Bedtime Reading

by Thomas Beutel

I tend to read non-fiction more than fiction, especially late in the evening, and one of my favorite reading topics is seismology. There are many good books about it on my bookshelf and one of my favorites is Cascadia’s Fault by Jerry Thompson. It chronicles the research conducted in the 1980s that uncovered the true nature of the Cascadia subduction zone.┬áPrior to that time the subduction zone had not been considered a threat for large earthquakes. A lot of interesting fieldwork was done to show just the opposite.

My favorite story is on the fieldwork done by Brian Atwater and his colleagues to show that a grove of of dead cedars had all drowned in an earthquake in the year 1700. I think the reason I find this story so compelling is that it was not at all intuitive that the dead trees would be at all related to an earthquake. The trees were easy to overlook and although some locals had known about them, it was Atwater who made the connection. And when he did find them, it still took much work to uncover their actual date of death. The outer layers of bark had rotted away, and it was a while before a solution was found using tree-ring analysis of the roots. The date was later corroborated with an orphan tsumani record from Japan.

I have probably read this account four or five times and I’m still in awe of all the connections that had to be made to make this story complete. So many opportunities to miss clues and yet it all came together to tell a compelling story of a massive earthquake over 300 years ago.