Still Standing: Tsunamis Won't Wash Away Maldives Atolls
Gramling, C., Science News
Tiny coral-reef islands such as those in the Maldives archipelago may appear fragile, but they aren't easily swept away, a new study shows. The waves of the Dec. 26, 2004 tsunami were devastating to the islands' inhabitants, but researchers now find that the waves' geological impact on the islands themselves was minor and had little effect on their long-term stability.
The Maldives includes about 1,200 coral-reef islands, or atolls, in the Indian Ocean. The reefs sit atop the craters of a string of undersea volcanoes south-southwest of India. The low-lying islands are vulnerable to sea level rise. Monsoon winds, which reverse direction from winter to summer, also impose a seasonal effect on the shorelines, redistributing beach sands to alternating coasts.
Many scientists had assumed that the islands would be highly vulnerable to tsunamis, says coastal geomorphologist Paul Kench of the University of Auckland in New Zealand. In the absence of previous data on the impact of tsunamis on the structure of reef islands, Kench and his colleagues set out to assess how the 2004 disaster affected the long-term stability of the Maldives.
The tsunami, generated by an earthquake 2,500 kilometers away off the coast of Sumatra, reached the eastern islands of the Maldives within 4 hours. A series of surges inundated the country, leaving 80 people dead and many islands uninhabitable. …