Tuesday, December 28, 2004

In over our heads?

Tom's post on the Asian tsunami has me involuntarily glancing out the window at the sea. Here on the island of Exuma in the Bahamas, we are only a few dozen feet from the shore and about 10 feet above sea level -- highly vulnerable to a wave such as the one that devastated communities along the Indian Ocean.

Fortunately, if history is a guide, we don't have much to worry about. In the 500 years since European colonization, there have only been about a half-dozen recorded tsunamis in the Caribbean region, with a total of about 50 deaths. Most were caused by local earthquakes, but one resulted from the Great Lisbon Earthquake of 1755.

The latter quake occurred on an active fault in the Atlantic off Portugal and is sure to be repeated, although no one knows when. As for the predicted Canary Island landslide, triggered by a volcanic eruption, well, there's quite a bit of controversy about that. A possible meteorite impact in the Atlantic, although utterly certain to happen someday, won't keep me awake at night.

But storm surges due to hurricanes, now that's another story. Hurricane Andrew in 1992 caused surges in these islands of over 4 meters. The old folks here still talk about the 1926 hurricane that sent waters 5 or 6 meters deep across Exuma.