TCS Daily

The Last Wave

By Russell Seitz - January 13, 2005 12:00 AM

Every winter, surfers gather on the North Shore of Oahu to try to ride Pacific combers even taller than the walls of water that swept the Indian Ocean on Dec. 26.

Nobody surfs a tsunami, but some of the worst hit shores owed their tourism almost exclusively to their extraordinary waves.

The tsunami has done more than decimate hard core surfers, whether caught ashore, or facing their last wave on the Andaman Sea. From Unahatuna on Sri Lanka, to Indonesia's Nias Pipe, it transformed the seabed itself.

Like an iceberg's, most of the seismic sea wave's mass and momentum lay far below the water line.

Inhuman Power

An arc of darkness 1,000 miles long -- the Sunda Trench -- lies beneath the Halcyon surface of the Andaman Sea. The water pressure in its 4,000-fathom depths is higher than the inside of a rifle breech. If some wannabe Captain Nemo were to fire at the first set of big teeth to come along down there, the ensuing scene would be straight from a Road Runner cartoon -- the bullet would halt halfway out of the barrel, and snap back from whence it came. Even a hand grenade might pop like a flash bulb without exploding.

Real world physics puts the same damper on all explosions -- conventional, nuclear or volcanic. A Hiroshima-sized bomb would dazzle the abyss with light, but forget about a mushroom cloud. Its energy would be dissipated in blowing a preposterously small steam bubble barely the size of a hot air balloon.

No rocket science is required to realize that the seismic forces that defied those pressures must have been phenomenal. Imagine 10 thousand Hiroshima bombs strung out 100 yards apart, exploding in sequence at a rate of 10 a second. Their total would be the 200 megatons of explosive power that snapped a contorted strip of seabed forward on Dec. 26, slapping the basalt seafloor and the kilometers of water atop it upward 10 meters.

But that was just one edge of a three dimensional cataclysm in which over a thousand times more energy was released. The bulk went into shoving the Indian plate down under the Pacific Rim and in translating the Burma plate up and over it. -- an event so inhuman in scale that the worlds nuclear arsenals fail utterly as units of measure it was not thousands of millions of kilotons, but millions of millions. Not even Carl Sagan could count that high.

The massive event launched a column of seawater four-miles thick along a stretch of latitude 15 degrees long - 900 nautical miles. For an instant, an unstable ridge stood out like a dragon's back above the Andaman Sea before fissioning clear down to the seabed into the symmetrical waves that raced towards Sumatra and Thailand, and beyond

With 200 megatons of impetus driving a trillion tons of mass, it's a mercy that the death toll merely dwarfs Hiroshima, and that after only two weeks , the daily addition to the butcher's bill has shrunk to the equivalent of 9-11's casualties . It is providential that so many of the million Sumatrans who vanished into bureaucratic limbo are returning alive.

Cruel Destruction

When death becomes a statistic, it can take a computer model to apprehend the devastation's scope -- a sobering one may be viewed at

Yet it fails to convey how far inland the carnage extended. Many died believing a 10-meter wave would spare them 11 meters above sea level. But behind the slowing face of a deep-water tsunami approaching land is a pile of water as wide as the English Channel. It comes on shore twice as fast as you can run, and in running far inland, it stays ashore deeper than the tallest man far, far longer than it takes to drown. Its forward momentum will carry a crest 10 meters deep another 10 meters or more uphill. Safety may begin only in the treetops -- if you can hang on.

And the farther the water propagates over the land, the farther out to sea its retreat can drag victims. Take it from a body surfer -- even five-meter waves in clear water challenge the survival skills of a strong swimmer. The scene of water churning opaque, awash with ragged edged tin and rafters, is a surfer's worst nightmare. It is a nightmare that overtook thousands of them, body and board; Asian, African, American and European. The tsunami region has been a Mecca for the sport. And surfers were killed in disproportionate numbers because they gravitate to and often stay on the beach.

So this summer will not bring endless lines of boards awaiting the arrival of the set of waves along usually crowded breaks from Malibu to Nantucket, Devon to Hawaii.

And when summer ends, those who return to where the rogue wave decimated their friends will find that in tearing people from the land, the tsunami also wreaked havoc on the living coral in the sea. Only unlike reef biologists, they will not see unmitigated catastrophe, for coral can be a surfer's worst enemy. It kills far more of them than tsunamis do.

The Gift

Idyllic as Caribbean waters may seem, many of its windward shores defy surfing. Board and body surfers alike need room to ride, and a user-friendly bottom for when they fall, or waves break over them. Surfers get to know sea bottoms as intimately as clothes do the inside of a washing machine. They prefer sand or shingle shoals, not the biological equivalent of barbed wire, with sea urchins doing the office of land mines.

Surfers sailing the length of the Windwards and Leewards encounter only a few places, such as Antigua's Half Moon cove, Barbados' Crane Beach and Bequia's Hope Bay that pose little risk of laceration . Some of the softer shores are the result of hurricane damage, and a tsunami is the one force on Earth able to do as much or more.

At many places along this great wave's path, coral heads, the growth of which over centuries and millennia had shaped to resist the incoming surge, were struck instead by an uphill avalanche as successive tsunami swells receded from the land. As elephantine boulders of brain coral bowled through forests of pinnacles, and rolled back and forth, their abrasive scree clattered across once pristine barrier reefs, burying what it failed to break.

Thousands of underwater acres that were once a day-glow marine Disneyland have become a skeletal moonscape that will take generations for life to re-colonize and regenerate. But long before scuba divers or snorkelers can see anything below the waterline but cause for weeping, surfers will flock to exult in the destruction.

Scores of offshore breaks once potentially lethal to those who wipe out onto hard coral have become a new and unexplored surfer's paradise. Inshore, dozens of coves once only of interest to body surfers with a strong death wish have been shorn of scimitar thickets of staghorn -- turned into sand-bottomed wave machines.

Nature never takes away without giving. To those whose livelihood depended on the reefs until the Sunday before the New Year, the terrible beauty their metamorphosis holds for the next generation of surfers may be a gift from the cruel sea.

Russell Seitz is recuperating from injuries inflicted by a rogue wave at the Madekasham break on Nantucket.


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