The Great Cascadia Earthquake, Jan. 26

Tuesday, January 26th marks the 316th anniversary of the last great Cascadia earthquake in the Pacific Ocean. The date was January 26, 1700, and quake was described as more than a 9.0-magnitude quake. The quake, the aftershocks and the tsunami wave that followed caused a great deal of destruction in the Pacific Northwest. From Wikipedia – Evidence supporting the occurrence of the 1700 earthquake has been gathered into the 2005 book The Orphan Tsunami of 1700, by Brian Atwater, Kenji Satake, David Yamaguchi, and others. The evidence suggests that it took place at about 21:00 on January 26, 1700 (NS).[5] Although there were no written records in the region at the time, the earthquake’s precise time is nevertheless known from Japanese records of a tsunami that has not been tied to any other Pacific Rim earthquake. The Japanese records exist primarily in the prefecture of Iwate, in communities such as Tsugaruishi, Kuwagasaki and Ōtsuchi. The geological record reveals that “great earthquakes” (those with moment magnitude 8 or higher) occur in the Cascadia subduction zone about every 500 years on average, often accompanied by tsunamis. There is evidence of at least 13 events at intervals from about 300 to 900 years with an average of 570–590 years.[16] Previous earthquakes are estimated to have occurred in 1310 AD, 810 AD, 400 AD, 170 BC and 600 BC.