Author Brian Atwater et al; book report by Brian Giles

A mysterious tsunami in January of 1700 occurs on the coasts and harbors of Japan. Mysterious because there was no causative earthquake that anyone noticed. It was so odd that many of the locals responsible for record keeping put in writing the complete strangeness of this occurrence. One called it an orphan tsunami, others called it a series of “extreme high tides”.

At the same time, no one who experienced the parent of this tsunami, a Cascadia subduction zone earthquake, had developed writing in what was to become Washington, Oregon, or British Columbia. Captain James Cook’s future visit was still the better part of a century into the future. Native oral tradition mentioned a flood, canoes stranded in the tree tops, Cape Flattery becoming an island.

Then, the first of many detectives began working the case. Geologist Brian Atwater, PhD, noticed in the Copalis river banks what was called a “ghost forest” of dead Western Red Cedar stumps with associated buried Sitka spruce.  At low tide, the layers of mud and sand observed from a kayak could be read like a book. By the right person. 

Atwater and others narrowed down the date for the demise of the ghost forest through Carbon 14 dating, but 1695-1720 was not as precise as the date known to the Japanese. In consultation with David K. Yamaguchi, PhD, a Japanese-American dendrochronologist, the year of forest death was determined to be 1699-1700.

Now the Japanese geophysics detectives and historians got together with the American team. Atwater and Yamaguchi were welcomed to Japan and the final day of the subduction zone slip became known: January 26, 1700. A 10-hour transit of the generated waves put the damage in Japan into January 27, and multiple waves were documented by mayors, fishermen and others who noted the strange nature of what they hesitated to call a true tsunami. Rice in transit was lost. Sailors were killed. Houses, boats and warehouses were destroyed.

This compelling book compares notable earthquakes experienced in historical times with the 1700 event. Chile, 1960. Alaska, 1964. Kamchatka, 1952. Of course, the Sumatra tsunami of 2004.

All this detective work is responsible for augmented building codes and an expanded universal tsunami warning sign network. Scientists agree that we are probably overdue for another subduction zone slip.

Documented multi-tsunami evidence has been found in the Swantown area behind West Beach on Whidbey Island. You may want to do some detective work of your own. Start with this book?