1 / 14

Kinematic ruptures on faults with multiple segments

Kinematic ruptures on faults with multiple segments. Chen Ji, UCSB. Most kinematic models don’t include multiple segments because. Fault geometry is not very clear. Observations can’t constrain. 1992 Landers Earthquake. Wald & Heaton, 1994, BSSA. 1992 Landers Earthquake

kirby
Download Presentation

Kinematic ruptures on faults with multiple segments

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Kinematic ruptures on faults with multiple segments Chen Ji, UCSB

  2. Most kinematic models don’t include multiple segments because • Fault geometry is not very clear. • Observations can’t constrain

  3. 1992 Landers Earthquake Wald & Heaton, 1994, BSSA

  4. 1992 Landers Earthquake [Wald & Heaton, 1994] Rupture velocity drops when rupture meets the “compression” stepover

  5. 1999 Chi-Chi earthquake[Ji et al., 2003] • Seismic moment 2.7 × 1020 Nm. • Average rupture velocity is about 2.0 km/sec. • Average rise time 7.2 sec

  6. Irregular fault surface • Slip distribution shows eastward low slip zones (pointed by arrows) when the fault trace changes directions • The downward extensions of the low slip zones suggest that the surface curvature is a deep-seated feature. Slip distribution

  7. Snapshot North South Dashed contours shows the rupture fronts in every 3 sec if the rupture velocity is 2.1 km/sec.

  8. Rupture propagation in an irregular fault plane North South Rupture velocity drops when rupture meets the “compression” stepover

  9. Rupture turns • The intersection is not normal to the fault strike direction. • Near the “hinge line”, the uplift of the hanging wall will create additional space for extension.

  10. 1999 Hector Mine Earthquake [Ji et al, 2002, BSSA]

  11. 1999 Hector Mine Earthquake [Ji et al, 2002, BSSA]

  12. What is next in finite fault inversion? • good inverse programs. • Good spatial and frequency data coverage • - High rate GPS • Good Green’s functions, 3D structure • Accurate fault geometry, 3D planes

  13. Summary: • Kinematic slip distributions of several large earthquakes support the argument that compression stepovers slow down the rupture propagation. • No clear evidence so far in my study that dilatation stepovers slow down the kinematic rupture.

  14. 2004 Parkfield Earthquake Afterslip 2004 Sumatra-Andaman Earthquake

More Related