Bridging the gap between low-frequency and very-low-frequency earthquakes

Distribution of low-frequency earthquakes accompanying the very low frequency earthquakes along the Ryukyu Trench

This study investigated the activity and distribution of low-frequency earthquakes (LFEs) accompanying the very low frequency earthquakes (VLFEs) in the central and southern Ryukyu Trench. This investigation was based on shortperiod seismometer waveforms obtained by the Japan Meteorological Agency from April 2004 to December 2015. The LFEs were detected using the Envelope Correlation Method, an...

Low-Frequency Properties of Intermediate-Focus Earthquakes

Intermediate-focus earthquakes are known to show features such as nondouble-couple focal mechanisms that indicate source complexities. To characterize these features, we have systematically studied the low-frequency radiation from 108 intermediate-focus earthquakes recorded by high-performance seismic networks from 1989–1997 whose total moment was 3 10 N m. We determined frequency-dependent foc...

The trigger mechanism of low-frequency earthquakes on Montserrat

A careful analysis of low-frequency seismic events on Soufrièere Hills volcano, Montserrat, points to a source mechanism that is non-destructive, repetitive, and has a stationary source location. By combining these seismological clues with new field evidence and numerical magma flow modelling, we propose a seismic trigger model which is based on brittle failure of magma in the glass transition....

The evolving interaction of low-frequency earthquakes during transient slip

Observed along the roots of seismogenic faults where the locked interface transitions to a stably sliding one, low-frequency earthquakes (LFEs) primarily occur as event bursts during slow slip. Using an event catalog from Guerrero, Mexico, we employ a statistical analysis to consider the sequence of LFEs at a single asperity as a point process, and deduce the level of time clustering from the s...

Very-low-frequency saucers observed on DEMETER