Using Noise Correlation to Improve the 3D Seismic Velocity Model of the Seattle Basin

Date: 4/24/2019

Time: 06:00 PM

Room: Grand Ballroom

The Seattle sedimentary basin beneath Seattle is known to significantly amplify long period ground motions. The basin has been characterized by past seismic and other geophysical experiments. The goal of the Seattle Urban eXperiment (SUX) is to use ambient noise cross-correlation of broadband data recorded along receiver-receiver lines throughout the city to understand the basin structure in areas not previously studied and help guide larger experiments in the city scheduled later this year. Ambient noise cross-correlation can be used to extract Green's functions between two receivers since the cross-correlation functions are similar to surface waves excited by earthquakes. Analysis of the surface wave dispersion is used to generate a near-surface velocity model. Our experiment currently uses data recorded by six portable broadband stations as well as existing broadband stations sited in the city. Only a few weeks of data are needed for stable correlelegrams after which the stations are moved. As long as the portable instruments are not needed for other purposes, we plan on continuing to collect data throughout the Puget lowlands and will potentially target other structures such as the Tacoma basin.

Presenting Author: Alex Hutko

Authors