Geologists find tsunami hazard in eastern Aleutian Islands

A 125-mile section of the eastern Aleutian Islands that was once considered unlikely to generate earthquakes may be a future source of temblors — as well as potentially devastating tsunamis that could hit Hawaii.

Field work by U.S. Geological Survey scientists on an island near Dutch Harbor revealed "sand sheets," or deposits of sand lifted off beaches and moved a half-mile inland.

Geologist Robb Witt says that shows large tsunamis have hit Sedanka Island frequently in geologic terms — about every 300 to 340 years.

Scientists had thought that the section of the Aleutians was over a "creeping" fault where tectonic plates move continuously without building up strain that leads to earthquakes.

Witt says Hawaii officials have used information from the USGS study to broaden tsunami evacuation zones.