Urban Distributed Acoustic Sensing Using In-Situ Fibre Beneath Bern, Switzerland

Session: Photonic Seismology [Poster]
Type: Poster
Date: 4/30/2020
Time: 08:00 AM
Room: Ballroom
Description: 

Distributed Acoustic Sensing (DAS) technology allows for the effective use of fibre optic cables as dense seismic arrays in otherwise inaccessible locations. While traditional seismological methods are often limited by infrastructure in urban environments, we are able to use DAS technology with existing, in-situ fibre optic cables for seismic observation beneath urban areas. In turn, this can improve our understanding of the shallow Earth structure of the region and therefore lead to greater understanding of the risks posed locally by natural hazards.

In collaboration with the SWITCH foundation, seismic data was collected over a period of two weeks using existing, in-situ fibres beneath Bern, Switzerland. This data covers a distance of 6 km with a spatial resolution of 2 m and allows for the visualisation of both anthropogenic noise sources and the resulting seismic waves as they propagate through the subsurface.

We evaluate the nature of the signals captured and the consistency of data quality by analysing the data in the time and frequency domain. Both noise correlations and deterministic signals excited by traffic can be used to constrain the local velocity structure.

Initial results confirm the utility of DAS with existing fibre infrastructure and demonstrate potential for using DAS technology to perform seismic tomography and hazard analysis in urban environments.

Presenting Author: Patrick Paitz

Authors