Through The Sandglass

Street cred (a belated contribution to “dune week”)

 
So, I ask myself, how could this blog possibly miss the “dune week” celebration on the geoblogosphere, an arenaceous festival if ever there was one? The great thing about asking yourself is that a credible answer should be forthcoming – feeble though it may be in this instance: “distracted, pressures of work, general indolence… but better late than never, eh?” I am not convinced, but, anyway, offer this:

In the great deserts of the world, the sand seas made up of the long, towering edifices of seif dunes, elongate, shape-shifting mountainous ribbons of sand, named after the Arabic word for “sword,” are invariably characterised by intervening “streets.” These are the lanes between the long dunes, mysteriously swept free of sand, covered instead in pebbles and cobbles – as in my example from Egypt’s Western Desert, above. There are, at least, two explanations for these “streets”:

1. Ralph Bagnold, the man who figured out how deserts work, offered a clear model, based on physics, experiment, and meticulous science, that showed how the saltation of sand grains driven by the wind was much more energetic over pebbles (bouncing) than over a sand surface (splashing). This led to a removal of sand from a rocky surface and, inevitably, to its self-accumulation into dunes.

2. The Walmajarri people of Australia’s Great Sandy desert believe that their streets (below) were swept clean by mythical snakes journeying westward.

 
Please don’t choose between these explanations – both are equally acceptable.

 

[For some great dune reading, see Dana Hunter’s post and round-up of the geoblogosphere’s eponymous week.]

Abrasive Sunday Sand

 
All in all, it’s been an abrasive week. No, I’m not referring to my day job, but rather an emerging theme that started with my last post on the stories of three indefatigable women and a mystery Gobi sand. So far, there have been two very interesting responses to my question of what the mineral content of this “special sand” might be that made it so prized for polishing jade (and I’m also following up on other suggestions): Howard Allen helpfully defines some constraining criteria in terms of hardness and density (we must be dealing with something heavy enough to form a placer deposit, and hard enough – but not too hard – to polish a tough material like jade). Richard Bready – knowledgeable and stimulating as always – points to the work of a researcher at The British Museum whom I should contact, and sources that mention corundum, quartz, and garnet.

Earlier in the week, I heard from Siim Sepp, a graduate student of geology at the University of Tartu in Estonia, who alerted me to his areno-blog, Sandatlas, which he has been expanding into a wide-ranging and informative source for a variety of geo-topics. Browsing around Siim’s site, I was struck by one of the images in his gallery, above. This stunning sand is from the area of the Emerald Creek garnet district in the panhandle of Idaho, where garnets from sand- to golf ball-size occur in placer deposits that, organised by the Forest Service, can be visited by the public for a “mine your own garnets” day out. Garnets have been used since antiquity as both gemstones and abrasives, and the latter continues to be a widespread application today; Emerald Creek, in addition to being a Forest Service recreational area, is still one of the leading sources of industrial garnets in North America, producing a range of product sizes for everything from serious sand-blasting to fine polishing via water-jet cutting.

There are quite a few different “species” of the mineral group collectively referred to as garnet; they are all silicate minerals (strictly, nesosilicates or orthosilicates), but their composition (and colour) varies, with different sites within the crystal structure being occupied by iron, magnesium, calcium, aluminium, and chromium. Nevertheless, they all belong to a single group because they all have the same crystal form – the crystals are isometric, their internal structural symmetry being that of a cube. In garnets, these highly symmetrical internal building blocks most commonly organise themselves into the overall shape of a dodecahedron, but other related shapes can also form. The combination of colour and symmetry produces some truly stunning crystals, such as this one from Emerald Creek, the big one being 2.5 centimetres across (image from Exceptional Minerals):

 
One particular form, the star garnet, is the State Gem of Idaho; these extremely rare specimens are examples of asterism, the appearance of a luminous star shape as a result of tiny fibrous crystals of the mineral rutile (titanium dioxide) being included in the structure:

Garnets have a torrid geological history, born at high temperatures and pressures deep in the earth’s crustal kitchen, and, as a result, showing up at the surface in metamorphic, or, less commonly, igneous rocks. The garnets of the Emerald Creek district originate from sediments deposited around 1.5 billion years ago, buried, cooked, and rudely ejected back to the surface; weathering has liberated the tough garnet crystals to be concentrated in the stream placer deposits, but the original hard rock has also been extensively mined for not only garnets but a wide variety of minerals and metals.

So, not a solution yet to the Gobi mystery, but, for me at least, an interesting detour from the daily grind.

Extraordinary women–and a Gobi sand question

 
For one reason or another, I have been reading The Gobi Desert by Mildred Cable and Francesca French. In the history of exploration and enquiry into far-flung parts, it’s easy to overlook that regiment of indefatigable women – particularly Victorian - who played extraordinary roles. Perhaps the most celebrated was, of course, Gertrude Bell, whose middle-eastern exploits changed politics and history. But in China, in the first couple of decades of the last century, there were three women, Mildred, Francesca, and the latter’s sister, Eva (Evangeline), who documented the landscapes and culture of that part of the world through quite remarkable travels. Yes, they were missionaries, but they pursued their goals with linguistic skills and a deep cultural sensitivity that resulted in accounts that are distinctly and fascinatingly different from the typical travel writing of the times and have become classics. And the classic of the classics is their description of their thirteen years in the Gobi, “following trade-routes, tracing faint caravan tracks, searching out innumerable by-paths and exploring the most hidden oases. ... Five times we traversed the whole length of the desert, and in the process we had become part of its life."

The story begins as they set out from the fort at what is today called Jiayuguan, the westernmost bastion of the Great Wall. Leaving the western gate, they passed a great mound of earth whose role was to keep out the evil spirits of the desert, and a stone tablet on which were inscribed the forbidding words “Earth’s Greatest Barrier.” Following the Silk Road westwards, they stopped at isolated and insular oases – Shachow, “City of Sands,” Shamen, “Gates of Sand.” These even before they reached the Taklamakan Desert proper.

But one of the things that intrigues me is the following account from their overnight stay in Huei-huei-pu, the “Moslem Tomb Halt,” whose location today I have yet to figure out. While wandering around the village, Mildred stopped at the local shop, where

There was something different here, however, for, in addition to the dull stock of the oasis shopkeeper, this man had a variety of articles made from a fine-grained, light-grey stone which was found near at hand. These were slabs on which to rub down the hard sticks of Chinese ink, and little pots to hold water with which to moisten them. The chief demand, however, was for small pieces to be used as whetstones for knives, razors or scissors, and many a carter passing that way added a hone to his small outfit of traveller’s necessities.

Having made some purchases, Mildred sat down and chatted with the shopkeeper about this and that, but then

I turned to go, and just as I was leaving, I noticed on his counter a jar of coarse grey sand. Taking some of it in my hand, I rubbed it between my fingers testing the quality of the grains, and as I did so I felt there was something unusual about it. “What do you keep sand for?” I asked. “Is there not enough of it by the roadside?”

“This is special sand, Lady,” he said. “It comes from near here but is not found elsewhere in the Gobi.It is so heavy that the wind does not blow it about, and it is the only sand which can be used for one process in the polishing of jade.Though it is hard enough to use even on jade, yet it never scratches the surface. It is very highly valued, and jade polishers send here to get it.”

So there’s my question – does anyone have an idea as to exactly what this highly valued sand might be?

Sand bottle houses

 
Once in a while, out of curiosity, I just go to Google News and enter “sand.” More often than not, among the reports of the latest exploits of one of the Junior High School basketball teams from Sand County, Nebraska, are a couple of items of interest, not to say surprises. Here’s one from a recent report from BBC News:

Nigeria's plastic bottle house

By Sam Olukoya BBC Africa, Yelwa

Nigeria's first house built from discarded plastic bottles is proving a tourist attraction in the village of Yelwa. Hundreds of people - including government officials and traditional leaders - have been coming to see how the walls are built in the round architectural shape popular in northern Nigeria.The bottles, packed with sand, are placed on their side, one on top of the other and bound together with mud.

"I wanted to see this building for myself as I was surprised to hear it was built from plastic bottles," said Nuhu Dangote, a trader who travelled from the state capital, Kaduna, to see the house. "They were saying it in the market that it looks like magic, that you will be amazed when you see it, that is why I have come here to feed my eyes. The whole world should come and look at it."

The real beauty of the house is its outside wall as the round bottoms of the exposed bottles produce a lovely design. But for those behind the project, its environmental benefits are what are most important.

Twenty-five houses, which will be available to rent, are being built on this estate on land donated by a Greek businessman and environmentalist. Each house - with one bedroom, living room, bathroom, toilet and kitchen - uses an estimated 7,800 plastic bottles. This "bottle brick" technology started nine years ago in India, South and Central America, providing a cost-effective, environmentally-friendly alternative to conventional building bricks.

Yahaya Ahmed of Nigeria's Development Association for Renewable Energies, estimates that a bottle house will cost one third of what a similar house made of concrete and bricks would cost. It is also more durable.

"Compacted sand inside a bottle is nearly 20 times stronger than bricks," he says. "We are even intending to build a three-storey building." The bottle houses are also ideally suited to the hot Nigerian climate because the sand insulates them from the sun's heat, helping to keep room temperatures low. And because of the compact sand, they are bullet-proof - which may also prove another attraction in more insecure parts of the north.

A firm concrete foundation is laid to ensure that the structure is firm and stable - and the sand is sieved to make sure it is compact. "You need to sieve it to remove the stones otherwise it will not be nice and it would not be able to pass through the mouth of the bottle," explains Dolly Ugorchi, who has been trained in bottle house building. Bottles for the houses are mainly sourced from hotels and restaurants

Some have expressed concern about the amount of sand needed for the new houses. "My fear is that this building method will increase the demand for sand and even lead to an increase in the price of sand," says Mumuni Oladele, a mason in the southern city of Lagos. "At the moment people looking for sand to build houses dig everywhere to get the sand. You can imagine what will happen when the demand for sand goes up to build bottle houses."

According to market research company Zenith International, most water in Nigeria is sold in small plastic bags, but it says the bottled water market is growing - accounting for about 20-25% of official sales, the equivalent of up to 500m litres a year. This means discarded plastic bottles are actually sought after in Nigeria where they are often used for storage or by street vendors to sell produce like peanuts. The bottles for these houses are currently being sourced from hotels, restaurants, homes and foreign embassies.

The project is also hoping to help to remove children who do not go to school from their life on the streets.

"I don't want to be a beggar, I want to work and get paid - that is why I am doing this job," says 15-year-old Shehu Usman, who is working on the building site. "When I grow old I want to build myself a house with bottles," he says.

After the 25 houses have been completed, the next construction project for the Development Association for Renewable Energies will be a school on the estate, which street children like Shehu will be able to attend.

Children making money filling bottles may one day be able to attend a school to be built on the estate

Seems to me that this creative idea addresses all sorts of issues - but then, of course, I would think that.

[See also a report with some more details here.]

Sand continuum - a modelling breakthrough

It’s happened again – a topic that I touched on in my Milan talk shows up in a New Scientist report from earlier this year (I only just caught up with it). In the talk, I commented on the profound challenges of mathematically modelling and simulating such an apparently simple material as sand, and referred to the amount of effort and research that had to go in to the stunning special effects for the Sandman character in Spider-Man 3:

 
From wired.com (ignore the reference to “the molecular structure of sand”):

The secret to Spider-Man's success can be found in a single grain of sand. After all, it's not really Peter Parker in latex that makes this film franchise a billion-dollar box office hit. It's the villain, and this time around it's the Sandman, a shape-shifting computer-generated marvel made up of thousands of digitized grains of sand.

But making the villain wasn't easy (nor was it cheap). It all started with director Sam Raimi peering through a microscope to study the molecular structure of sand, and led to two-and-a-half years of visual-effects R&D and a crew of 30 special-effects technicians.

"I had people bring in 12 different kinds of sand -- this is where people think the movie industry is insane -- so I could look at it," says Raimi. "I saw California beach sand, Mojave desert sand. We ended up picking Arizona sand because it looks exactly like ground corncobs. The reason that's important is that when you bury people alive in hundreds and hundreds of pounds of sand, they'll be squished. You need something lightweight like corncobs, so air can get through and the actors and stuntmen won't be crushed."

Computer modelling of sand as individual grains, even with the power of today’s algorithms and processing capacity, is limited to tens of thousands, perhaps a hundred thousand, grains. But now a different approach has yielded impressive results, as reported under the title “CGI tricks: How to make a fake beach look real” in the New Scientist:

From explosions in a desert, to the trickle of an egg timer, animated scenes containing sand are notoriously hard to model. But now Rahul Narain and his team from the University of North Carolina at Chapel Hill have developed a new technique that should make computer animations look more realistic.

Since sand is made up of a collection of tiny grains, its appearance can vary greatly. "It can look like a solid pile you can stand on, to a flowing avalanche, or even a cloud of dust," says Narain. Much work has gone into modeling solids and fluids, but materials such as sand have received less attention, perhaps because of these unique properties. So far, the only way to simulate sand has been to model every grain as an individual object, which can be extremely costly in terms of computation time and memory.

Narain and his colleagues are taking a more holistic approach. They realised that although individual sand grains do move independently, in practice the grains tend to flow together more often than not. So it made sense to make the most of existing fluid-modeling techniques and model sand as one big continuous material.

"This 'continuum based approach' makes it possible to simulate sand in a much faster and more memory-efficient way without sacrificing much in the way of realistic behaviour," he says.

Their new model also includes algorithms to make sure it's simulated realistically in instances when sand behaves differently from liquids. They do this by taking into account the forces on the particles, such as friction. When tested with animated sand clouds forming in an explosion (see video above) the results proved to be true-to-life.

As well as being used in animated films and games, when the technique is refined further it could be used to model real life scenarios such as avalanches and explosions.

The video (from which the image at the top of this post is a screen-grab) is impressive, and can be found on youtube.

Sand, steam, and slowing down - serendipity in Milan

 
On the opening night of the AAPG International Conference in Milan, I was lucky enough to be invited for a guided tour of the Museo Nazionale della Scienza e della Tecnologia "Leonardo da Vinci," followed by dinner in the part of the museum that was once an old priory. It was an altogether enjoyable experience, and one that started off with one of those odd, random, and entertaining convergences. The first stop on our tour was the transport hall, a cavernous space filled with diverse means of locomotion, and we spent a while examining a serious piece of engineering in some detail – steam locomotive 691-022, built in 1914, and retired from the Milan to Bologna route. It of course caused nostalgic conversations amongst those of us of a certain age, the personal archives of sight, sound, and smell being stimulated and re-lived.

Towards the end of his description of this leviathan, our guide posed a question: “given the lack of friction between the wheels and the track, how was the monumental momentum of this locomotive countered when trying to bring the thing to a halt?” Rather modest brake shoes were observed, but it was agreed that they would be quite ineffectual since the whole thing would simply continue to slide. It was, inevitably, yours truly who felt compelled to shout out “sand!” The dome on the top of the boiler (visible in the photos above) was the sand box from which a pipe can be seen leading downwards to feed the sand onto the track. Of course, yours truly had failed to bring a camera for the occasion, but here’s a photo (courtesy of this website) of the same mechanism on a US locomotive of around the same vintage – the brake shoe is also clearly visible.

 Go to Wikipedia for the workings and components of a typical steam locomotive, and on the associated diagram, number 7 points out the sand dome (or sand box) and number 19 the sand pipe:

 
Look up “sand box” on Wikipedia and you will find the following:

A sandbox is a container on most locomotives and self propelled multiple units, or trams, (a type of train that runs on roads) that run on tramways and adhesion railways. The container holds sand, which can be dropped on to the rail to improve rail adhesion under very wet or steep conditions.

The sand may be delivered by gravity, by a steam-blast (steam locomotives) or by compressed air. Gravity sanding requires that the sand is dry so that it runs freely. Steam locomotives in the USA had a single sandbox, called a "sand dome" placed on top of the boiler where the rising heat helped to dry the sand. Even with this arrangement, sand pipes tended to clog, and by the 1880s, pneumatic sanding systems were being proposed. On diesel and electric locomotives and railcars, sandboxes were and are fitted close to the wheels so as to achieve the shortest possible length of delivery pipe. Depots may have a sand drier installed to warm and to dry the sand before it is used.

Our guide at the museum pointed out that that even this method of slowing down the train was hardly rapid – he told us that, from a speed of 120 km'/hr, it would take 100 kms to halt this train. We found this hard to believe – but he did point out that the distance from Milan to Bologna is 300kms.

 Now, this may seem like old technology, but it isn’t. The Wikipedia page on on the sand box includes the following image from a current UK train; note the reminder to “fill with dry sand only” – the assumption must be that the engineers responsible for maintaining this piece of kit have never built a sandcastle.

And, this is not the end of the story with respect to the value of arenaceous materials in the running of the railways. There is a standing joke here in the UK that originates from our illustrious rail network’s explanation of timetable disruptions by “the wrong kind of snow.” This is second in infamy to the  excuse of “leaves on the track.” It seems that autumnal shedding by the arboreal borders of much of this country’s rail system comes as something of a surprising inconvenience. But, yet again, sand comes to the rescue – through a material that I had never encountered before looking into the background for this post, a material that should be elevated to a prominent position in the arcane world of arenophilia: SANDITE!

 Please consult scot-rail.co.uk, “Scotland's online railway community,” to learn about methods that “are used to improve track conditions during the leaf fall season. This is done using a combination of water cannons and the application of sandite (a thick sand based paste that improves adhesion) to the rail surface.” Here's the delivery system - the tanks are, presumably, full of....sandite.

I never cease to be astonished…..

 

[Photos of the 691-022 from http://www.viaggivacanze.info/newsite/2011/02/milano-se-la-conosci%E2%80%A6-te-ne-innamori/ and http://commons.wikimedia.org/wiki/Category:FS_691; modern sand box image licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. Attribution: Roger W Haworth]

Tugu Beach: black sands on the move - and sand ladies

 
A week shipboard, tossed about in a small cabin, simple and basic, always creaking, and with the ever-present and heady aroma of diesel fumes (I won’t go into any details on the bathroom), was worth every minute for the experience and the spectacular places visited. But, by the time we returned to Bali (before the earthquake), a little landlubber luxury was definitely in order. This we attained superbly with a two-night stay at the Tugu Hotel in Canggu, blissfully removed from the manic hustle and traffic of Kuta and Denpasar. This kind of quintessentially Indonesian hotel, with its superb rooms, excellent food, beautiful grounds, and ever-attentive and friendly staff, comes, of course at a price – but a price that would nevertheless secure you not very much by way of a New York or London hotel, and a price that was worth every rupiah. And, while this blog is explicitly non-commercial, I can only recommend the Tugu as a gloriously different place to stay. As a flavour of what I mean, here, taken from our room (using the amazing “hand-held twilight” noise reduction function of my new toy), is the setting for our dinner the first night, next to the lotus pond, listening to the sound of the surf:

 
Which, inevitably, brings me to the shore. The surf was up and the surfers were out, but my focus was, of course, on the details of the beach. Here, the sand is a chromatically dramatic mix of glistening black volcanic grains (with occasional apple-green glints of the mineral olivine), glittering quartz, shell fragments, and our ubiquitous friends, the foraminifera.  

This palette, when used by the constant brush of the waves, yields delightful beach patterns. But, better still, where a stream comes down to the beach, and the heavier black volcanic grains behave differently from their lighter-weight colleagues (the placer effect of granular segregation), then things become quite spectacular.

 
This stream had carved out a miniature valley, revealing the old layers of storm sands that constantly avalanched down into the flow, a small-scale animated exhibit of earth surface processes.

And then the stream flow went to to work transporting and sorting the sand, sculpting it into ripples and small dunes, each structure graphically defined by the dark and light grains. A dynamic, shape-shifting system – and, being the areno-nerd that I am, I spent some time simply watching the ripples move, forming and re-forming, swirling and migrating. And here’s the movie:

   

Once carried down to the shore, the sand is then entered in a new transportation game, and becomes the massive cargo of unceasing wave action.

This being Indonesia, Tugu Beach is not simply a place for surfers and basking tourists – it is a hive of entrepreneurial (and undoubtedly illegal) activity. Sand is a valuable commodity here, and there was an industrious group of women (who, traditionally, do all the hard work in Bali), digging up sand, filling bags, and then taking them away by carrying them on their heads:

Every day in Indonesia brings some new experiences, some unexpected surprises – Tugu Beach proved to be a place where all of these were pleasurable.

 

Before and after Irene: spot the difference

 
I hardly need comment – before Irene, I wrote the “Nourish or Retreat?” post and then she proceeded to underscore the validity of the question. The USGS has, of course, some provocative images, a number of which I have reproduced here, and we all look forward to their more detailed analysis. I shall simply introduce a gallery of selected images with some pre-Irene words from Orrin Pilkey, guru emeritus of coastal processes, extracted from an article in the Los Angeles Times in which he described how sand supplied by large magnitude storms is essential to the survival of barrier islands:

The storm that is coming up the coast here is just what the islands need. We are going to see an awful lot of buildings destroyed and an awful lot of buildings damaged, and because it's so slow-moving, there are not only going to be high winds and big waves, but they are going to last a long time. A naturalist living on a barrier island knows that protecting your house is not a good thing, because protecting your house ends up destroying the beach.

 



I’ll end with a piece from Live Science, during Hurricane Ike back in 2008 and titled “Ike Underscores Foolishness of Building on Barrier Islands.” Note that Pilkey had a few words of wisdom here too:

"Barrier islands are exposed to the open ocean, and the waves and storm surges generated by hurricanes," said Bob Morton, a geologist at the U.S. Geological Survey's Center for Coastal and Watershed Studies in St. Petersburg, Fla. "As a storm makes landfall they're the ones that are going to receive the strongest winds and the highest wave actions."

Barrier islands like Galveston are particularly vulnerable to storm damage because they are made of sand, as opposed to the hard bedrock that underlies larger islands and the mainland. They also tend to have very low elevations, making it easy for water to wash over and submerge the island.

Many have questioned the wisdom of choosing to build on and develop barrier islands, given their risks.

"Every year there's reporting on the foolishness of building on barrier islands, but people are going to do it anyway," Morton told LiveScience. "We don't learn from the past. If you look at the barrier islands on the Mississippi coast in particular, after both Hurricane Camille in 1969, and Katrina, what did they do? They rebuilt. It's a perfect example of a coastal area that did get hit as bad as it can get, and they just go back and rebuild."

Barrier islands tend to be even riskier places to live than coastal areas, because they bear the brunt of any approaching storm impact.

"If you think about their location, they're basically lonely sentinels that serve as barriers for the mainland," said Clark Alexander, a marine geologist at Georgia's Skidaway Institute of Oceanography. "Basically you're in a vulnerable spot, because you're located where you get the first effects of anything coming in off the ocean."

Setting up residence in these vulnerable spots is particularly perilous.

"From a safety standpoint, it's silly," Alexander said. "Because the lifespan of a typical house is something like 60 years. But if you live on a barrier island, you can't guarantee you'll have land under your house in 60 years. It's trying to put something permanent in a place that’s very dynamic."

As a result of Hurricane Katrina, a number of barrier islands off the Mississippi coast were completely wiped off the map. Even when storms aren't enough to raze islands completely, barriers often suffer severe damage from storms.

The 1989 Hurricane Hugo wreaked massive havoc on Pawleys Island in South Carolina. Isles Dernieres off the coast of Louisiana was devastated by Hurricane Andrew in 1992. Often, after these storms, people move back and set themselves up for disaster again.

St. George Island on Apalachicola Bay off the Florida coast "has been washed away five or six or eight times and people just keep building back their houses," Alexander said.

For many people living on barrier islands, there is no amount of structural support that can ward off the worst.

"It's important to note that in the big storms, the category 4 or 5 hurricanes, it really doesn't matter how well-constructed your building is," said Orrin Pilkey, a professor emeritus of geology at Duke University, of homes on barrier islands. "And it doesn't matter whether you have a seawall or not. The chances are pretty good that if you have beachfront property, it's history."

Isn’t it about time we seriously addressed the question of whether further expenditure of money and resources in a futile and puny effort to battle natural processes is actually worth it?

But here we go again, shifting New Jersey sand around just days after Irene.

[Thanks to the USGS, AP, CNN and other sources for the images. For more on barrier islands, just put “barrier” into the search function on this blog.] 

Where does Singapore come from?

 
This may seem at first glance a stupid question, and the answer – Cambodia – even sillier. But it’s a fact. The tiny island nation of Singapore is home to a booming economy and the growth that goes along with it, not just commercial expansion, but physical. Singapore today is 120 square kilometres bigger than it was 50 years ago, and will grow by another 100 square kilometres over the next twenty years. And all these square kilometres can only be attained in one way – reclamation, otherwise known as filling in the sea. Filling in the sea with sand, huge volumes of sand. Singapore itself essentially has no sand, so it has to come, by one means or another, from elsewhere, and until a few years ago elsewhere was largely Indonesia. But, after the disappearance of several islands, Indonesia banned arenaceous exports. So where does Singapore go now? Cambodia – although note that Singapore does not disclose its sources. And is this all legal? Is it conducted after due environment impact assessment?  

I will simply leave the answers to these questions open, to be addressed by a recent article by Denis D. Gray of the Associated Press, that appeared in a number of publications recently, including the local English language newspaper here in Jakarta. I will, with further credits listed at the end of this post, simply take the liberty of reproducing this fascinating and depressing piece in its entirety.

 

Sand for sale; environment ravaged

By DENIS D. GRAY, Associated Press

Round a bend in Cambodia's Tatai River and the virtual silence of a tropical idyll turns suddenly into an industrial nightmare.

Lush jungle hills give way to a flotilla of dredgers operating 24 hours a day, scooping up sand and piling it onto ocean-bound barges. The churned-up waters and fuel discharges, villagers say, have decimated the fish so vital to their livelihoods. Riverbanks are beginning to collapse, and the din and pollution are killing a promising ecotourism industry.

What is bad news for the poor, remote Tatai community is great tidings for Singapore, the wealthy city-state that is expanding its territory by reclaiming land from the sea. Sand from nearby countries is the prime landfill and also essential building material for Singapore's spectacular skyline.

As more countries ban its export to curb environmental damage -- entire Indonesian islands have been all but wiped off the map -- suppliers to Singapore scour the region for what still can be obtained, legally or not. Cambodia, a poor country where corruption is rife and laws are often flouted, is now the No. 1 source.

Singapore is by no means the only nation taking part in what is a global harvest of sand from beaches, rivers and seabeds. Officials and environmentalists from China to Morocco have voiced concern and urged curbs. As construction booms in emerging economies and more sources dry up, however, exploitation of the remaining ones is likely to intensify.

Sand mining began anew in May on southwestern Tatai River, which empties into the ocean almost directly north of Singapore, across 1,300 kilometers (800 miles) of open water.

Despite denials by the main owner of sand mining rights in Koh Kong province, two Cambodian officials told The Associated Press that the sand is destined for the island nation.

Singapore will not say where its sand comes from; the Construction and Building Authority said it is not public information. The National Development Ministry said the state's infrastructure development company buys it from "a diverse range of approved sources."

The mining visible on the Tatai River clearly violates some of Cambodia's own legal restrictions, not to mention a recent government order to suspend it temporarily.

Vessels of a Vietnamese company were tracked by boat from about 10 kilometers (6 miles) upriver to the Gulf of Thailand, where nearly a dozen seagoing barges, tugs hovering around them, took on the sand.

The AZ Kunming Singapore, a 5,793-ton (5,255-metric ton) barge pulled by the AZ Orchid, was seen arriving empty from the open ocean, its tug flying a Singaporean flag. Both are registered with the Singapore government, which would not comment on the barge's cargo or destination.

Ships from several countries, including China, were spotted in sand-mining operations in Koh Kong province, where residents joked about going to Singapore and planting a Cambodian flag there.

The vessels included one from Winton Enterprises, a Hong Kong-registered group that was subcontracted to export sand to Singapore, according to Global Witness, a London-based environmental group that published a detailed account of the trade last year.

The report said that miners had penetrated protected mangrove, estuary and sea grass areas, breeding grounds for marine life along a coastline and hinterland harboring some of the country's last wilderness areas.

Cambodia's cabinet spokesman, Siphan Phay, who was investigating the issue in Koh Kong, appeared angry that the temporary halt order was being ignored. He described the activity as illegal mining destined for Singapore, a surprising statement given that government ministers awarded the concession.

A police officer in the economic crime division, who demanded anonymity given the issue's sensitivity, also said the sand is going to Singapore.

Ly Yong Phat, who holds the major concession in Koh Kong, has at times openly acknowledged the Singapore connection. But in a recent AP interview, amid tightening restrictions and mounting criticism, he said his company had not shipped sand to Singapore for more than a year because "our sand did not meet their standards."

The dredging, he added, was for local sale and to deepen river channels.

However, a Malaysian company, Benalec Holdings, said it was ready to tap up to 530,000 tons for a reclamation project in Singapore from several sources in Cambodia, including Ly Yong Phat's LYP Group.

Known as the "King of Koh Kong," Ly Yong Phat is one of Cambodia's biggest tycoons and a senator with close ties to Prime Minister Hun Sen. His holdings include hotels, a casino and agricultural plantations.

Land reclamation has enlarged Singapore by more than a fifth, and up to 100 square kilometers (nearly 40 square miles) more are slated for reclamation by 2030. What was once seabed is now Changi, among the world's finest airports, and more recently the Marina Bay complex, which includes a 2,560-room hotel and casino developed by Las Vegas Sands Corp.

Mountains of sand are needed for such fills. U.N. statistics show Singapore imported 14.6 million tons last year, ranking it among the world's top customers. Global Witness estimated that nearly 800,000 tons a year, worth some $248 million, were streaming to Singapore from Koh Kong alone.

The U.N. figures show that Cambodia supplied 25 percent of Singapore's imports in 2010, followed by Vietnam, Malaysia, Myanmar and the Philippines. With its secrecy and lax enforcement of environmental regulations, Myanmar could emerge as a major supplier.

The damage caused by sand extraction has spurred clampdowns on exports.

Malaysia imposed a ban in 1997, though the media there frequently report on massive smuggling into neighboring Singapore. Former Prime Minister Mahathir Mohamad complains that sand pirates are "digging Malaysia and giving her to other people."

An Indonesian ban came in 2007, following years of strained relations with Singapore over the sand on islands lying between the two countries. When miners finished with Nipah Island, reportedly all that was left was three or four palm trees protruding above the waterline. Environmental groups say smuggling is believed to be continuing.

Vietnam banned exports late last year.

Cambodia outlawed the export of sand from rivers in 2009 but allows it from some seabeds. Recently, some government officials said that rivers where seawater flowed into fresh water, replenishing sand naturally, were exempt.

Global Witness spokesman Oliver Courtney said the trade in Cambodia revealed a "mismatch between Singapore's reliance on questionably sourced sand and its position as a leader for sustainable development." The city-state prides itself on environmentally sound urban planning.

The dredging of the Tatai River began on May 17 "with a fury," creating a veritable traffic jam on the water, said Janet Newman, owner of the riverside Rainbow Lodge.

"Before you could see crab pots bobbing in the river everywhere and fishermen going out. Now there is nothing and nobody," the British woman said.

Chea Manith of the Nature Tourism Community of Tatai said 270 families along the river have seen an estimated 85 percent drop in catch of fish, crab and lobsters and were being forced to eke out a living from small garden plots. Tourists have all but vanished.

Armed with a petition, village leaders, tourism operators and a wildlife group met with Ly Yong Phat in early July. He appeared sympathetic, Newman said. He substantially reduced the dredging and has promised to stop altogether in October.

A subsequent letter from the Minister of Water Resources and Meteorology ordered the LYP group to halt operations temporarily on the Tatai, citing a breach of regulations. The letter was obtained by Cambodia's Phnom Penh Post newspaper, which made it available to the AP.

Hun Sen himself expressed concern over the mining in the river.

"We hoped that the prime minister's recent promise to review the impacts of the sand trade would lead to proper regulation of dredging operations," said Courtney of Global Witness. "Unfortunately, the pledge does not appear to have been followed up with meaningful action."

The mining has continued on the Tatai, and violations, such as dredging closer than 150 meters (165 yards) from riverbanks, were clearly evident.

The Post also obtained a Ministry of Industry, Mining and Energy letter extending LYP Group's concession in Koh Kong until Sept. 2012.

"We are just little people. We cannot do anything," Chea Manith said.

Newman sounded a more optimistic note. "It's my hope that the LYP Group will become sympathetic through this experience of having seen the reaction from people passionate about protecting their environment," she said. "It would be sad if they just went somewhere else to dump the same on others."

 

[Associated Press writers Sean Yoong in Kuala Lumpur, Malaysia; Alex Kennedy in Singapore; Jim Gomez in Manila, Philippines; Aye Aye Win in Yangon, Myanmar; and Sopheng Cheang in Phnom Penh, Cambodia, contributed to this report.]

Sunday sand: grains, chains, and biofilms

I guess that, if you wanted to write story for kids that illustrated the idea of the food chain, it could go something like this:

One evening, as the sun was setting over the beach, Walter the warty sea cucumber (although he preferred his grander name, Parastichopus parvimensis) was enjoying his usual dinner of sand. From in between the grains, he selected juicy, crunchy, and delicious meifoauna, delighting in the variety of flavours. But, unfortunately for Walter, among them, Nemo the nematode had just finished his dinner, and that had included some scrumptious morsels of Maribacter polysiphoniae, a very uncultured microbe. Now, Walter hated the taste of Maribacter polysiphoniae, and attempted to spit out his mouthful. But, being a warty sea cucumber, Walter couldn’t spit….

Well, perhaps there’s a good reason why I haven’t tried my hand at writing children’s stories. But I did write (unbelievably, just over two years ago) about meiofauna, the staggering diversity of miniature critters that live in the spaces between sand grains. Alarming as the idea of a zoo in your sandcastle might be, I commented how grateful we should be to the meiofauna, for they graze on bacteria and so keep our beaches clean. But what, exactly, are these bacteria? Well, at the head of this post is a portrait of a small sample on the surface of a sand grain. This extraordinary scanning electron microscope image comes from the work of Anthony D'Onofrio and his colleagues at the Antimicrobial Discovery Center of Northeastern University in Boston. This particular study has as its focus the bacterial life on intertidal sand grains from Canoe Beach in Nahant, Massachusetts, and, scrutiny at  successively higher magnifications reveals this (taken from the paper by D’Onofrio and others available online):

 
What we are looking at are incredible communities of bacteria – but these are not just any communities, since they have united together to cling to each grain as a biofilm, and biofilms are startling and mysterious forms of life. Isolated bacteria, floating around in the seawater, are referred to as planktonic, but when they alight on the surface of a grain of sand and team up, something amazing happens: the whole becomes greater than – and very different from – the sum of the parts.

Now I, for one, did not know much about biofilms until I came across these amazing images a while ago. But I should have done, since I carry them around continuously, and encounter them frequently. My quest for further understanding of these constant companions led me to the superbly informative website of the Center for Biofilm Engineering at Montana State University. Herewith, from their “Biofilm basics” section:

You may not be familiar with the term "biofilm," but you have certainly encountered biofilm on a regular basis. The plaque that forms on your teeth and causes tooth decay is one type of bacterial biofilm. The "gunk" that clogs your drains is also biofilm. If you have ever walked in a stream or river, you may have slipped on biofilm-coated rocks.

Biofilm forms when bacteria adhere to surfaces in moist environments by excreting a slimy, glue-like substance. Sites for biofilm formation include all kinds of surfaces: natural materials above and below ground, metals, plastics, medical implant materials—even plant and body tissue. Wherever you find a combination of moisture, nutrients and a surface, you are likely to find biofilm.

A biofilm community can be formed by a single bacterial species, but in nature biofilms almost always consist of rich mixtures of many species of bacteria, as well as fungi, algae, yeasts, protozoa, other microorganisms, debris and corrosion products. Over 500 bacterial species have been identified in typical dental plaque biofilms. Biofilms are held together by sugary molecular strands, collectively termed "extracellular polymeric substances" or "EPS." The cells produce EPS and are held together by these strands, allowing them to develop complex three-dimensional, resilient, attached communities. Biofilms can be as thin as a few cell layers or many inches thick, depending on environmental conditions.

And here’s their illustration of the biofilm life cycle (perhaps “bio-horror film” might be a more appropriate name – this is going on in my mouth?):

Biofilms are, quite literally, everywhere, and they present huge puzzles and mysteries. But understanding exactly what they are and how they work is vital. Efforts to combat bacteria focus on their planktonic manifestations, but biofilms are different, and are more resistant to attack than their free-floating versions. And what is more, the traditional approach to developing antibacterial weapons and strategies is to culture the critters in the lab and experiment on them. Pluck a bunch of bacteria from the environment and 99% of them will prove to be “unculturable” – they simply won’t grow in the lab. So what makes them grow in nature? This is where the work of D’Onofrio and his colleagues comes in – they are identifying the growth factors produced by culturable bacteria that trigger growth in their previously unculturable relatives. It would seem to be an extremely complex relationship in which some members of a biofilm community are intrinsically critical for the growth of others – it’s one big co-operative.

This has to be related to another extraordinary characteristic of biofilms: their DNA expression – which genes are switched on and producing proteins – is different from that of the same group of bacteria when they are separate; a biofilm is a different kind of organism in its own right. It’s no wonder that the Center for Biofilm Engineering describes how

The study of biofilms has skyrocketed in recent years due to increased awareness of the pervasiveness and impact of biofilms on natural and industrial systems, as well as human health. Biofilms cost the U.S. literally billions of dollars every year in energy losses, equipment damage, product contamination and medical infections. But biofilms also offer huge potential for bioremediating hazardous waste sites, biofiltering municipal and industrial water and wastewater, and forming biobarriers to protect soil and groundwater from contamination. The complexity of biofilm activity and behavior requires research contributions from many disciplines such as biochemistry, engineering, mathematics and microbiology. New insights into the mysteries of biofilm are being published daily in a wide variety of science and engineering journals.

But there are always two sides to every coin, and the story of bacteria and sand is no exception. The prediliction of planktonic bacteria for alighting on a grain of sand and massing themselves into a biofilm is the basis for slow sand filters. Originally developed in the UK in the nineteenth century, and influential in the eradication of cholera, these water filtration systems continue to be used for metropolitan water supplies and, in modern refinements, on a small scale in developing countries. The basic principle is simple: a biofilm forms on the surface of a bed of sand and continues to attract micro-organisms from the passing water. The biofilm or Schmutzdecke (another wonderful word) builds up significantly, removing up to 99% of the bacteria from the water – but, of course, eventually the sand must be cleaned. This technology is now very sophisticated, and so, although we have yet to understand how it all works, we should be grateful for the attraction of the surface of a grain of sand to passing bacteria.

[The extraordinary scanning electron microscope images are reproduced here under a Creative Commons Attribution 2.5 License, courtesy of the Lewis Lab at Northeastern University. Images created by Anthony D'Onofrio, William H. Fowle, Eric J. Stewart and Kim Lewis.]