Seismic Indicators of Fault Maturity

Huiyun Guo, Thorne Lay, & Emily E. Brodsky

Submitted September 11, 2022, SCEC Contribution #12427, 2022 SCEC Annual Meeting Poster #101

Earthquake generating fault systems span a wide range of fault maturity, from evolving segmented fracture systems with minor offsets to strongly localized primary faults with large cumulative offsets. Many large continental strike-slip earthquakes involving fault systems with varying maturity have now been well studied using in situ field observations and seismic and geodetic analysis that characterize their rupture patterns and ground deformations. In this work, we compiled field observations that indicate a wide range of relative fault system maturity for strike-slip faults that have produced more than 30 well-recorded large earthquakes with moment magnitudes, MW ≥ 6.1. We then consider seismological observations for each large event, including radiated seismic energy, aftershock productivity, and rupture velocity, seeking to establish any relationships with the independently assessed relative fault zone maturity determined from geological measurements, such as, cumulative fault offsets and segmentation results. We find, for example, that mature faults tend to have relatively low aftershock productivity and high rupture velocities. This empirical approach is intended to establish whether there are relationships between remote seismological observations and fault system maturity that can help to understand variations in seismic hazard among different fault environments.

Citation
Guo, H., Lay, T., & Brodsky, E. E. (2022, 09). Seismic Indicators of Fault Maturity. Poster Presentation at 2022 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Geology