PALEOSEISMICITY OF THE NORTH BRANCH OF THE NEWPORT-INGLEWOOD FAULT ZONE IN HUNTINGTON-BEACH, CALIFORNIA, FROM CONE PENETROMETER TEST DATA

Citation
Lb. Grant et al., PALEOSEISMICITY OF THE NORTH BRANCH OF THE NEWPORT-INGLEWOOD FAULT ZONE IN HUNTINGTON-BEACH, CALIFORNIA, FROM CONE PENETROMETER TEST DATA, Bulletin of the Seismological Society of America, 87(2), 1997, pp. 277-293
Citations number
26
Categorie Soggetti
Geochemitry & Geophysics
ISSN journal
00371106
Volume
87
Issue
2
Year of publication
1997
Pages
277 - 293
Database
ISI
SICI code
0037-1106(1997)87:2<277:POTNBO>2.0.ZU;2-2
Abstract
Application of cone penetrometer testing (CPT) is a promising method f or studying subsurface fault zones in stratified, unconsolidated sedim ent where trenching is not feasible. Analysis of data from 72 CPTs, sp aced 7.5 to 30.0 m apart, and 9 borings indicates that the North Branc h fault, the active strand of the Newport-Inglewood fault zone (NIFZ) in Huntington Beach, has generated at least three and most likely five recognizable surface ruptures in the past 11.7 +/- 0.7 ka. Additional smaller earthquakes similar to the M-w 6.4 1933. Long Beach earthquak e may also have occurred but would not be recognizable with this metho d. The minimum right-lateral Holocene slip rate of the NIFZ in the stu dy area is estimated to be 0.34 to 0.55 mm/yr. The actual slip rate ma y be significantly higher.