The term 'San Andreas, for one' is referring to the San Andreas FAULT, a major FAULT line in California. The crossword solutions for this term are 'FAULT' (5 letters) and 'faultline' (9 letters). The San Andreas FAULT is a transform FAULT that runs roughly 800 miles through California and is the boundary between the Pacific Plate and the North American Plate. It is responsible for some of the most powerful earthquakes in California's history.