Crustal Low-Frequency Earthquakes

  • Tsuchiyama, A., Taira, T. A., Nakajima, J., & Bürgmann, R. (2022). Emergence of Low‐Frequency Aftershocks of the 2019 Ridgecrest Earthquake Sequence. Bulletin of the Seismological Society of America. (https://doi.org/10.1785/0120210206)

Low-frequency earthquakes (LFEs) have larger amplitudes in the lower frequency range than regular earthquakes, possibly suggesting a slow rupture process.

Although LFEs have been observed in plate boundaries and volcanic regions, we still do not know whether LFEs essentially have a similar mechanism to regular earthquakes, or follow a unique triggering process in particular conditions.

Tsuchiyama et al. (2022)

My research group worked to identify LFE-like earthquakes in the 2019 Ridgecrest sequences. Based on their definition and thresholds, Tsuchiyama et al. (2022) show that crustal LFEs can be identified in the aftershock sequences of the 2019 Ridgecrest event. This observation could be explained by either fluid re-distribution or local attenuation caused by the mainshock, or the combination of both hypotheses.