Tsunami facts

Tsunami facts

There’s been a lot of talk on Blogs about why no early warnings were issued to countries and populations in the path of Sunday’s tsunami. Hmmm… It’s so easy to be wise after an event.

The Hindustan Times explores this idea:

“Thousands of lives could possibly have been saved if India and Sri Lanka had been part of a 26-nation group that operates an international tsunami warning system, say scientists of the US Geological Survey.

The US has its own warning centres in Hawaii and Alaska, but these are geared to monitoring occurrences of large seismic waves in the Pacific Ocean — and not in the Indian Ocean, where Sunday’s catastrophic tsunamis originated.

The international warning system can alert nations of potentially destructive waves some three to 14 hours before they hit the coast — sufficient time to make people flee inland. But without wave sensors in the Indian Ocean region, there was no way to determine the path of tsunamis.

Staffers at the US centres were aware of the grim possibility of tsunamis on Sunday following the massive earthquake, but they did not have a warning mechanism in this case.”

But until Sunday, the statistical probability of a tsunami disaster seemed small — as the Hindustan Times article goes on to point out:

” Tsunamis have been so rare in the Indian Ocean that people in countries of the region have never been taught to flee inland at the time of a big earthquake.

‘The last tsunami that affected the Indian Ocean was in 1883…The hazard was underestimated by a factor of 10,’ says Costas Synolakis, professor of civil engineering at the University of Southern California, explaining why experts had not pushed hard for a warning system for the Indian Ocean.

Synolakis told the Washington Post that just two weeks ago he had opened discussions with officials at the Pacific Tsunami Warning Centre in Hawaii about expanding the warning system to the Indian Ocean.

The international warning system was put in place in 1965, a year after massive tsunamis struck Alaska.”

OneWorld.net has a fascinating story about how a former wave-height monitor from Pondicherry in India now living in Singapore saw what was happening, realised its significance and telephoned home to warn them. His village was evacuated and everyone saved. But it’s difficult to see how the necessary evacuations could have been achieved in time across the region. This was a 40-foot wall of water that covered 750 miles in 100 minutes — that’s about 450mph. Just think about that — try to imagine that mass of water moving at that speed — and you get some idea of the devastating energy that pounded South Asian coastlines.