Urban Seismic Site Characterization by Fiber-Optic Seismology

This is a Preprint and has not been peer reviewed. The published version of this Preprint is available: https://doi.org/10.1029/2019JB018656.

Downloads

Download Preprint

Authors

Zack Spica , Mathieu Perton, Eileen R Martin, Biondo Biondi, Gregory Beroza

Abstract

Accurate ground-motion prediction requires detailed site effect assessment, but in urban areas where such assessments are most important, geotechnical surveys are difficult to perform, limiting their availability. Distributed acoustic sensing (DAS) offers an appealing alternative by repurposing existing fiber-optic cables, normally employed for telecommunication, as an array of seismic sensors. We present a proof-of-concept demonstration by using DAS to produce high-resolution maps of the shallow subsurface with the Stanford DAS array, California. We describe new methods to assess H/V spectral ratio -- a technique widely used to estimate the natural frequency of the soil -- and to extract Rayleigh-wave dispersion curves from ambient seismic field. These measurements are jointly inverted to provide models of shallow seismic velocities and sediment thicknesses above bedrock in central campus. The good agreement with an independent survey validates the methodology and demonstrates the power of DAS for microzonation.

DOI

https://doi.org/10.31223/osf.io/j8vn9

Subjects

Earth Sciences, Geophysics and Seismology, Physical Sciences and Mathematics

Keywords

Seismology, DAS, fiber-optic, microzonation, site effect

Dates

Published: 2019-07-16 19:47

Last Updated: 2020-02-13 03:22

Older Versions
License

GNU Lesser General Public License (LGPL) 2.1

Add a Comment

You must log in to post a comment.


Comments

There are no comments or no comments have been made public for this article.