Oceanic high-frequency global seismic wave propagation with realistic bathymetry

Journal article

Abstract:: We present a new approach to simulate high-frequency seismic wave propagation in and under the oceans. Based upon AxiSEM3D (Leng et al. 2019), this method supports a fluid ocean layer, with associated water-depth phases and seafloor topography (bathymetry). The computational efficiency and flexibility of this formulation means that high-frequency calculations may be carried out with relatively light computational loads. A validation of the fluid ocean implementation is shown, as is an evaluation of the oft-used ocean loading formulation, which we find breaks down at longer periods than was previously believed. An initial consideration of the effects of seafloor bathymetry on seismic wave propagation is also given, wherein we find that the surface waveforms are significantly modified in both amplitude and duration. When compared to observed data from isolated island stations in the Pacific, synthetics which include a global ocean and seafloor topography appear to more closely match the observed waveform features than synthetics generated from a model with topography on the solid surface alone. We envisage that such a method will be of use in understanding the new and exciting ocean-bottom and floating seismometer datasets now being regularly collected.

Files:: preprint copy.pdf

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Language:: English
Keywords:: FFR

theoretical seismology

oceans

numerical modelling

wave propagation

computational seismology

guided waves
Pubs id:: 1107111
Local pid:: pubs:1107111
Deposit date:: 2020-05-27

Copyright holder:: Fernando, B et al.
Rights statement:: © The Author(s) 2020. Published by Oxford University Press on behalf of The Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model.
Notes:: This is the accepted manuscript version of the article. The final version is available online from Oxford University Press at: https://doi.org/10.1093/gji/ggaa248

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