Comparing Seismicity-Inferred Fault Structures to Local Basement Fault Structures in Oklahoma

Date: 4/26/2019

Time: 06:00 PM

Room: Fifth Avenue

The vast majority of seismicity that north central Oklahoma has experienced since 2009 has occurred in the upper portion of the basement. Basement fault structure, however, remains poorly understood on a regional basis. Recent relocation studies have found that earthquake clusters very rarely correlate with faults mapped in the overlying stratigraphic sequence; this implies a distinct difference in structural style between the sedimentary cover and the basement, and that the most significant seismic hazard currently exists on unknown faults. Given the importance of basement structure to seismic hazard in the region, correlating fault structures inferred from spatiotemporal clustering of seismicity to structures derived from other geophysical techniques (e.g., potential field and subsurface imaging) may prove to be a useful tool for corroborating fault structures. These structures could then be incorporated into seismic hazard maps with more confidence, particularly in areas where seismicity has yet to migrate to. Here, we test this hypothesis by systematically comparing high-precision earthquake relocations to a variety of other basement fault data on a local basis in Oklahoma.

Presenting Author: Tyler J. Tripplehorn

Authors