Radon transform-based detection of microseismicity on DAS networks: A case study from Antarctica

Seismic arrays deployed using DAS generally suffer from a poorer SNR than those using conventional seismometers or geophones, however their high spatial resolution provides opportunities to supress noise and enhance coherent signals. Using a localised Radon transform-based detection method, we exploit the spatial resolution of DAS to identify low amplitude arrivals. We develop this approach using data acquired at the Rutford Ice Stream, Antarctica, where naturally occurring microseismicity is a regular occurrence due to high flow rates of the glacier. During January 2020 both linear and triangular arrangements of fibreoptic cable were deployed to recorded icequakes originating from the base of the glacier, and these were complimented by a network of 3-component geophones. Using a 6hr subset of this dataset we show that the DAS network can achieve a higher detection rates than the geophone network when Radon detection methods are employed. The linear array achieves better detection rates than the triangular array due to is larger spatial coverage, however the one-dimensional nature of the array results in significant ambiguities in event locations.

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