Atwater is a scientist with the U.S. Geological Survey whose expertise is studying ancient earthquakes and tsunamis.

He digs in the soil for evidence of natural disasters that occurred in the past – to provide clues to the risks we face today.

Atwater says the massive earthquake and tsunami that struck northeastern Japan last week had a precedent. It occurred in the 9th century. Based on written records from that time and sand deposits left in the ground, Japanese scientists conclude that on July 13, 869, a tsunami swept more than 4 kilometers inland in the area around the modern-day city of Sendai.

Using similar detective work, Atwater concludes that a massive tsunami struck America’s Pacific Northwest more than 300 years ago. He and his colleagues found evidence of this tsunami in sediments along the coast of California, Oregon, Washington, and British Columbia. They believe this is the same tsunami that was recorded striking Japan in January 1700, and that it originated on this side of the Pacific.

Atwater and his colleagues recount their detective work in The Orphan Tsunami of 1700—Japanese Clues to a Parent Earthquake in North America.

Join the conversation:

* Which coasts are threatened by tsunamis?
* What can old documents and sediments tell us about today’s tsunami hazards?