Blog Post Image: Under California: An ancient tectonic plate

Mostly gone, not forgotten. The Isabella anomaly (IA, above), is at the same depth (ca. 100 km) as other fragments of the Farallon plate under Oregon and Washington, is on a line with fragments off the California coast, and has a similar seismic tomography signature. Image credit: Forsyth lab/Brown University (Click image to enlarge)