Caption: San Andreas Fault, a transform boundary between the tectonic plates the North American Plate and the Pacific Plate which are both major plates. North of the San Andreas Fault is the convergent boundary (AKA subduction zone) between the North American Plate and the microplate the Juan de Fuca Plate.

The San Andreas Fault is one of the relatively few places where a tectonic plate boundary crosses land. The much of the coast of Southern California and Baja California is sliding northwest and will become an island in maybe of order 20 Myr (see Wikipedia: San Andreas Fault: Plate boundaries).

For more information on the San Andreas Fault, see USGS The San Andreas Fault site

Credit/Permission: U.S. Geological Survey (USGS), before or circa 2005 / Public domain.
Download site: U.S. Geological Survey (USGS).
Image link: Itself.
File: Earth: geology: plate tectonics file: usgs_007_san_andreas.html.