Another Life: On a day when the tsunami death-toll was rising by thousands every hour, it seemed almost unfeeling to go beachcombing with scientific minutiae in mind. But reports of odd things washed up in Sligo could not be resisted, on the chance that Thallabawn might also have a share of them, writes Michael Viney.
In the teeth of a strong westerly I leaned my way slowly to the tideline, wiping away wind-tears that might blur any glimpse of "floating transparent gooseberries" in the apron of foam beyond.
That I found none will not stop me writing about them, because Phronima sedentaria, besides being hitherto almost unknown among this island's flotsam, is a deep-sea creature combining ecological ingenuity with memorable appearance. Sligo naturalist Dr Don Cotton, viewing under the microscope one of the 100 or so he had collected, found himself eye to eye with "something from outer space". Phronima was, indeed, the model for the monster in the 1979 classic sci-fi horror film Alien. My drawing is based on one photographed by another Sligo beachcomber, John-Mark Dick of Skreen.
A shrimp-like amphipod about 3cm long, Phronima has, in close-up, two giant eyes on a hammer-shaped head and an array of weapons "giving it the appearance", as the BBC's Blue Planet put it, "of a transparent Swiss Army penknife".
Boarding a passing (and even more perfectly transparent) sea squirt among the deep-water plankton, it carves out and eats its gelatinous middle, taking up residence inside the glass barrel so created and rearing its offspring there. It has been reported pushing several barrels like a string of beads, each full of young.
This parasitic lifestyle is pursued at depths from 80 down to 400 metres, where the Phronima's huge compound eyes collect what light there is.
America's William Beebe, studying deep-sea life through the porthole of his bathysphere in the 1920s, thought it an animal "especially blessed with eyesight". It was a westerly wind that brought the first reported specimens of Phronima to be washed ashore in Ireland - just three of them, still in their barrels, found by marine biologist Dan Minchin on Inch Strand in Kerry in the autumn of 1985. The hundreds recorded after Christmas on strands on the Sligo coast and the Mullet Peninsula in Mayo may have been carried in the deep current that flows north from the mouth of the Mediterranean and then churned up to the surface. Whatever their origin, these tiny animals take one's thoughts out and down to an ocean world still at the far edge of human awareness.
The Indian Ocean tsunami sent me back to a book I discussed here some three years ago, with perhaps undue light-heartedness. Tsunami: The Underrated Hazard (Cambridge University Press, 2001) is by Prof Edward Bryant of the University of Wollongong, Australia - a man whose views, I feel sure, are now in great demand.
He points to evidence of past "mega-tsunami" along coastlines, including those of western Europe, caused not by earthquakes but by huge submarine landslides or meteor impacts. According to Bryant, there were at least seven major submarine slides off the west coast of Ireland between 30,000 and 8,000 years ago.
At the edge of the continental shelf west of Ireland (which approaches to a mere 30km off north Mayo and 60km off south-west Kerry) there are precipitous slopes thickly rimmed with glacial sediment since the end of the last ice age. Huge slumps or slides of rock and mud lie piled at the bottom of the walls of the Rockall Trough. In a dramatic epilogue to Bryant's book, a small Sunday earthquake that nobody notices - a mere three or four on the Richter scale triggers a new slide big enough to generate a tsunami. It takes two hours to reach the west coast of Donegal.
"Headlands along 350 kilometres of rugged coastline were swamped," his scenario runs, "while flat-pocket beaches in sheltered embayments were totally eroded. The wave was amplified by funnelling in embayments such as Loughros More and Gweebarra bays, and into Lough Swilly running down to Letterkenny. Here the wave reared from eight metres along the open coast to over 15 metres inside embayments." Further east, the death toll mounts: "University students living in the coastal communities of Portstewart and Portrush succumbed to the waves . . ."
Since Bryant researched his book there has been intensive mapping of the Rockall slopes and cliffs, along with those of the great Porcupine Seabight amphitheatre off the south-west of Ireland.
Foremost in geologists' minds has been the possible impact of landslides on deep-sea oil and gas installations - landslides triggered, conceivably, by the shocks of seismic exploration.
Tsunamis, mega or mini, may now need to enter their computations of risk and warning.