Ocean-bottom seismology

The ocean floor represents the next frontier for seismic studies of Earth structures using broadband ocean-bottom seismograph (OBS) stations. These stations have the advantage of being able to passively record full wave fields from distant earthquakes at a large bandwidth (~100 sec to ~100 Hz) and thus image deep crust and mantle structures, complementing acoustic hydrophone lines used in active source studies of shallow structure. Recording ground motion on the seafloor is particularly important to provide adequate coverage for global and regional studies of Earth structure, given that oceans cover 70% of the Earth surface. In anticipation of an increase in OBS station deployment and data sets, our group is: 1) implementing open-source software programs (see OrientPy and OBStools) to facilitate the use of broadband OBS data; and 2) using these techniques to study the offshore structure of tectonic plate boundaries that are responsible for large destructive earthquakes.

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Pascal Audet
Professor of Geophysics & University Research Chair

Publications

Shear‐wave velocity structure of sediments on Cascadia's continental margin from probabilistic inversion of seafloor compliance data

Several seismic techniques, both passive and active, exist for estimating the shear-wave velocity Vs structure of shallow sedimentary …

Probabilistic inversion of seafloor compliance for oceanic crustal shear velocity structure using mixture density neural networks

Measurements of various physical properties of oceanic sediment and crustal structures provide insight into a number of geological and …

Fluid pressure and shear zone development over the locked to slow slip region in Cascadia

At subduction zones, the deep seismogenic transition from a frictionally locked to steady sliding interface is thought to primarily …

Receiver functions using OBS data: promises and limitations from numerical modelling and examples from the Cascadia Initiative

The expanding fleet of broad-band ocean-bottom seismograph (OBS) stations is facilitating the study of the structure and seismicity of …