ARGO-DAS : SAR measurements on a surface-deployed optical fiber (Argostoli, Greece)

Project description

The ARGO-DAS project involves a series of DAS measurements on an optical fiber deployed on the surface at the Argostoli site, in one of Europe’s most active seismic zones, on a test site instrumented several times in the past by dense arrays and equipped with a permanent vertical antenna since 2015. The idea is to exploit the spatial density of DAS measurements to record, without aliasing, seismic wave fields in a multi-meter to multi-decameter wavelength range corresponding to frequencies of a few Hz to a few tens of Hz, which control the response of buildings in the event of an earthquake. The installation of the fiber on the surface will be coupled with the deployment of low-cost velocimetric sensors of the nodes type to enable the simultaneous measurement of ground deformations and velocities with the spatial resolution of DAS. These data are needed to better understand the composition of wave fields, and to identify the mechanisms responsible for the spatial variability of ground motions in the frequency range that control building response. This request follows a previous BQR-funded project (DAS4SHA), which provided proof of concept that DAS measurements could be exploited in both phase and amplitude in the frequency range of interest to seismic risk.