Publication Date:
2012-06-01
Description:
The great Fort Tejon earthquake of 1857, with an ∼350-km-long surface rupture, was the most recent major earthquake along the south-central San Andreas fault (SAF). Prior reconstruction of its surface-slip distribution and reconstruction of preceding earthquakes along the 1857 rupture trace have contributed to formulation of the characteristic earthquake (CEM) and uniform-slip models (USM) for earthquake recurrence that find wide application in seismic hazard assessment and earthquake forecasting. We used the high-resolution B4 light detection and ranging (LiDAR) topographic data set—sufficient for depiction of meter-scale tectonic landforms—to reevaluate the distribution of surface displacement along the 1857 rupture trace. We present ∼450 offset measurements with displacements below 60 m, increasing observation density relative to previous studies by a factor of 2. Our results show that the 1857 earthquake had overall an average displacement below 3.5 m with 4–6 m released along the northwestern half of the rupture. Its along-fault slip distribution is smooth at 〉10-km length scales. At
Print ISSN:
0037-1106
Electronic ISSN:
1943-3573
Topics:
Geosciences
,
Physics
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