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by Larry

June, 2005

Tsunami Update

In our 1/21/05 newsletter, I addressed The World's Worst Natural Disasters. At the time, the death toll from the 12/26/04 earthquake and tsunamis was estimated at 160,000. The figure has since been dramatically adjusted. There are now roughly 300,000 individuals known to have died in that tragedy or who are still missing and presumed dead. Both in terms of the human cost and the devastation to communities and economies, that day's calamities probably rank it as the single most damaging tsunami event in history, though greater losses, as a percentage of those living then, certainly occurred from giant prehistoric tsunamis.

Scientists say that the energy release of the 12/26/04 tsunamis was equivalent to the power of 23,000 Hiroshima atomic blasts. A cubic meter of water weighs about one ton. So, swiftly moving, an ocean wave exerts a great deal of force. In places, the tsunamis rose over 31 meters (higher than 10-story buildings). Some of the waves swept several kilometers inland. There was not just one huge tsunami at each affected area, but a succession of mammoth waves that came and went, often at great speed, churning people, animals, private vehicles, soil, parts of buildings, trains, trees, fishing boats, rocks, other vegetation, sand, and even ships, whatever was not securely anchored, together in a natural blender. Many tens of thousands of victims will probably never be found. There is no good film footage of the tallest waves. Those who stayed to make such video recordings were likely destroyed along with their cameras. But the wave heights can be determined from how far up the beach bluffs and hillsides have been completely stripped, scoured by the passing floods, or by the level of the debris left by retreating waters.

The earthquake that catalyzed the huge tsunamis that day was by itself more powerful than the combined worldwide earthquakes of the previous five years.

Changes in the earth's crust occasioned both by the quake and the ensuing tsunamis are thought to have rendered it less stable, making further great tremblers there more likely. In addition, the globe is now slightly smaller in diameter, resulting in the planet turning a little faster than before, just as an ice skater increases her or his rate of spin by bringing the arms in closer to the rest of the body. If it seems you don't have enough time in a day, that could now be a valid insight. Each rotation of the earth on its axis is a little bit shorter than before 12/26/04.

Experts say there is as much threat of tsunami-creating earthquakes in the Indian Ocean region as prior to December, 2004. They are accordingly urging prompt implementation of a tsunami warning system in that part of the world.


Researchers Warn of Tsunami Threat. Christopher Joyce on Morning Edition - NPR; March 17, 2005.

Study Tracks Path of Indian Ocean Tsunami. Christopher Joyce on All Things Considered - NPR; June 11, 2005.

Tsunami: The Wave That Shook the World. Nova - PBS; March, 2005.

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