A Probabilistic Tremor Location Method

Abstract A method to locate tremor with an unclear onset is introduced. The method maps envelopes of cross‐correlated records from pairs of seismographs to signal likelihoods using Bayes' theorem. The likelihood time series are then back projected to obtain likelihoods of source location in spa...

Full description

Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Ka Lok Li, Olafur Gudmundsson
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2020
Subjects:
Online Access:https://doi.org/10.1029/2019GL085538
https://doaj.org/article/a9838a61ffa246d99d64324a52110282
Description
Summary:Abstract A method to locate tremor with an unclear onset is introduced. The method maps envelopes of cross‐correlated records from pairs of seismographs to signal likelihoods using Bayes' theorem. The likelihood time series are then back projected to obtain likelihoods of source location in space. Assuming that information derived from different station pairs is independent, the joint likelihood for all station pairs is the product of all individual station pair likelihoods. Its peak and spread give the most probable source location and its uncertainty. Robustness of the method has been evaluated with synthetic tests. The method recovers true location within 0.5 km with realistic noise characteristics in synthetic data. Uncertainty estimates are consistent with location deviations for sources inside the seismic network. When applied to real data from Katla and Eyjafjallajökull volcanoes in southern Iceland, their likely tremor source is also recovered within 1 km.