Earth Sciences

Multi-phase seismic source imprint of tropical cyclones

L. Retailleau and L. Gualtieri

Ocean storms are more than just dramatic weather events; they generate seismic signals that can reveal insights about our planet. This fascinating study by Lise Retailleau and Lucia Gualtieri investigates how Typhoon Ioke produced seismic waves during its transition, highlighting crucial variations in source locations essential for understanding ocean dynamics and noise imaging.... show more

Abstract

The coupling between the ocean activity driven by winds and the solid Earth generates seismic signals recorded by seismometers worldwide. The 2–10 s period band, known as secondary microseism, represents the largest background seismic wavefield. While moving over the ocean, tropical cyclones generate particularly strong and localized sources of secondary microseisms that are detected remotely by seismic arrays. We assess and compare the seismic sources of P, SV, and SH waves associated with typhoon loke (2006) during its extra-tropical transition. To understand their generation mechanisms, we compare the observed multi-phase sources with theoretical sources computed with a numerical ocean wave model, and we assess the influence of the ocean resonance (or ocean site effect) and coastal reflection of ocean waves. We show how the location and lateral extent of the associated seismic source is period- and phase-dependent. This information is crucial for the use of body waves for ambient noise imaging and gives insights about the sea state, complementary to satellite data.

Publisher

Nature Communications

Published On

Apr 06, 2021

Authors

Lise Retailleau, Lucia Gualtieri

DOI

https://doi.org/10.1038/s41467-021-22231-y