Model for triggering of non-volcanic tremor by earthquakes

TL;DR

This paper presents a fault response model explaining how distant earthquakes trigger non-volcanic tremor, emphasizing frequency content consistency and the absence of impulsive phases, linking tremor to fault dynamics rather than source specifics.

Contribution

The authors adapt a plate dynamics model to describe tremor triggering, highlighting its internal fault response mechanism and frequency characteristics independent of source nature.

Findings

Tremor frequency content is largely independent of the triggering source.

The model predicts tremor radiation within a specific frequency range based on fault parameters.

Tremor lacks a clear impulsive phase, unlike typical earthquakes.

Abstract

There is evidence of tremor triggering by seismic waves emanating from distant large earthquakes. The frequency content of both triggered and ambient tremor are largely identical, suggesting that this property does not depend directly on the nature of the source. We show here that the model of plate dynamics developed earlier by us is an appropriate tool for describing tremor triggering. In the framework of this model, tremor is an internal response of a fault to a failure triggered by external disturbances. The model predicts generation of radiation in a frequency range defined by the fault parameters. Thus, although the amplitude and duration of a tremor burst may reflect the "personality" of the source, the frequency content does not. The model also explains why a tremor has no clear impulsive phase, in contrast to earthquakes. The relationship between tremor and low frequency earthquakes is discussed.