifting sands row." The 800,000 cubic metres of sand that were used to replace beaches washed away by Hurricane Wilma a few years ago lasted only a few months, and the current project is only the latest in a series of failed attempts at beach nourishment.

A huge project to replenish eroded beaches in Mexico's main Caribbean coastal resorts, including Cancún, has been suspended after legal action by environmentalists.

Campaigners claim the $75m (£45m) plan – involving taking 6.2m cubic metres from a sandbank just off Cozumel island, 50 miles from Cancún, to hotel beaches – is based on incomplete assessments.

Critics say dredging the sandbank will alter currents and damage ecosystems, including coral reefs and breeding grounds for species such as the queen conch. They also fear Cozumel will become more vulnerable to hurricanes. "It's absurd. We understand it is necessary to fill out the beaches but it needs to be done without sacrificing other places," said Alejandra Serrano of the Mexican Centre for Environmental Law.

But Rodrigo de la Pena, president of the Hotel Association, criticised the delay: "We cannot sell ourselves as a place of sun and sand, if we don't have the sand."

Alejandra Serrano is right - it's absurd. But then so many things are, including much of what I've just written about .....

Manchester Science Festival

Next monday, the 26th, I'll be giving a talk at the Manchester Science Festival (Manchester UK, that is). A year or so ago, on British TV, there was a series of programmes with titles such as "Ten things you didn't know about volcanoes," "Ten things you didn't know about earthquakes," and so on. It seemed to me that not only were these titles rather patronising to the viewer, but that the programmes, although entertaining, failed to convey the excitement of science. After all, what keeps scientists enthusiastic, and what keeps science going, is what WE don't know. And there's an awful lot in that category.

So I decided to talk about how even an apparently humble material has its mysteries, and illustrates a variety of areas of scientific enquiry. The talk is, of course, intended to entertain, and so I'll be stirring the occasional frivolity and magic trick into the mix, but think about it: granular physics, coastal and desert dynamics, meanders, meiofauna, Mars, Titan...... My challenge (as always) is what to leave out. The talk will be at Blackwells bookshop, 6.30 pm. And Jan Zalasiewicz, whose provocative book, The Earth After Us I've written about earlier, will be talking on tuesday evening. 

Earth Science Week - sand and the nine big ideas

 

This is Earth Science Week, in the US at least. It's an idea that deserves, through globalisation or international intellectual contagion, to be celebrated worldwide. Sponsored by the American Geological Institute, and supported by a consortium of earth science organisations, it is also underpinned by the Earth Science Literacy Initiative funded by the National Science Foundation:

The Earth Science Literacy Initiative (ESLI).... has gathered and codified the underlying understandings of Earth sciences into a succinct document that will have broad-reaching applications in both public and private arenas. It establishes the “Big Ideas” and supporting concepts that all Americans should know about Earth sciences. The resulting Earth Science Literacy framework will also become part of the foundation, along with similar documents from the Oceans, Atmospheres and Climate communities, of a larger geoscience Earth Systems Literacy effort.

The primary outcome of the Earth Science Literacy Initiative is a community-based document that clearly and succinctly states the underlying principles and ideas of Earth science across a wide variety of research fields that are funded through the NSF-EAR program, including Geobiology and Low-Temperature Geochemistry, Geomorphology and Land-Use Dynamics, Geophysics, Hydrologic Sciences, Petrology and Geochemistry, Sedimentary Geology and Paleobiology, and Tectonics.

It goes (I hope) without saying that the fundamentals of Earth Science Literacy are principles that all human inhabitants of our planet should be familiar with - a utopian aspiration perhaps, but it would arguably make our planet a better place. The fundamentals have been distilled into nine "Big Ideas," each with its own set of supporting concepts, and the summary and guide can be downloaded from the website as a pdf. And it's a compelling document; an Earth Science literate person is defined as someone who

• understands the fundamental concepts of Earth’s many systems

• knows how to find and assess scientifically credible information about Earth

• communicates about Earth science in a meaningful way

• is able to make informed and responsible decisions regarding Earth and its resources

As I read through the nine Big Ideas (and being the arenophile that I am), I was struck by the way in which the stories that sand has to tell can form a theme, a narrative thread that weaves through each of the ideas, illustrating and developing. So below are the nine Big Ideas, each one illustrated by sand, together with links to posts on Through the Sandglass that are but a minor sampling of those stories. This is, on the one hand, something of an indulgence, a sort of retrospective of this blog so far, but, on the other hand, I would like to think that it might be an inspiration, a different, and entertaining, route to Earth Science Literacy. 

1. Earth scientists use repeatable observations and testable ideas to understand our planet. And a large variety of scientific principles are harnessed to reveal the complexities of the earth system. 

Whether it's in the field or the laboratory, as providing vital testaments to the Earth's history or revelations on surface processes and the bizarre behaviours of granular materials, sand and sandstones provide crucial evidence and insights. Sedimentary structures allow reconstruction of past environments and events, a typical integration of fundamental physics, engineering, mathematics, and fieldwork led to our first understanding of how deserts work, and analysis, through granular physics, of the underlying laws of natural systems sheds light on a wide range of phenomena. 

2. Earth is 4.6 billion years old. And throughout its history enormous changes have occurred through gradual and catastrophic processes.

The age of our planet is determined from meteorites and lunar materials, but the oldest bits and pieces formed on the earth itself are sand grains - zircons from Australia dating back more than 4.2 billion years. And zircon grains have many tales to tell of our planet's tumultuous history of change. And then the entire sedimentary record of the earth's history, incomplete and variable as it is, represents the fundamental ledgers of the saga.  

3. Earth is a complex system of interacting rock, water, air, and life.

Whether inorganic in origin, formed from the disintegration of rocks under the assault of atmospheric weathering, or biogenic, formed from shell and other organic debris, sand tells the stories of chemical and hydrologic cycles, energy and material transfer, and mass balances of natural materials. The size of sand grains influences the appearance of the entire planet.

4. Earth is continuously changing.

Sand, by its very nature, is perhaps the most dynamic of natural materials, and geological change on a human timescale is daily illustrated by shape-shifting bodies of sand on our coasts, in our oceans, and in our rivers and deserts. 

5. Earth is the water planet.

And sand is a ubiquitous participant in the great game that water plays in earth processes. Go to the beach and watch the game in action in miniature, or wonder at the huge scale of marine sand transport, the complexity of coastal processes, or the changing dynamics of rivers (with or without human interference).

6. Life evolves on a dynamic earth and continuously modifies earth.

Evolution is a fact. Sand preserves the evidence and can drive ongoing evolution today. Microorganisms are the most widespread, abundant, and diverse group of organisms on the planet, and many of them spend their lives in the company of sand grains. Our beaches host biodiversity possibly greater than that of the rain forest; bacteria turn sand into sandstone, and countless critters build their homes from sand. And then there are the provocative ideas on the interactions between organic and inorganic evolution.

7. Humans depend on earth for resources.

And sand represents a huge resource in countless ways. Electronics, concrete, and precious minerals are but a few examples of sand as a resource - and think how much of our water and hydrocarbons reside in the pore spaces between the grains of sand and sandstone reservoirs.

8. Natural hazards pose risks to humans.

The residents of New Orleans or Samoa whose houses were filled with sand following hurricane Katrina and the recent tsunamis are only too aware of this. The good folk of the Red River Valley, desperately filling sandbags during the floods of earlier this year know all about natural hazards. Desert towns around the world face the threat of moving sand every day. But careful earth science investigation of past catastrophes - for example, tsunami forensics - can help us understand these risks and prepare for future events.  

9. Humans significantly alter the earth.

Boy, do we ever. Earth Science Week this year is dedicated to climate change, but there are endless other examples of our footprint. We dramatically change sediment budgets, altering our coasts on a daily basis; we completely disrupt the natural dynamics of rivers and their sediment transport role. And we do these things often for the most trivial and short-term reasons.

Sand contributes to the economic stimulus

As a young kid, I was blessed with six great-aunts, who lived together in two groups of three, one group in Nottingham and the other in the East End of London. Visiting either somewhat eccentric group was always a treat for me, their rambling old houses filled with strange (but still memorable) aromas, exotic Victorian decoration, and sundry mysteries (including the outside toilets). The London group consisted of two spinsters and a widow plus cats and, generally, a lodger priest whom I tended to avoid. I loved visiting, particularly if my great-aunt Grace (my favourite) had made bread pudding, still the best I have ever tasted. But a culinary mystery, and a genuine piece of kitchen magic, was when she preserved eggs. These were still the post-war days when eggs were precious, and, in any case, old habits die hard. The eggs were immersed in this strange substance, which began as a viscous fluid, diluted for the purpose. "It's waterglass, dear," my great-aunt would explain; this struck me as being very descriptive, since it looked like liquid glass, but little did I realise how accurate the name was.

Waterglass is sodium silicate, or, more strictly, sodium metasilicate, Na₂SiO₃, a chemical that easily absorbs water, starting off in my Great-Aunt's kitchen as a powder, and hydrating into a viscous fluid and then a true liquid. It seems that it penetrated the shell of an egg, sealing off the porosity and thereby preventing access by bacteria; eggs preserved this way could be kept for months. Waterglass showed up later in my life in various guises, including as an  sealant for various leaking bits of my early cars - it was particularly effective for a hole in the exhaust pipe, the heat of which would solidify a patch soaked in sodium silicate into a hard seal. The irony today is that sodium silicate is hitting the headlines not as a means of mending your car, but of completely crippling it. As a recent USGS news item reported:

The Nitty Gritty of Cash for Clunkers

The government-run “Cash for Clunkers” did much more than just stimulate the economy and raise awareness of carbon emissions. It also caused demand for a little known and little used mineral compound called sodium silicate. The program required that buyers of clunkers immediately kill the engine of the car — a task most efficiently done by running the engine with sodium silicate. When a vehicle runs for a few minutes with this compound in place of engine oil, the engine seizes, and it cannot be reused. The other parts of the vehicles, however, can be recycled.

The "Cash for Clunkers" project has caused a massive demand for an obscure mineral. As the Wall Street Journal reported a few days ago, under the headline "The Killer App for Clunkers Breathes Fresh Life into 'Liquid Glass'," the "designated agent of death for cars" suddenly became a highly sought-after commodity. One chemical supplier

ordered enormous supplies and purchased prime space on Google, so that his company popped up in searches for sodium silicate. Last week, he sold 4,600 gallons of it, and the rush is continuing. "We're working 16 hour days, and we've got friends and family helping out filling orders."

So where does all this magic, lethal, mineral come from? As the USGS reports, "Sodium silicate, the only soluble silica compound, is made by fusing two industrial minerals, high-purity silica sand with soda ash." Sand to the rescue of the global economy!

"Soda ash" is sodium carbonate, the naturally occurring form of which is the mineral natron. And so we come back to glass - "the stone that flows." The satisfying story that Pliny the Elder tells of the origin of glass is, sadly, apocryphal, but it's entertaining and illustrative of the process. He describes, in his Natural History, how Phoenician traders with a cargo of natron, perhaps from the desert lakes of the Sahara, had put in for the night on the eastern Mediterranean coast. Unable to find adequate rocks to support their cooking pots over the fire, they resorted to using some blocks of their cargo. Whatever their dinner recipe was, they had unwittingly assembled the ingredients for glass: the soda lowered the melting point of the beach sand, and out of the fire flowed streams of translucent liquid. It's a nice fairy-tale, but with an important point: to melt sand on its own requires temperatures in excess of 1,600°C (2,900°F), far beyond the capability of traditional wood-burning furnaces. The melting point has to be lowered to a practicable temperature, and this is where the natron plays its critical part in the story. Soda has a much lower melting point than sand and acts as a flux, an additive that makes silica sand meltable at realistically achievable temperatures.

But of course what is being made here is sodium silicate - waterglass, a product soluble in water, which is hardly desirable in making a wine glass or a window. To stabilize the glass, calcium in the form of powdered limestone has to be added, and it is entirely possible that this was first discovered by accident through using silica sand that also contained fragments of seashells. The resulting concoction is soda-lime glass, the everyday kind of glass that has been used for the last three thousand years.

Sodium silicate, while it is a somewhat obscure chemical, does, nevertheless, continue to be used in a number of different ways. It's still used as an adhesive and sealant, in treatments for timber, concrete, and water, and as a fire protection. Perhaps its most important use today is in the manufacture of synthetic zeolites, clever minerals that have a whole host of uses. It's also used in Magic Rocks. Although that name hadn't been yet coined when I was a kid, this was the other incarnation of sodium silicate that I encountered. In the days when chemistry sets really were chemistry sets, with ingredients capable of causing real domestic havoc and incurring real maternal wrath, one of the more benign but common chemicals provided was waterglass. With this, and some compounds of different metals, a "chemical garden" could be created. Put a layer of sand at the bottom of a glass container, add waterglass dissolved in water, and then chunks (the magic rocks) of different metal compounds, generally nitrates or chlorides of manganese, cobalt, copper, iron, and watch your garden grow. The metals combine with the waterglass to form insoluble metal silicates that precipitate and grow upwards to form exotic plant-like structures. The colour depends on the metal, just as the colour of glass depends on the metal added. The phenomenon was discovered in the 17th century, when waterglass was known as "oil of sand" and played a common role in alchemy. It would seem that Sir Isaac Newton, in his experiments in the transition between alchemy and "chymistry," created magic gardens in oil of sand, the organic appearance of the structures confirming the old alchemical idea that metals have a kind of life and can "vegetate".

It's sort of fun where a simple story of disabling clunker engines can get to - my great-aunt Grace would be pleased.

Intercalations and a virtual book tour

 

I've just finished reading David Williams' recently published book, Stories in Stone: Travels Through Urban Geology, a title following on from David's eponymous blog and website. It's a great read that satisfies the two primary criteria for non-fiction: informative and entertaining, and there will be more on the book later (see below). As I was reading it, I was struck by the echoes and relationships with my own book, and the archaic word intercalations for some reason struck me as appropriate. It's not archaic in the sense of being no longer in use, but its appearances tend to be rare and rarified - including in geology. I remember standing in front of outcrops and scribbling in my field notebook "blocky sandstones, 10-15 cms, occasional thin shale/siltstone intercalations." I could, in reality, just as well have written "interbeds," since all I was describing was regularly alternating layers of sandstone and shale; but "intercalations" lent gravitas to the description. It's an interesting word - the "inter" part is obvious, but it surprised me to discover that the "calation" is from the same Latin origin as "calendar," and, in turn, "call." The Latin verb intercalare meant to proclaim, and reflects the calling in of accounts on the first day of the month - calends - to be recorded in the calendar, or account book. Amongst other applications, the word has come to be used for inserting extra days into the calendar, as in "February has an intercalary day every four years." Various scientific disciplines have appropriated the word "intercalate" as an alternative for the more prosaic "insert" or "interleave" - molecules can be intercalated with each other, as can various biological items.

So, as I was reading David's book, the image came to me of the connections between Stories in Stone and Sand as interwoven, interleaved, intercalated. It's interesting to me that both of us regard story as critical, and David weaves fascinating stories around the variety of building stones that he has chosen (surely a difficult culling task). But furthermore, I suppose in part because I am attuned to any occurrence of the word "sand" - an obsession which, literally, is satisfied on a daily basis by even a cursory scan of the media, - I was conscious of the recurring role of sand in David's stories. Not just the obvious ones of sandstone as building material - the Brownstones of New York (which featured also in my book) - but in the sense that even the great limestone and marble building stones (including the Carrara), began life as sand banks of biogenic materials and ooliths in balmy tropical seas, that it's intercalated layers of storm-deposited sand that made the extraction of blocks of Florida's coquina stone easier, that, from ancient Egyptian to relatively recent times, sand has provided the abrasive for cutting even the toughest building stones, and that sand can be an unwelcome intruder, a spoiler of the finest quality slate. Geological tales - the discovery of dinosaur footprints by Pliny Moody in the Massachusetts sandstone that told the story of separating continents, James Hutton's revolutionary insights at Siccar Point - feature in both books: it just seems that there are some episodes, some stories, that provide unparalleled access to our understanding of our planet.

The stone stories of David's book will be further explored over the next few weeks by virtue of a blogging innovation - a virtual book tour. The schedule of events is listed at http://stories-in-stone.blogspot.com/2009/08/virtual-book-tour-of-stories-in-stone.html, starting with Brian and Clastic Detritus - http://clasticdetritus.com/2009/08/14/friday-field-foto-89-triassic-sandstones-in-brooklyn-ny/. I am very much looking forward to David's visit to Through the Sandglass at the end of this month.  

[California turbidites used in the image at the head of this blog courtesy Earth Science World Image Bank http://www.earthscienceworld.org/images, Copyright © Marli Miller, University of Oregon]

USGS beach health advice - but let's hear it for meiofauna

The US Geological Survey newsroom has just put out an advisory on the importance of washing your hands after playing in the sand on the beach:

By washing your hands after digging in beach sand, you could greatly reduce your risk of ingesting bacteria that could make you sick. In new research, scientists have determined that, although beach sand is a potential source of bacteria and viruses, hand rinsing may effectively reduce exposure to microbes that cause gastrointestinal illnesses.

Yes, indeed, my mother - and mothers in general - were right: "wash your hands!".

Beach pollution is a significant problem, but things could be a lot worse.

I learned many things in the course of writing the book, but perhaps the most extraordinary revelation was the staggering diversity of minute creatures that creatively and tenaciously make their livelihoods in the miniature worlds between the grains of sand on our beaches. The general term for this microscopic zoo is meiofauna, the "lesser animals." Representatives are shown in the image at the head of this post (photos by M.D. Hooge), and it is their world that Rachel Carson was referring to in The Edge of the Sea, when she wrote "Walking back across the flats of that Georgia beach, I was always aware that I was treading on the thin rooftops of an underground city." And the meiofauna do a heroic job of keeping our beaches clean. Here are a couple of extracts from Sand on the interstitial jungle:

In the great hierarchy of living things on our planet, it is generally accepted that, at the head, there are five kingdoms, one of which—animalia—contains all multicelled animals. Within each kingdom are a number of phyla: all mammals, birds, reptiles, amphibians, and fish belong to the phylum chordata. Depending on which biologist you speak to, between thirty-six and forty total phyla are recognized on our planet. Rainforests, our flagships of biodiversity, are known to contain sixteen phyla. The spaces in between sand grains are home to twenty-two.
..........................................................................................................

The dark, watery world beneath the surface of the intertidal zone of most beaches is home to many kinds of bacteria—and a jungle of other minute creatures. Silica, or quartz-based sands, are the most hospitable, since the calcium carbonate in sands composed of shell fragments makes the water too alkaline for many creatures to flourish. Pick up a handful of wet quartz sand on the beach and you are holding a miniature zoo with thousands of inhabitants. Some of these were first observed by Antony van Leeuwenhoek as he peered down his microscope at sand grains and his animalcules, but we owe our understanding of the incredible diversity and importance of this community to the work of Robert Higgins, who since the 1960s has devoted his life to identifying and describing its members. Now retired from the Smithsonian Institution, Higgins is the pioneer of work on meiofauna (“lesser animals”), creatures whose giants are 1 millimeter long; he continues to contribute to the identification of new species, which crop up at the rate of a dozen or so every year. In a 2001 symposium that paid tribute to his discoveries, Higgins modestly described his work as “how the ‘lesser-knowns’ became better-known.”

Life between the sand grains is not an easy one. The grains move and settle under the pressure of the waves and the incessant flushing of the tides, water occasionally drains out completely, and the ecosystem contains a variety of predators. Life has had to adapt, and it has done so in strange and extraordinary ways that reflect an intimacy with the behavior of granular materials. Many of these creatures have armored or padded bodies designed to withstand abrasion by moving sand grains; their shape is often flat or elongated to enable squeezing between the grains; and they have developed a variety of ways of attaching themselves, using glue or suction, to individual sand grains, clinging on for dear life. Rotifers, nematodes, mystacocarids, tardigrades, gastrotrichs, turbellarians, and kinorhynchs—it’s tempting to view these little animals as rejoicing in their exotic names. Tardigrades, which live in both marine water and freshwater, can’t swim, so hanging on to a sand grain is vital; some use mechanical suction toes, some claws, some both. A gastrotrich can glue and unglue itself in an instant. A kinorhynch is ungainly, described by Higgins as an umbrella in a canister, but it moves effectively, if slowly, exploring one sand grain at a time. Rotifers, so named because they look like rotating hairy wheels, are represented by 2,500 different species, most of which are freshwater dwellers. Tardigrades have the remarkable ability to suspend operations if the water disappears, remaining dormant and dehydrated for a hundred years, only to spring back to life when rewetted. They seem to do this by replacing the water in their cells with sugar, which renders them immune to freezing and radiation, a talent that is of considerable interest in the worlds of medicine and extraterrestrial biology.

In the entire living world, only three new phyla were identified in the twentieth century, and one of them came from the strange world of meiofauna. In the 1970s, Reinhardt Kristensen, a professor at the University of Copenhagen and an old student of Higgins, showed him a collection of creatures from the coast of Brittany that he could not identify. “Oh,” responded Higgins, “I have one of those too.” The animals fit with no known group of living things, and it took several years of meticulous collaborative work to define the character of the creature as a new phylum. It looks rather like a classical amphora with snakes emerging from it, and they named it loricifera, “corset-bearing,” reflecting the appearance of the rings that sheathe the animal. More than seventy species have now been identified, but we know next to nothing about their behavior, since, sadly, they die before reaching the laboratory. One remarkable thing we do know is that loricifera have the smallest cells of any known animal.

Inevitably, the community of organisms growing on or living in sand has its own name: psammon. Among the psammon are psammophiles (or arenophiles, if you prefer Latin to Greek), psammobionts, and psammoxenes. The names are weighty, but the members of the community are not; what they are is wondrous. Most of us don’t know they exist, but we should be grateful for them. Without meiofauna, the sands of our beaches and lakeshores would be stinking, toxic places, with organic debris rotting unconsumed and dangerous bacteria rampant. The microscopic creatures of the meiofauna feed off this debris: they keep our beaches clean.

[for more information on these fascinating creatures, see the site of the network of 94 European marine institutes, http://www.marbef.org/wiki/Meiofauna_of_Sandy_Beaches, the International Association of Meiobenthologists at http://www.meiofauna.org/, http://discovermagazine.com/1995/apr/lifeonagrainofsa491, and http://whyfiles.org/022critters/meiofauna.html, the latter particularly on Higgins.]