← Back to Sessions

Shallow Seismicity in Long Beach-Seal Beach Area Detected by Dense Arrays

Session: Seismic Hazard Analysis for Critical Infrastructure [Poster]

Type: Poster

Date: 4/19/2021

Presentation Time: 03:45 PM Pacific

Description: 

The Newport-Inglewood Fault (NIF) in the Long Beach-Seal Beach area was the site of the 1933 Long Beach M6.4 Earthquake, which caused substantial damage. A recent study suggests the NIF penetrates through the Moho into the mantle and splays out into a fairly wide zone above 6 km. This has likely led the seismic hazard in this highly urbanized region to be underestimated. There also appears to be additional unmapped faults in the area.

To investigate the seismic hazard in the Long Beach-Seal Beach area, we use three dense oil exploration arrays covering this region to look for micro-seismicity. Our detection and location results show there is a large number of shallow events that are undetected in the SCSN catalog and recent template-matching studies. These appear to relate to splays of the NIF and other unnamed faults. In the Seal Beach area, these are compared to cross-sections produced by oil industry imaging.

Presenting Author: Yan Yang

Student Presenter: Yes

Authors