ch 3: characterization of the sfbr earthquake sources working group on california earthquake...
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Ch 3: Characterization of the SFBR Earthquake
SourcesWorking Group on California
Earthquake Probabilities, 2002
Overview
Fault SegmentationRupture Sources &
ScenariosGeologic Slip RatesPrevious EarthquakesFault Area
Area covered by report
Fault Segments
the shortest section considered capable of repeatedly rupturing to produce large earthquakes
criteria: kinematic & dynamickinematic: geometry, structuredynamic: rupture length, displacement
of previous eqs, timing, changes in slip/creep rates, microearthquakes
Ruptures
rupture source: single or combination of adjacent fault segments; floating eq
rupture scenario: combination of rupture sources that describe mode of failure of the entire fault during one eq cycle
rupture model: weighted combinations of the fault-rupture scenarios
Hayward-Rogers Creek Segments
140 km long 3 segments: 9±2
RC: 8.4±2, 235-387 HN: 10±1, 270-710 HS: 7-10, 150-250 N,
130±40 S Tule Pond creep 4-6
change in timing constraint from previous reports
Rupture Model Construction
San Andreas Segments
~260
~300
~150
San Gregorio Segments
Calaveras Fault Segments
Green Valley & Concord Faults
Greenville Fault Segments
Segment Dimensions
Follow-up Papers Segall, P., and Lisowski, M., 1990, Surface displacements in the 1906 San
Francisco and 1989 Loma Prieta earthquakes: Science, v. 250, no. 4985, p. 1241-1244.
Schwartz, D.P., Pantosti, D., Okumura, K., Powers, T., and Hamilton, J., 1998, Paleoseismic investigations in the Santa Cruz Mountains: Implications for the recurrence of large magnitude earthquakes on the San Andreas Fault: Journal of Geophysical Research, v. 103, p. 17,985-18,001.
Thatcher, W., Marshall, G., and Lisowski, M., 1997, Resolution of fault slip along the 470-km- long rupture of the great 1906 San Francisco earthquake: Journal of Geophysical Research, v. 102, no. B3, p. 5353-5367.
Lettis, W., 2001, Late Holocene behavior and seismogenic potential of the Hayward-Rodgers- Creek fault system in the San Francisco Bay area, California: Calif. Geol. Surv. Bulletin, v. 210, p. 167-178.
C. Goldfinger et al., Rupture lengths and temporal history of significant earthquakes on the offshore and north coast segments of the Northern San Andreas Fault based on turbidite stratigraphy, Earth Planet. Sci. Lett. (2006).