Sunday, September 14, 2008

It's all San Andreas' Fault

On a visit to the Point Reyes National Seashore, we began by walking the Earthquake Trail. The displacement between the sections of fence in the photo above (lower to the left, upper to the right) shows the extent to which the land was shifted by the great 1906 earthquake that devastated San Francisco.

The three posts marking a line going toward the fence in the background show the approximate alignment of the San Andreas Fault. The Fault roughly marks the boundary between the North American and Pacific tectonic plates. So, I can say that, when I took this photo, I was standing on the Pacific Plate, to the west of the Fault, looking at the North American Plate, to the east (and right) of the line extending through the posts.

Fortunately for me, the earth did not move during my visit to this very excitable spot. I'm told that Northern California experienced a small earthquake a few days after we left.