The San Andreas Fault - one of the most-famous faults on Earth - is located in California. Long associated with the state's "down side" - California's many earthquakes - the San Andreas has another story.
According to Dr. Iain Stewart - who pays a personal visit to the fault in this video clip - much of California, and its history, has been directly impacted by the San Andreas. Some of that impact has been surprisingly positive.
California's cash-flow, for example, is enhanced by around $100 million - every year - because of the fault's positive influence on California's geology.
After watching this clip - from the BBC's "How Earth Made Us: Deep Earth" - you may never think about the San Andreas Fault in quite the same way.
Clip from the BBC's "How Earth Made Us: Deep Earth," with Dr. Iain Stewart. Copyright, BBC, all rights reserved. Clip online via BBC's Channel at YouTube and provided here as fair use for educational purposes and to acquaint new viewers with the series.
To purchase the episode, or the entire series, visit BBC's episode guide for "How Earth Made Us."