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The Northern San Andreas Fault

From Andrew Alden, About.com

The northern part of the San Andreas fault, some 300 kilometers long, ruptured from end to end on 18 April 1906, producing an earthquake of approximately magnitude 7.8. For several decades afterward, very little seismic activity occurred along this stretch, which reaches from Shelter Cove southeastward to San Juan Bautista. However, earthquakes have been increasing roughly since the 1980s, a period that includes the 17 October 1989 Loma Prieta event, of magnitude 7.1, in the San Francisco Bay area. While moderate and large earthquakes like 1989's are of concern and can cause deaths and damage, another great event the size of the 1906 quake is not anticipated for at least a century.

This tour of the San Andreas fault begins at the north end. The next part of the fault, beyond San Juan Bautista, is the creeping section.

San Andreas fault home page

Images 13-24 of 37

Bedrock affects the foliageFault Marked by VegetationLast exposure on the Gualala BlockThe Fault at Earthquake BeachWorth a visitTectonic Boulder Mix at Earthquake BeachLast outpost of well-traveled graniteView South from Bodega Head
A staked-out fault traceEarthquake Trail at OlemaA classic beachStinson Beach and BolinasA secretive townBolinas from Stinson BeachMind the gapView South from Stinson Beach
1906 epicenter in mid distanceView North from Mussel RockSan Mateo Peninsula SegmentOn a hazy dayView North from Los Trancos RidgeFollow the yellow stake lineEarthquake Trail at Los Trancos Ridge
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