Through The Sandglass

Sunday sand: Halloween and a cruise

 
I'm in the US - Philadelphia to be exact - and it's October 31st, so, HAPPY SANDY HALLOWEEN!

The reason that I'm over here is that tomorrow I must go to New York and board the Queen Mary 2.Then anchors away (although I'm sure that doesn't apply to today's maritime technology) and eastward ho, back to Southampton. During the course of the week's cruise I will regale the passengers with three talks on sand, yes, up to three hours of me telling stories of all things arenaceous. This is thanks to an arrangement between Oxford University Press and Cunard, a programme titled "Science at Sea." My main concern is that the casino might prove more seductive than sand, but I shall carry on regardless ("stay calm and carry on" being the current catchphrase in the UK, channeling Winston Churchill when times get tough).

I'm not sure how posting over the coming week will work, but I will hope to do something (I'm assured that, of course, Wi-Fi is available on board). In the meantime, here's the graphic I put together for the talks, a thematic journey from one plate, one set of cultures, to another.

Benoit Mandelbrot: a personal story

Over twenty years ago, I read James Gleick’s Chaos: Making a New Science and was instantly gripped by the exotic world of strange attractors, Cantor sets, Julia sets – and, of course, the celebrated Mandelbrot set. This was simple mathematics revealing deep and unexpected wonders – exotic, yes, but immediately resonant of the world around us. You could see nature’s mathematics just by looking out the window. And, of course, a significant component of nature’s design style is fractal, and it was Benoit Mandelbrot who revealed this to us. Mandelbrot died on the 14th October and there has been, appropriately, an outpouring of praise  for this truly extraordinary man and his brilliant work. I won’t attempt to add to this, but I will tell a story: the story of when I met Benoit Mandelbrot.

Twenty years ago, I was far from alone in my enthusiasm for fractals – the concept is powerful and the mathematics shows up in so many, often unexpected, places. Like many others, I became somewhat carried away with my enthusiasm, seeking fractal geometries in every data set. I departed from what seemed to me a rather boring topic that I had been invited to address at a Financial Times Conference in London: having briefly prognosed the outlook for oil and gas exploration in southeast Asia, I launched into a (reasonably well documented) lesson in how the diviners of oil prices should seek help from fractal analysis in their hopeless task. This was not unreasonable, since Mandelbrot had demonstrated how other commodity prices demonstrate fractal characteristics, but a standing ovation was conspicuous by its absence and I was never invited back.

 Fractals, however, show up in many aspects of geology – bed thicknesses in sedimentary piles, grain sizes, the spaces between sand grains (vital for the porosity and permeability of a sandstone reservoir), and characteristics of faults and fractures, to name but a few. At that time, I was working in international exploration for “big oil,” the US company ARCO, to be specific, subsumed not long after into – oh dear – BP (but I had left by then. One of the great pleasures of that job was that the company had wisely – or, more probably, through an accident of real estate management – located my group in the same building as the research labs. The stuff that went on in those labs was fascinating, and I spent a lot of time keeping track of what they were up to and staying in touch with some of the really smart people working there. It was one of my friends in the labs who called me up one day, and told me that Mandelbrot was coming in – would I like to join the discussion? The question was one of those where the Pope and bears figure in the answer.  

There was, sensibly, little in the way of a formal agenda for the meeting, the intention being to show Mandelbrot some of the problems vexing the research group and open up the space to see how this remarkable mind viewed the problem – the discussion was wide-ranging and certainly not focussed on fractals. I will have to admit that I found the prospect somewhat intimidating – after all, this was the Benoit Mandelbrot. But the reality was a delight, a gentle, thoughtful, man who put effort into listening before he would begin to ask questions. And, of course, it was in his questions that the value lay, the possibility of insight; the science we were talking about was often not familiar to him, and so his questions were intriguing – and challenging. The conversation moved on to oil and gas explorationists think about the earth’s subsurface, and the term “play” came up. “What do you mean by that?” asked Mandelbrot, and all the heads in the room turned to me. So, there I was, explaining something to Benoit Mandelbrot....

Now, a “play” is a concept that helps the evaluation of how likely it is that, below the earth’s surface, an area, or a given group of rocks will have the components of the geological conspiracy that is necessary to create oil and gas accumulations. There are a number of key ingredients, perhaps the most important being a source rock – most commonly a shale, a rock that contains sufficient organic material to brew hydrocarbons; no source rock, no play. And then there’s the maturity of those source rocks, how well they have been cooked in the earth’s kitchen; immature source rocks, no play. Add in all the other components – a plumbing system for oil and gas to flow through, then something that stops that flow – a trap – and something sufficiently porous to contain the trapped oil and gas – a reservoir – and you have a means of describing a play. Each of the components can be assigned a risk of whether or not it is present, and the chances of it working, and so the further work needed to define these components can be identified and different plays compared. All this was not easy to explain, but Mandelbrot’s questions along the way were not only illuminating in making me think about what I was really trying to describe, but they were thought-provoking in general. I don’t, today, remember many of the details, but I certainly remember the experience, the rare opportunity to be challenged by the thinking of a brilliant individual.

It’s interesting how, in the meantime, the power of fractal geometry has been increasingly recognised, and how more and more examples have been identified. I was just reading a recent New Scientist article on “The chaos theory of evolution” that commented that “the history of life is fractal. Take away the labelling from any portion of the tree of life and we cannot tell at which scale we are looking. This self-similarity also indicates that evolutionary change is a process of continual splitting of the branches of the tree.” But we still haven’t figured out exactly what to do with fractals. They have revolutionised computer graphics, but their deeper meaning continues to elude us. However, the idea of scale invariance and self-similarity in nature’s designs continues to provoke and stimulate. Take, for example, this work by the artist Alison Cornyn; titled Sand and Moon: “The top image is a portrait of two grains of Coney Island sand. Below it is a NASA image of Phobos, one of the moons of Mars.” This is part of Cornyn’s larger project, Sand Portraits, of which probably more later. But for now I just wanted to mark my gratitude to Benoit Mandelbrot for an unforgettable and intellectually enriching experience.

 

[There’s a great video from February this year of Mandelbrot talking at a TED conference on “Fractals and the art of roughness” here (the site includes a number of other videos). Amongst many obituaries, the one from The Economist is a good starting point. For a description of her work by Alison Cornyn, and full credits for the images, see http://www.mcsweeneys.net/books/everythingthatrises.contest35.html. The photograph of desert boulders comes from a 1933 newspaper report of one of Ralph Bagnold’s expeditions.]

Sunday sand: more forams

Walking on a beach in Bali is, more often than not, a delightful experience, even idyllic. But occasionally it can be a challenge to the balance, a sensation of walking on ball-bearings. This problem arises from the composition of the sand – it is essentially ball-bearings, dominated by myriads of minute spherical shells of foraminifera. The samples above were sent to me by another old arenokleptomaniac friend with whom I worked for many years.

Forams are remarkable creatures (I wrote of some Indian ones a while ago), thriving in more or less every marine environment on earth, including deep sea hot hydrothermal vents. They have a long history, going back hundreds of millions of years: hundreds of thousands of species represent that record. Today there are around 4000 living species, although that is only an estimate: judging from the astonishing results of the international collaboration of the Census of Marine Life in which 6000 new species of marine organisms are reported, we actually have no idea how many varieties of foraminifera there are. They come in all shapes and sizes, some with shells made of just one chamber, others with multiple chambers, constructed in spirals and seemingly endless other designs. The University of California at Berkeley has a great foram site, and the most common forms of this wonderful spectrum of shell design are described there as follows:

unilocular -- a single chamber

uniserial -- chambers added in a single linear series

biserial -- chambers added in a double linear series

triserial -- chambers added in a triple linear series

planispiral -- chambers added in a coil within a single plane. The center of the coil is called the umbilicus. The coil may be either involute (only the chambers of the last coil visible) or evolute (all chambers visible).

trochospiral -- chambers added in a coil that forms a spire like a snail shell. The side on which all chambers are visible (evolute) is called the spiral side. On the other side only the final coil is visible (involute) and this is called the umbilical side.

milioline -- chambers arranged in a series where each chamber extends the length of the test, and each successive chamber is placed at an angle of up to 180 degrees from the previous one.

fusuline -- a planispiral coil which is elongated along the axis of coiling. Typically each chamber is subdivided by a complex set of internal partitions.

tubular -- a simple hollow tube.

arborescent -- an erect, branching series of tubes. These forms may live attached to a solid surface or "rooted" in sediment.

irregular -- without any definite arrangement of the chambers. These forms usually live attached to a solid surface.

Most of the shells are built of calcium carbonate, but, as we shall see, some forams use other construction methods. Their dazzling variety was recorded in detail by the first great oceanographic research voyage, that of the Challenger in the 1870s. As I have described, the entire set of reports of the expedition is available, wonderfully, online, including the lengthy chapter devoted to forams, illustrated by 115 plates, each one showing a dozen or so specimens. Perhaps the most dramatic illustration is this one of globigerina, a planktonic foram:  

But I mentioned that some forams build their shells differently – they are the deliciously named agglutinated forams that simply use whatever is available as fragmentary material to glue together a shell. So, when we find these forams as in a sediment, they are sand grains made out of sand grains. And, as with other creatures that build with sand, the glue they use is of considerable interest to medical science.

 

 

 

 

The plates from the Challenger report include several of agglutinated forams, including, inevitably using the Greek for sand, psammophaera.     





And, coming back to the continuing saga of the discovery of new species, it was reported earlier this year that “tiny single-celled creatures called foraminifera living at extreme depths of more than ten kilometres build their homes using material that sinks down from near the ocean surface.” Agglutinated forams happily living in the so-called “hadal” depths of the ocean. Where were these critters found? In the Challenger Deep.

 

[The Challenger reports are on line thanks to Dr. David C. Bossard, prepared from original documents in the library holdings of Dartmouth College, Hanover New Hampshire.]

The Max Planck Institute for Dynamics and Self-Organisation

 
Here’s an entertaining thought experiment: what’s the difference between sand grains immersed in water and in air? The answer: absolutely nothing, except for the fluid – as Professor Stephan Herminghaus and his colleagues in Göttingen will tell you, they can both be treated as dry granular materials. There are no capillary forces and no liquid bridges between the grains in either case, and so the behaviour is essentially equivalent – and dramatically different from slightly wet sand - “soft matter” - where the capillary forces and bridges dominate the material’s character and allow, for example, the building of sandcastles.

I have just returned from an couple of days in Göttingen that included a visit to the Max Planck Institute for Dynamics and Self-Organization, a world-leading centre in research into the bizarre behaviours of granular materials, and of which Stephan is the Managing Director. But first, a brief explanation of why I was in Göttingen in the first place. Every year, the city hosts the Göttinger Literaturherbst, the autumn literary festival and, remarkably, I was invited to give a talk as part of the science strand of the event. The talk was last Saturday night and I was overwhelmed by the number of people who saw this as the way to spend a weekend evening. I was also more than overwhelmed by the venue. The Paulinerkirche, the church of Saints Peter and Paul, was built in 1304 and now forms part of the historical building compound of Göttingen State and University Library; it is a stunningly beautiful building:

 
At the far end of this picture is an exhibit case. And in there that evening was this:

 

Yes, the original 1610 edition of Galileo’s Sidereus Nuncius, the first scientific publication on observations through a telescope, describing the Milky Way, the moons of Jupiter, our Moon, and much more. This was almost too much. Göttingen is already awe-inspiring as you walk (extremely humbly) in the footsteps of Carl Friedrich Gauss, Ludwig Prandtl, Max Planck, Arthur Schopenhauer, Jon von Neumann, Max Born, David Hilbert, Werner Heisenberg, Bismarck, and the Brothers Grimm – to simply start the list. But I calmed myself down in the kind hands of Stephan Herminghaus as the moderator for the evening and launched into my German introduction. Not speaking German at all (except for greetings, thanks, and beer-ordering), and feeling the usual Anglophone guilt at the fluency of non-native-speakers, I had prepared some words of thanks and apology and employed my German brother-in-law to translate. After a lengthy phone audition with him, I then phoneticised the script and practiced diligently. The warm reception from the audience made it clear that this was going to be an enjoyable evening. This being a literary festival, I had prepared a talk that roamed from James Joyce to Australian aboriginal art via Rachel Carson, Jorges Luis Borges, and bacillus pasteurii – plus, of course, the wonders of granular materials. It was a great evening – a warm and enthusiastic audience, many questions, totally enjoyable.

The whole thing culminated in a book-signing session (always gratifying) and it was then that I met Matthias Schröter and Sibylle Nägle, who work in the Dynamics of Complex Fluids group at the Max Planck Institute. They asked if I would like a tour of the research labs the following day; I was obviously - and thankfully - unsuccessful at hiding my enthusiasm and protesting that the following day was Sunday and perhaps they had better things to do – we arranged to meet at the facility at 9.30 the following morning.

Now, much as I have been fascinated by the wonders of granular materials and much as I have written and talked about them, I had, until then, never had the privilege of actually seeing the work going on. We walked in and it was immediately seductive – it actually has that indefinable lab aroma. And it was, as is also typical, simple, almost garage-like, but, at the same time occasionally slightly chaotic; and, in every room, were very sophisticated pieces of kit designed, together with home-made apparatus, to investigate the complex behaviours of remarkably simple (apparently) materials. Here’s a vibrator (designed originally for shaking automobiles as part of the testing procedure, so this is a serious vibrator) that generates a model of the dynamics of a granular gas. The granular material in this case is comprised of rubber balls, a blur of frenzied activity that can be frozen momentarily by the camera flash.

 
One of the group’s primary quests is to better define the elusive but vital phase diagram for granular materials (see Matthias’s webpage on the topic) – Matthias patiently gave me a “granular phase diagrams for dummies” introduction to what he was working on:

 
Many of the research projects are simple but extremely clever. For example, while documenting the kinematic journeys of individual granular particles remains a challenge, the incredibly rapid changes in groups of moving particles can be tracked using the speckle patterns produced when the light from a laser responds to those changes – using a high-speed camera capable of seeing things going on far too rapidly for the human eye:

And then there is this, extremely impressive toy:

 
Borrowed from medical technology, this is an X-ray computed tomography unit: incredibly detailed 3-D imaging allows examination of granular packing structures, segregation, grain-to-grain interactions and much more. When we visited, the machine was in the middle of a run, but Matthias showed us movies of some initial trails that were amazing – including one of a sequence of images that allowed a student to decipher the combination of his bicycle lock that he had forgotten.

This is but a brief sampling of the kind of work that is going on in Stephan Herminghaus’s labs – my thanks again to all involved for making the weekend so memorable.

I’ll end with a couple of notes: first, in an environment under which UK scientific research is under threat of decimation, it was refreshing to find a country in which the critical contribution of fundamental science is still recognised and in which the necessary funding is available. Second, one of the questions I was asked after the talk was that, while it seems that granular materials research concentrates on using spherical grains of one sort or another, surely different shapes, different angularities are important? The answer is, of course, yes, nature rarely deals with perfect spheres, but even understanding the behaviours of perfect spheres remains a huge challenge and we can barely begin to deal with odd shapes – the exciting challenge of deceptively simple things.

And, finally, the superb buildings of old Göttingen are dominated by the beautiful hues and textures of the classic European Triassic - the Bunter Sandstone. Cross-bedded, of course:

[There’s a short film on YouTube of the work of Stephan and his colleagues – it’s in German, but the combined imagery of kids and cutting-edge physics is delightful in its own right. The image of sand-charged waves at the head of this post is from the DHD Multimedia gallery, Damon Hart-Davis]

Sunday sand: Brazilian gems

 
Sometimes, a sand just strikes me as beautiful in its own right – yes, of course it has geological stories to tell, but  (although perhaps I shouldn’t admit this) they seem somehow secondary. And that’s the case with these Brazilian gems.

I was fortunate, when I was writing the book, to make contact with Loes Modderman, a Dutch enthusiast for many things, among them sand. I came across a series of stunning images on her website and Loes went out of her way to help me use one of them in the book. Not only was my use of her photo entirely free, but this was the start of an ongoing correspondence; furthermore, she kick-started my collection of sands by sending me a substantial sampling from her vast collection. And this sand was one of them. It’s from a beach at Camburi on the coast of Brazil, north of Rio; it’s a tourist resort, set in the midst of highly urbanised area on the estuary of several rivers that drain the old interior of the continent. And these grains of quartz sand are old, torn from the Pre-Cambrian granites and other rocks that form the ancient core of South America. They are survivors – and, as such, seem full of character.

These are the kind of images that are stunning in their own right; but I can’t help playing around with Photoshop to see what happens…

 

Earth Science Week and Earth Science Literacy

 
It’s Earth Science Week again, stimulated and coordinated by the AGI:

Since October 1998, the American Geological Institute has organized this national and international event to help the public gain a better understanding and appreciation for the Earth Sciences and to encourage stewardship of the Earth. This year's Earth Science Week will be held from October 10-16 and will celebrate the theme "Exploring Energy."

This time last year I connected this with the Earth Science Literacy Initiative, again an American program funded by the National Science Foundation, and I put together, inevitably, a discussion of how sand illustrates the “Big Ideas” documented by that initiative. I would like to think that, today, one year on, it would be possible to document progress in awareness and literacy, but I fear that it’s not. If anything, on both sides of the Atlantic, it’s got worse. The events surrounding “climategate” and its repercussions have profoundly damaged trust in science, in the UK research funding is about to be dismembered, anti-intellectualism is a vote-catcher in the bizarre corners of the US midterm elections, and news headlines continue to rely on fear and over-simplification. Yet the means by which the voices of science and scientists can create a meaningful riposte to all this remain elusive. And yet who could dispute the statement from the Earth Science Literacy initiative that:

An Earth-science-literate public, informed by current and accurate scientific understanding of Earth, is critical to the promotion of good stewardship, sound policy, and international cooperation. Earth science education is important for individuals of all ages, backgrounds, and nationalities.

While both of these projects are inspired by institutions in the US and directed in the first instance to an American audience, they are both of international importance: simply replace “American” with “global” in their content. And that content is excellent. Here are the “Big Ideas” (again, in the interests of generating a little momentum here and there):

Big Idea 1. Earth scientists use repeatable observations and testable ideas to understand and explain our planet.

Big Idea 2. Earth is 4.6 billion years old.

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

Big Idea 4. Earth is continuously changing.

Big Idea 5. Earth is the water planet.

Big Idea 6. Life evolves on a dynamic Earth and continuously modifies Earth.

Big Idea 7. Humans depend on Earth for resources.

Big Idea 8. Natural hazards pose risks to humans.

And, since I certainly couldn’t put it any better, here’s an extract from the “Background and Motivation” section of the Earth Science Literacy document:

Defining a set of essential ideas that a literate American should know about the geosciences is a critical national need in an information-rich age characterized by a rapidly changing planet and numerous resource challenges. Critical decisions involving Earth science are continuously made within the political and educational realms, with significant impacts on all American citizens. In today’s world, it is no longer sufficient for scientific communities to assume that simply doing a good job of carrying out cutting edge research is sufficient. The research community simply must do a better job of making sure that its scientific discoveries do not get buried in libraries or on the Internet, but make it into mainstream circles. The research community must do a better job of helping the public understand the most important concepts emerging from geoscience research. However, understanding scientific discoveries requires a science-literate population. The Earth sciences literacy document that has been produced here will help accomplish that goal, and can help inform those who will make future decisions involving governmental legislation and educational science standards.

With the development of the Internet, our society has very rapidly gone from being information-poor to information-overwhelmed in the area of science (and many other areas as well). As a result, the need for a set of BIaSCs (“Big Ideas” and Supporting Concepts) has become paramount. There is an overwhelming amount of information available, but not necessarily any sense of how to navigate through it or determine what is most important. Someone trying to find out about an Earth science topic (a lawyer, engineer, museum director, textbook writer, legislator, etc.) could easily be overwhelmed by the amount of information available. A prioritization of essential ideas, carried out by the scientific communities, would provide the basis and framework that would help people navigate through the rapidly expanding amount of scientific information…

It is quite possible that, from the perspective of future civilizations, the 21^st century will be defined by three things: climate change, water availability, and energy resources. These three are not independent, of course, and the fate of humanity will rest upon how they are addressed over the next 100 years. Importantly, in the context of the current proposal, all three are deeply rooted in the areas of Earth science. Many important political, legal and ethical decisions are being made related to these issues that already severely affect the lives of all Americans. The lack of clear, concise and comprehensive community-driven guidelines puts all Americans at risk of bad decisions made either through either ignorance or self-interest. For example, the resistance within certain spheres to accept the relevance and validity of global climate change for as long as it did caused our country significant embarrassment at an international level, and severely delayed international attempts to address the matter.

This is especially important in areas of Earth science, which are becoming increasingly relevant as human populations increase and natural resources dwindle. More than a third of all land not covered by ice is now used for producing food for humans (agriculture or the grazing of livestock). This land use must be planned with maximum understanding of Earth science, and the BIaSCs we have created here will become part of a process that help guide the education and policy-making needed to allow it to happen.

The Earth Science Week and Literacy sites are full of excellent further resources – for example, the SEED online toolkit, and the Ocean, Atmospheric Science, and Climate Literacy Networks.  

For the header for this post, I used the stunning image of our planet recently released by NASA. Rather than the traditional view with its emphasis on the continents, this image reveals the truth of the matter – the “Blue Marble” really is dominantly a water planet. The wording that goes along with the image is:

Viewed from space, the most striking feature of our planet is the water. In both liquid and frozen form, it covers 75% of the Earth’s surface. It fills the sky with clouds. Water is practically everywhere on Earth, from inside the rocky crust to inside our cells.

This detailed, photo-like view of Earth is based largely on observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. It is one of many images of our watery world featured in a new story examining water in all of its forms and functions. Here is an excerpt:

“In all, the Earth’s water content is about 1.39 billion cubic kilometers (331 million cubic miles), with the bulk of it, about 96.5%, being in the global oceans. As for the rest, approximately 1.7% is stored in the polar icecaps, glaciers, and permanent snow, and another 1.7% is stored in groundwater, lakes, rivers, streams, and soil.

Only a thousandth of 1% of the water on Earth exists as water vapor in the atmosphere. Despite its small amount, this water vapor has a huge influence on the planet. Water vapor is a powerful greenhouse gas, and it is a major driver of the Earth’s weather and climate as it travels around the globe, transporting heat with it.

For human needs, the amount of freshwater for drinking and agriculture is particularly important. Freshwater exists in lakes, rivers, groundwater, and frozen as snow and ice. Estimates of groundwater are particularly difficult to make, and they vary widely. Groundwater may constitute anywhere from approximately 22 to 30% of fresh water, with ice accounting for most of the remaining 78 to 70%.”

And, on that note, I read two recent headlines: “Water cycle goes bust as the world gets warmer,” and “Expect More Floods as Global Water Cycle Speeds Up.” One predicts droughts and the other floods (all as a result of global warming). They are undoubtedly both right, in different ways and for different reasons; changes in the “global” water cycle (if there is such a thing and if we were genuinely able to measure it) result from profoundly complex interactions and feedbacks amongst a host of variables, and manifest themselves in very different ways at different places on the earth’s surface. Can we please look at these two pieces of research in this context – and learn from them through the spectacles of Earth Science Literacy? 

 

[On the topic of science reporting in the media, Martin Robbins, on the UK Guardian newspaper site, recently wrote a great piece “This is a news website article about a scientific paper.” It’s very funny – but it’s also depressing in its accuracy: enjoy it and see if you can read a science report in the media in the same way ever again. And yesterday he described two completely conflicting interpretations of recent research on the sun's behaviour....]

 

 

 

Sunday sand: glass beaches

  

The phrase “glass sand” would normally make you think of ultra-pure sand resources used in glass-making, such as the sands of Fontainebleau. But I was intrigued by the link that Jules provided in his comment on last Sunday’s sand, a complete inversion of this meaning: sand made from glass. The link was to the Earth Science Picture of the Day (EPOD) for the 7th October that showed a beach on the Hawaiian island of Kauai where much of the sand is composed of glass fragments. That image is reproduced above, and here’s a superb photo of this sand by Tom Amon:

  



Set in an industrial area of the island, this beach records the reworking of a landfill (in reality, it seems, a euphemism for people simply tossing rubbish into the sea), closed long ago. Huge numbers of glass bottles had been disposed of amongst the waste; these were subsequently smashed, fragmented, pulverised (or that wonderful word, comminuted), rounded, frosted and polished by the ocean. The sand of “Glass Beach” is not exclusively composed of these grains, and the glass fragments are not exclusively sand-sized (although time will tell), but it still comes as a surprise that walking on broken glass is so painless. 

The larger pebbles of “sea glass” on Kauai are treasured by collectors of the stuff (vitramarinophiles?) – and this location is by no means unique. There’s another “Glass Beach” near Fort Bragg in California. Its origin is the same: for years the locals simply threw their garbage over the cliffs into the sea, and they threw everything, including cars. In 1967 the area was closed to such activities and is now part of a State Park, the sands riddled with worn glass fragments:

And there are other “glass beaches” around the world, some of them, not surprisingly, around the island of Murano, in the Venice lagoon, home of fine glass-making for more than 700 years; when failures occur, the objects on the left end up as the objects on the right:

 

But surely, one might ask, if nature can do this so effectively and rapidly, why don’t we? Why not intentionally manufacture sand out of glass as an effective and useful way of recycling? The answer is that we do – to some extent. Broward County, Florida, faces the Atlantic Ocean and includes the metropolis of Fort Lauderdale; the beaches are famous and vital to the local economy – but they have a habit of disappearing under the influence of natural processes and human meddling. For years, millions of tons of sand have been pumped from offshore banks to “nourish” the beaches, at huge costs – and the extent of the operations has now meant that the sand supplies are running out and the offshore environment completely changed. So, also for years, the authorities of Broward County have been supporting a project to evaluate the use of sand made from glass in replenishing their beaches – something already done on the beaches of New Zealand’s Lake Hood and on the Dutch Caribbean Island of Curacao. There’s a good article on this here. The plan would never be to use only recycled glass for beach nourishment, the volumes required being so huge, but as a contribution it would seem like an obvious thing to do – as Commissioner Ilene Lieberman comments, "It's basically sand, so you're just putting it back to its natural state." But nothing is ever that simple. Recycled glass sand is an inert material and therefore, it would seem, environmentally benign and as close to its natural equivalent as you could get; part of the Broward County research has demonstrated this. But no, environmental concerns remain, and, anyway, “The county also wants to do more study on using crushed glass, mixed with natural sand, to boost the beaches. That proposal looked promising … but there's no company in Florida that supplies it, so the cost to study it more is prohibitive for now.” These quotes come from a report from last month of the “controversial sand bypass plans” which would excavate a huge offshore area to trap sand that would then be available for beach nourishment. Of course, this sand would then not be available to Fort Lauderdale, down the coast, and thus the Fort Lauderdale authorities are not impressed.

However, sand made from recycled glass is being used to some extent in concretes (interestingly coloured ones) and other standard aggregate appplications, as well as some sports surfaces, golf bunkers (sand traps) and so on – but we remain less efficient than the processes that create nature’s “glass beaches.”

 

[There’s a good piece on Glass Beaches here, and on Kauai specifically here. For the Broward County project, see last month’s report in the Sun Sentinel, a good article by Patti Roth, and one of the Project Reports. Fort Bragg beach photos from Microimaging and Jef Poskanzer, Creative Commons license.]

Wellington invades France - sand makes success possible

 

Since I’m still in France for a few days, this historical story seems particularly à propos, or even de rigueur. The setting is the border between Spain and France at the Atlantic end of the Pyrenees, the time the early 19th century, and the context the Peninsular War. Napoleon’s armies had marched across Spain and invaded Portugal in 1807; Spain, hitherto an ally of France, together with Portugal and Britain, fought back and thus began this long phase of the Napoleonic Wars. The campaign in Spain, together with Napoleon’s ill-fated invasion of Russia, debilitated the French forces and, by 1813, the allied forces under the command of Arthur Wellesley, 1st Duke of Wellington, had pushed northward and were poised at the French border.

That border ran along the Bidassoa River that flows out of the Pyrenees and reaches the Atlantic in a broad tidal estuary in Basque country between the towns of Hondarribia on the Spanish side, and Hendaye on the French. As can be seen in the Google Earth images below, the towns and infrastructure along the river have, not surprisingly, been much altered over the last two hundred years – the airport at Hondarribia was clearly not available to Wellington, and the sand banks on either side of the river mouth have built up as a result of the construction of breakwaters. But the basic geography remains, and the border still runs along the river.

The river is broken up by channel bars, sand islands. One of these, L'île des Faisans (the Island of Pheasants), has long been of historic importance as the location of political negotiations between France and Spain, prisoner exchanges, and bridal swaps. In order to preserve it as an international stage, the island is stabilised by stone buttresses to prevent it being washed away. In 1615, an exchange of young royal women for marriage into the opposite royal families took place on the island. But an even more significant event is recorded by the island’s alternative name, L’île de la Conférence. For three months in 1659 the island was the setting for the conference between France and Spain that negotiated and finalised the border between the two countries, the Treaty of the Pyrenees. Today, it remains a condominium, in international law a political territory over which two or more sovereign powers formally agree to share equally dominium (in the sense of sovereignty) and exercise their rights jointly, without dividing it up into 'national' zones (Wikipedia). Every six months the island changes between being French and being Spanish – it’s the smallest condo in the world.

But back to the Peninsular War. By September 1813, the allied forces had pushed the French back to their side of the Bidassoa, where their commander, Marshal General of France Nicolas Jean-de-Dieu Soult, set up his line of defence. Given the expanse of the river and its estuary, Soult felt that the Atlantic end of his line was secure; he concentrated his forces further east, expecting an attack across the mountains, leaving only a modest contingent around the towns of Hendaye and Béhobie – where the bridge was destroyed.

Wellington arrived on the southern bank of the river near the town of Hondarribia, and, it would seem, sent his intelligence officers and linguistic experts out among the local population. They determined that, in Basque, hondar means sand, and ibi means ford. At specific very low tides, sand banks merge from the river and make crossing possible – and such a tide would occur early on the 7th October. It would appear that Soult’s local linguistic and geographical intelligence had not determined this.

Wellington’s engineers constructed turf walls along the river which successfully hid his artillery, Lord Aylmer’s Brigade, Major General Hay’s 5th Division, together with Portuguese and other allied troops. When, at 7.25 a.m. on the 7th October, Wellington’s forces surged across across the river, the French were completely surprised and overwhelmed. William Napier, the military historian who participated in the action, would later write that the allied troops “took the sands in two columns…appearing in the distance like huge sullen snakes winding across the heavy sands.” More allied troops crossed the river near Béhobie and joined forces with the 5th Division; the high ground on the French side of the river fell to the allies and Wellington had his foothold in France for the first time. He consolidated and pushed on – the allies entered Paris on the 30th March, 1814, and Napoleon abdicated on the 6th April.  

The Napoleonic Wars would, of course, start up again, ending only with Waterloo in 1815; however, the sand-enabled invasion of France across the Bidassoa was a key event in the ultimate downfall of Napoleon – hooray for sand!

[I first came across this story via More French Leaves, entertaining glimpses of expat life in the south of France, by Christopher Campbell-Howes. The print of the Battle of Bidassoa used at the head of this post is from Martial Achievements of Great Britain and her Allies from 1799 to 1815, published in 1831, and discovered, appropriately, at http://www.armchairgeneral.com/]

Sunday sand: the movie!

 

Last year, after my travels along the Atlantic Coast of France, I described the stunning and dynamic miniature landscapes sculpted in the sands of Cap Ferret at low tide. At the time, I experimented with my newly acquired movie camera to record some of these scenes and processes, but it’s only recently that I have devoted some time to learning the editing software, rendering, and uploading to the web. The first result is below. The quartz-dominated sand contains a significant proportion of dark, heavy grains of iron minerals, and these play a starring role in revealing the patterns of sedimentary transport, the brushwork that highlights the designs.

So, grab some popcorn and sit back. See sediment transport in action! Travel down miniature canyons! Revel in the evolution of ripples! Witness the conflict between erosion and deposition! And the finale looks over the Bay of Arcachon to the great sand dune of Pyla, Europe's largest - but more of that in the sequel.....

[This movie is posted here at only a moderate resolution - the original is significantly more detailed.]