Performance and outlook for the SADAR array network at the Newell County facility

Since installation in November 2021, a sparse network of SADAR compact volumetric arrays has been continuously and persistently acquiring data for passive microseismic monitoring of the Newell County Facility (NCF) CO2 storage pilot site. This report summarises several fundamental results from a year of continuous monitoring of the NCF using the SADAR permanent array network, including an updated seismic velocity model determined from ground truth calibration events, the observed seismicity derived from the curated year-long bulletin, and quantified estimates of system performance. In particular, the bulletin includes more than 560 analyst-verified located events excluding those at the surface, with at least 200 considered to be well-located. We have documented noise reduction provided by coherent processing of SADAR array data in excess of 30 dB compared to surface sensors and signal-to-noise ratio (SNR) improvements up to 20 dB compared to single channels. Combining the bulletin information and performance measurements, we estimate magnitude of completeness Mc ≈ −2.5 Mw, and an event-to-receiver range for locatable events of at least 600 m from individual arrays. We conclude with a look at continuing and planned projects using the SADAR network at the NCF including tests of active source acquisition.