Paleoseismic Evidence for the 21 April 1918 Mw 6.9 Surface Rupture of the Northern Clark Strand of the Central San Jacinto Fault, California

James B. Salisbury, Thomas K. Rockwell, & Michael T. Buga

Published March 22, 2017, SCEC Contribution #7068

In this study we present results of a new paleoseismic investigation in the South Fork Wilderness ~7 km SE of Blackburn Canyon, ~5 km NW of Hog Lake near Anza, California that demonstrates that the northern Clark fault has ruptured twice in the past 300 years. These new results corroborate previously-made interpretations that were based solely on surficial geomorphology -- that the northern Clark fault (with a recurrence interval of ~100 years) ruptured in both the November 1800 and 1918 earthquakes, and shows that the northern Clark fault has a more frequent recurrence interval than the central and southern Clark fault.

Key Words
Surface Rupture, 1918, San Jacinto fault, Clark fault

Citation
Salisbury, J. B., Rockwell, T. K., & Buga, M. T. (2017). Paleoseismic Evidence for the 21 April 1918 Mw 6.9 Surface Rupture of the Northern Clark Strand of the Central San Jacinto Fault, California. Bulletin of the Seismological Society of America, 107(2), 1027-1032. doi: 10.1785/0120160026.