Ch 3: Characterization of the SFBR Earthquake Sources

1
Ch 3 Characterization of the SFBR Earthquake
Sources

• Working Group on California Earthquake
  Probabilities, 2002

2
Overview

• Fault Segmentation
• Rupture Sources Scenarios
• Geologic Slip Rates
• Previous Earthquakes
• Fault Area

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Area covered by report
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Fault Segments

• the shortest section considered capable of
  repeatedly rupturing to produce large earthquakes
• criteria kinematic dynamic
• kinematic geometry, structure
• dynamic rupture length, displacement of previous
  eqs, timing, changes in slip/creep rates,
  microearthquakes

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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

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Hayward-Rogers Creek Segments

• 140 km long
• 3 segments 92
• RC 8.42, 235-387
• HN 101, 270-710
• HS 7-10, 150-250 N, 13040 S Tule Pond
• creep 4-6
• change in timing constraint from previous reports

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Rupture Model Construction
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San Andreas Segments
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260
300
150
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San Gregorio Segments
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Calaveras Fault Segments
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Green Valley Concord Faults
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Greenville Fault Segments
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Segment Dimensions
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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).