The new seismic hazard maps are out! The PI says:
The U.S. Geological Survey’s new seismic hazard maps, released this week, show two more earthquake faults in Western Washington: one near the Canadian border, the other east of Port Angeles.
Lucky us. We already have plenty of faults around here that could give us a “big one.” Of course, the “Really Big One” is likely to be a Cascadia Subduction Zone quake. From the Pacific Northwest Seismic Network:
HOW BIG ARE CASCADIA SUBDUCTION ZONE QUAKES?
Great Subduction Zone earthquakes are the largest earthquakes in the world, and can exceed magnitude 9.0. Earthquake size is porportional to fault area, and the Cascadia Subduction Zone is a very long sloping fault that stretches from mid-Vancouver Island to Northern California. It separates the Juan de Fuca and North America plates. Because of the very large fault area, the Cascadia Subduction Zone could produce a very large earthqauke, magnitude 9.0 or greater, if rupture occurred over its whole area.
On the other hand, the PI also reports:
Scientists now estimate that potential ground motion in the western United States is 30 percent lower than they previously thought for the kind of quakes caused by long-period seismic waves that would affect taller, multistory buildings.
Now, a digression…
A commenter on the Seattlest post links to The Street-Smart Naturalist: Field Notes from Seattle (a preview is available on Google Book Search), which looks great. I wonder how I’ve managed to miss it. The commenter mentions the chapter on The Fault, of course, but the first chapter caught my eye, too: “The Eagles” (about the birds, not the band). See, Seattle has Eagles. Bald Eagles. Shortly before we moved into our house, we were sitting on the front steps waiting for the inspector to arrive. We looked up and saw a Bald Eagle soaring overhead. We were both amazed. I knew the population had rebounded since the DDT days, but still. I’ve seen Bald Eagles in and around Seattle many times since and I’m still a little awe-struck every time.