Modulation of Seismic Radiation by Fault-Scale Geology of the 2016 Mw 6.0 Shallow Petermann Ranges Earthquake (PRE) in Central Australia

Mo，Tao1,2; Attanayake，Januka1

2023-04-01

10.1785/0120220137

Bulletin of the Seismological Society of America   Impact Factor & Quartile

0037-1106

1943-3573

Understanding the modulatory influence of fault-scale geology on seismic behavior of earthquake faults is central to determining the physics of faulting and seismic hazard analysis. Although laboratory experiments predict that seismic parameters can be modulated by fault-scale geology, there is scant empirical evidence of this process at field scale due largely to a lack of shallow earthquakes of which causative faults can be mapped to known bedrock structure. The 20 May 2016 M 6 Petermann Ranges earthquake (PRE) is the best-recorded continental event in Australia to date, and it is an excellent candidate to investigate the possible link between seismic parameters and fault-scale geology as its causative fault has previously been linked to known bedrock structure using distributions of aftershocks, surface observations, and geophysical mapping. In this study, we analyze strain energy partitioning of PRE by determining seismic radiation efficiency (0.31) and apparent stress (0.34 MPa) together with previously estimated stress drop (2.2 MPa) and find that the combination of these macroseismic parameters deviates from that expected of a shallow immature fault in intraplate continental regions typically character-ized by large recurrence intervals. It instead appears to have mimicked a mature fault, which we attribute to the characteristics of the causative fault confined to mechanically weaker, phyllosilicate-rich foliations of the bedrock that have anomalously lower fracture energy. Therefore, PRE rupture suggests the presence of a spectrum of shallow (< 20 km) fault slip behavior modulated by fault-scale geology.

SCI

English

Others

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:000962855000004

SEISMOLOGICAL SOC AMER

GEOSCIENCES

2-s2.0-85152039660

Scopus

1.School of Geography,Earth and Atmospheric Sciences,The University of Melbourne,Parkville,Australia
2.Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen,China

Mo，Tao,Attanayake，Januka. Modulation of Seismic Radiation by Fault-Scale Geology of the 2016 Mw 6.0 Shallow Petermann Ranges Earthquake (PRE) in Central Australia[J]. Bulletin of the Seismological Society of America,2023,113(2):604-612.

Mo，Tao,&Attanayake，Januka.(2023).Modulation of Seismic Radiation by Fault-Scale Geology of the 2016 Mw 6.0 Shallow Petermann Ranges Earthquake (PRE) in Central Australia.Bulletin of the Seismological Society of America,113(2),604-612.

Mo，Tao,et al."Modulation of Seismic Radiation by Fault-Scale Geology of the 2016 Mw 6.0 Shallow Petermann Ranges Earthquake (PRE) in Central Australia".Bulletin of the Seismological Society of America 113.2(2023):604-612.