Through The Sandglass

Military forensics: a reader's query

 
I have frequently noted my pleasure in regularly receiving “out of the blue” comments and e-mails – I find myself in contact with all kinds of people from around the world with whom I would never have otherwise intersected, on an amazing range of topics, many of which are completely new to me. All of this because of a mutual interest in all things arenaceous.

Here’s a case in point – together with a question for anyone who might be able to shed light on this. The unique nature of any particular family of sand grains from a specific location, be it a river sand bank or a coastal beach, has long provided forensic science with a tool for location identification. This has not only been applied to any number of cases of criminal forensics, but also, for example, to archaeological and military investigations. I described the classic military example in Sand:

In late 1944, balloons 9 meters (30 ft) in diameter appeared in the skies above the United States. Landing from the West Coast to Michigan, they carried a deadly cargo: incendiary bombs. Although the only casualties over the following months were, tragically, members of a Sunday school group attempting to retrieve one that had landed, the potential danger to life, towns, and forests was considerable. It was apparent that the weapons had blown in from the Pacific, but where had they been launched? The devices had an automatic altitude-regulation system, releasing hydrogen or ballast to maintain height. The ballast bags were filled with sand. The U.S. Geological Survey’s Military Geology Unit, established in 1942, was tasked with identifying the sand. The family of grains was consistent from one retrieved ballast sample to the next, and unique. Distinctive forams and other microscopic shells, together with small amounts of unusual mineral grains in among the granite debris, correlated precisely with beach sands described in prewar geological reports from two locations on the east coast of Japan. Air photographs identified hydrogen production plants at these locations, which were then targeted and destroyed.

Recently, a reader of this blog, a self-confessed “WWII history buff” sent me a series of photographs and asked for my views on whether there was any chance of figuring out the provenance of the sand grains shown at the head of this post. And where did these grains find themselves used as a military application? As camouflage on a German helmet:

The military unit would seem to be a naval artillery group, and France would be the likely origin. But does anyone have any ideas as to a more specific location?

Crater delta, tephra sand

 
Flush sediment into a body of water and a delta will form – regardless of scale or environment, it’s just one of those ubiquitous natural processes.

Taking advantage of a recent visit to the city of Bandung in central West Java, my companion, familiar with the region, suggested the scenic route back to Jakarta – and some scenery it proved to be. Being prominently positioned on one branch of the Pacific “ring of fire,” Java owes its topography to its volcanoes, and it’s these towering and long-lived eruptive centres that form the backbone of the island and the backdrop to Bandung. One of them, Tangkuban Perahu (or Parahu in the Sundanese dialect) reaches an altitude of nearly 2100 meters and is something of a tourist destination, since an easy drive brings you to the rim of the crater and a spectacular landscape. Climbing above the tea plantations, it’s not long before you recognise that you’re in a volcanic neighbourhood: the entire atmosphere becomes sulphurous, the whiffs of hydrogen sulphide developing into an all-pervasive stink. And then, there you are on the lip of a crater in what is described technically as a dormant volcano. “Dormant” is fine when you’re there, but tomorrow? Tangkuban Perhau last erupted in 1983 and in 2005 an alert lasted for some time as rumbling seismic activity suggested the threat of an impending eruption. The palm-roofed “shelters” along the road, were, I presumed, in case of rain not volcanic pyrotechnics.

The crater is but the current focus of a long period of eruptive history and is but a minor feature of a much larger caldera, the roughly circular chasm formed when the entire edifice blew itself up around 190,000 years ago. For a minor feature, however, it’s still awe-inspiring and huge. Steam vents from a distant fumarole, but its roaring sound can be distinctly heard from the rim. In the floor of the crater is a toxic-looking lake – and a complex of deltas, water from rain and the fumaroles, sediment from the crumbling crater walls (recent landslides are disturbingly visible around the cliffs) and the ongoing minor eruptions. Well, mainly minor: close inspection reveals that the surface of the delta is littered with what must be boulder-sized debris – grain sizes that would seem to be inconsistent with those of the rest of the delta sediments….

  
The majority of the recent eruptions have been phreatic – explosive events resulting from molten magma encountering near-surface groundwater and causing instantaneous detonation of vast volumes of steam and debris, hurled into the air and cascaded back to the surface. These deposits, tephra, have no respect for grain size organisation – they contain everything from clay to boulders:

 
And, of course, tephra deposits contain large amounts of newborn sand. Small streams transport this down the mountain, and provide the opportunity for a sampling of this geological nursery. Angular grains of volcanic glass, individual crystals, rock fragments, and the occasional perfect globule:

The name Tangkuban Perahu refers to an upturned boat – the volcano of course comes with a legend, one of eternal youth, unrequited Oedipal problems, demons, a dam, and a faked sunset. But the reality of the landscape outdoes any legend.

 

[A good geological report on the eruptive history and construction of Tangkuban Perahu can be found here – note the designation of “sandy ash” layers.]       

Ozymandias

The United Arab Emirates seem to have a monopoly on follies on a grandiose and megalomaniacal scale when it comes to sand. Not, of course, that they use the vast sands of the desert hinterland that herd their cities on to the shores of the Persian Gulf – those sands are useless for their gigantic construction projects; rather, they dredge biblical volumes of essentially irreplaceable marine sands from the Gulf. These they convert into concrete to build, for example, the Burj Al Arab, the world’s only seven star hotel (self-proclaimed) and the outrageous developments of Ras Island, or pour and compact into the artificial islands that comprise the monstrous absurdities of the famous “Palm” developments and “The World” – now largely suspended as a result of the economic setbacks experienced by the rich and only somewhat famous, and reportedly, like the world’s economies, sinking. Then there are beaches cooled by water pipes in the sand, and golf courses in the desert – including the famous billion dollar Tiger Woods resort that remains mostly desert.

 
But now we have perhaps the finest example of self-aggrandizing projects. Although completed a few years ago, this has only been picked up in the world press over the last few days – here, from the UK’s Daily Mail:

Hamad, the biggest name in the desert: Arab sheikh carves two-miles-long name in sand until it's visible from SPACE

Every child has written their names on the beach at some point.

But whereas most people's 'sandwriting' is washed away, one super-rich Arab sheikh has ensured that his doodles will last a little longer. Hamad Bin Hamdan Al Nahyan, 63, has scrawled his name in sand on an island he owns with letters so big they can be seen from space. The word 'HAMAD' measures 1,000 metres high and is a staggering two miles long from the 'H' to the 'D' on the Al Futaisi island. And rather than allow the writing to be washed away by the ocean, the letters actually form waterways that absorb the encroaching tide.The ruler's name is even visible on Google's map service.  Hamad dreamed up the idea and had his workmen toil for weeks to craft the enormous piece of sand graffiti. It is not known how much it cost to make.

Anything's possible: Hamad, 63, ordered workers to write his giant name in the sand. However, the sheikh boasts a personal fortune second only to the Saudi king's. Hamad, also known as the 'Rainbow Sheikh', is a member of the Abu Dhabi Ruling Family. He is understood to have some 200 cars including seven Mercedes 500 SELs painted in different colours of the rainbow which he stores in a giant pyramid. The Arab sheikh has a taste for doing things on a large scale. He built the world's largest truck - eight times the size of the Dodge Power Wagon, with  four bedrooms inside the cabin. Hamad constructed a motor home in the shape of a giant globe which is exactly 1 millionth the size of the actual earth.

Alongside his lavish displays of wealth he has become a well-known philanthropist in medicine and supplied a complete kidney stone operating theatre to a public hospital in Morocco where he continues to fund its staff.

As the images at the head of this post illustrate (assuming that Google Earth’s historical imagery dates are roughly correct), Hamad having “his workmen toil for weeks” is something of an understatement; perhaps not surprisingly, their toil seems to have lasted a couple of years.

Beyond this, I can’t bring myself to comment further; however, for some reason or another, Shelley’s poem comes to mind:

I met a traveller from an antique land
Who said: "Two vast and trunkless legs of stone
Stand in the desert. Near them on the sand,
Half sunk, a shattered visage lies, whose frown
And wrinkled lip and sneer of cold command
Tell that its sculptor well those passions read
Which yet survive, stamped on these lifeless things,
The hand that mocked them and the heart that fed.
And on the pedestal these words appear:
`My name is Ozymandias, King of Kings:
Look on my works, ye mighty, and despair!'
Nothing beside remains. Round the decay
Of that colossal wreck, boundless and bare,
The lone and level sands stretch far away".

Sunday sand: neighbourhood differences and an important ingredient

 
Continuing the arenaceously fecund theme of my recent sojourn on the island of Bangka, once again an illustration of how coastal sands can change dramatically from one beach to another just a short distance away. I explored this earlier with an example from southern California where a submarine canyon stole all the sand travelling down the coast with the result that the beaches to its north and south were made of  different ingredients of different sizes. But Bangka faces the shallow waters of the South China Sea that separate it from Kalimantan – no canyons here, but nevertheless contrasting sands.

Bangka’s bedrock geology is dominated by granites, a couple of hundred million years old and quite distinctive – we shall return to them in a later thematic post. These granites make for some wonderful stretches of coast, the rounded boulders and rocky headlands shaping an extremely photogenic landscape.

These granites are, of course, the parent material for much of the island’s sands, weathering and rotting until their tough little quartz grains are liberated to join their companions in the rivers and along the coasts, a process that has been going on for millions of years. But once at the coast, the young quartz sands are joined by other ingredients – shell and coral fragments and a variety of other grains of different sizes that have been participants in the great game of coastal erosion for a long time. Variations in local ingredients and in the local forces of this great game – waves, tides, currents, and storms – conspire with the shape of the coast to sort and winnow sands on a grand scale: the result is that one beach will be built from distinctly different sands from the next. The sand on the left in the image at the head of this post is from one of the small beaches nestled in between the granite headlands of Parai (see the Google Earth image below), whereas the one on the right is from the broad sweep of Matras beach just a couple af kilometres along the coast. Parai’s sands are quite coarse and dominated by chunky quartz grains; those of Matras are white and extremely fine, almost powdery in feel when you pick up a handful. The beaches are different on the topographic scale, the sands different on the microscopic:

 

Left, Parai, right, Matras:

Furthermore, on the beaches of Parai, there are opportunities to observe natural scales in a different way – miniature dynamic landscapes evolving as streams of water flow down to the sea. I find these fractal landscapes compelling and endlessly watchable – as I described a couple of years ago from the Atlantic coast of France; I realise that this compulsion is somewhat weird, but I make no excuses. One of the great – and, as we shall see, important - things about the sands at Parai is that they contain scattered black grains of a heavier mineral than the ubiquitous quartz; a few such grains can be seen in the microscope photos above. As the water flows and ripples in the sand form, these heavier grains tend to get left behind on the crests of the ripples as their lighter quartz companions are hustled away. This not only makes for wonderful designs, but it makes it easy to watch the way in which the ripples are constantly shape-shifting and migrating downstream.

But so what are these heavy black minerals? The complete answer will be revealed and discussed in some detail in a later post, for they are representatives of what has, for centuries, been the driver of the island’s economy and provided its primary claim to fame. I collected a bag of sand plucked from the dark patterns on the crests of the ripples, labelled it “Bangka heavies,” brought it home, and set it out to dry. But, once dried, it seemed to me that I must have made a mistake – it looked to the naked eye no different from the usual sand, no sign of a concentration of dark grains. So I decided to repair to the laboratory (i.e., as usual, the kitchen) and attempt an amateur panning exercise. I put some of the sand in a mixing bowl, flooded it with an ample volume of water, and began gently swirling. Very satisfyingly, lo and behold, there were dark smears of the heavy grains slowly being separated from their lighter companions. I removed some of the lighter sand and repeated the exercise – and here are the results:

Just as the forty-niners of the California gold rush did, I had succeeded in a achieving a preliminary concentration of grains of interest – a process begun by nature. And here they are, some retaining much of their original crystal form, nestled – but now in much greater numbers - in among the quartz grains.

So, what is this mineral? Well, that will have to wait for another time, but meanwhile I will leave you with a couple more images of this spectacular coast.

Tracks, trails - and bubbler crabs!

 
Little did I expect, when I wrote the post about bubbler crabs a week or so ago (purely on a whim because I’d been intending to for a while), that I would shortly encounter these little sand artists up close and personal – and in profusion.

I have just returned from a restorative sojourn away from the urban chaos of Jakarta on the fascinating island of Bangka, off the east coast of Sumatra. There will be further reports (because, of course, sand figured strongly as a destination criterion), but for starters, my astonishment on walking down to the beach last Friday afternoon makes for an introduction. From a distance, I could not make out why the texture of the beach seemed so roughened – I thought that perhaps it was the result of birds marching about, but few birds were apparent. It was only on closer examination that I realised (while exclaiming loudly and enthusiastically) that the culprits were bubbler crabs – essentially the entire beach was a teeming metropolis of the critters, and smooth sand was the exception rather than the rule.

Herewith, the evidence:

 


This was an ongoing enterprise, but difficult to detect – fleeting scurryings sensed out of the corner of the eye, brief glimpses of moving sand grains as a burrow’s inhabitant disappeared down the hole. But, a little patience, a mime-like immobile stance, a finger on the camera shutter, and, lo and behold, a portrait of a bubbler crab:

On the few areas of the beach not covered in the output of the bubbler crabs, all kinds of other tracks and trails were apparent:

I have no idea what critters made this calligraphy in the sand, but this was simply that day’s version of runes that have been etched in sediments and preserved in the rocks that they would become for billions of years. The study of trace fossils, these indirect testimonies to the business of life (think dinosaur footprints) has long made a key contribution to our understanding of our ancestors. I wrote a little about this a couple of years ago – see “Giant sand worms of Torbay.”

So, but one excitement of rambling on the beaches of Bangka. And here, a sample of those beaches, and of things to come:

[For a good description and more photos of sand bubbler crabs - family Ocypodidae, Scopimera sp. - see http://wildfilms.blogspot.com/2008/05/fiddler-crabs.html and scroll down to the bubblers.]

A short travel hiatus

I am off on short trip. I will be giving a talk in Palembang, the regional capital of South Sumatra and one of the oldest cities in Indonesia. And then, taking advantage of proximity, I will take a couple of (in my view well-deserved) days off to visit the location shown above. Posting will therefore take a break, but there will be tales to tell....

[photo source can be found here - which reveals my destination intentions]

Sunday sand critter: the sand bubbler crab

I came across the existence of these delightful artists quite by accident on the Environmental Graffiti website. And, since they are denizens of this part of the world, I am looking forward to encountering sand bubbler crabs up front and personal. As Simone, who wrote the article, comments, "At low tide, the sand bubbler crabs emerge from their holes beneath the sand to gather microscopic food that the tide has brought along. They do this by collecting and sifting the sand, actually checking each grain, and rolling those parts devoid of anything useful for them into little balls (sand bubbles) that they toss behind."

Included in Simone's piece is a must-watch video - as she says, a little slow to start, but the excitement gathers pace. For more fun images and examples of the artists' work, see http://doggywisdom.blogspot.com/2010/06/sand-bubbler-crab-face-of-week-2.html, and http://geo-venture.blogspot.com/2010/08/why-does-sand-bubbler-crab-form-tiny.html. 

[Header image from Horizon2035's photostream; images above from Pawprints in the Sands of Time and George Scholz's photostream]