The orphan tsunami of 1700—Japanese clues to a parent earthquake in North America

TLDR

Japanese witnesses in 1700 recorded minor flooding and damage from a tsunami whose parent earthquake was unknown, and it was not linked to its source until the 1990s through discoveries in North America and Japan, a connection echoed by the 2011 tsunami. The book reconstructs the 1700 orphan tsunami using North American and Japanese evidence, and its findings inform current Cascadia earthquake and tsunami precautions. First posted September 15, 2005; revised December 1, 2015; contact Brian Atwater, U.S.

Abstract

First posted September 15, 2005 Revised December 1, 2015 For additional information, contact: Brian Atwater U.S. Geological Survey at Department of Earth and Space Sciences University of Washington 351310 Seattle WA 98195-1310 206-553-2927 [e-mail] A puzzling tsunami entered Japanese history in January 1700. Samurai, merchants, and villagers wrote of minor flooding and damage. Some noted that no parent earthquake had been felt; they were wondering what had set off the waves. They had no way knowing that the tsunami had been spawned during an earthquake along the coast of northwestern North America. This orphan tsunami would not be linked to its parent earthquake until the middle 1990s, through an extraordinary series of discoveries in both North America and Japan. The Orphan Tsunami of 1700, now in its second edition, tells this scientific detective story through its North American and Japanese clues. The discoveries underpin many of today’s precautions against earthquakes and tsunamis in the Cascadia region of northwestern North America. The Japanese tsunami of March 2011 called attention to those hazards as a mirror image of the transpacific waves of January 1700.