Moment‐duration scaling of Low‐Frequency Earthquakes in Guerrero, Mexico
Name
Farge_etal_GRL2020.pdf
Description
Accepted version
Size
6.23 MB
Format
Unknown
Checksum (MD5)
33692aca4b48d05f24b3a4263ad6368d
Author(s)
Farge, Gaspard
Shapiro, Nikolaï M
Frank, William B
Date Issued
2020
Journal
Journal of Geophysical Research: Solid Earth
Publisher
American Geophysical Union (AGU)
Version
Author's final manuscript
Abstract
© 2020. American Geophysical Union. All Rights Reserved. Low-frequency earthquakes (LFEs) are detected within tremor, as small, repetitive, impulsive low-frequency (1–8 Hz) signals. While the mechanism causing this depletion of the high-frequency content of their signal is still debated, this feature may indicate that the source processes at the origin of LFEs are different from those for regular earthquakes. Key constraints on the LFE-generating physical mechanisms can be obtained by establishing scaling laws between their seismic moment and source durations. Here we apply a simple spectral analysis method to the S waveforms of LFEs from Guerrero, Mexico, to measure their seismic moments and corner frequencies, a proxy to source duration. We find characteristic values of M0∼3×1012 N.m (Mw∼2.3) and fc∼3.0 Hz with the corner frequency very weakly dependent on the seismic moment. This moment-duration scaling observed for Mexican LFEs is similar to one previously reported in Cascadia and is very different from the established one for regular earthquakes. This suggests that they could be generated by sources of nearly constant size with strongly varying intensities. LFEs do not exhibit the self-similarity characteristic of regular earthquakes, suggesting that the physical mechanisms at their origin could be intrinsically different.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1029/2019JB019099
