The 2021 Tower Lake Dense Array Experiment for High-Resolution Microseismicity Monitoring During Hydraulic Fracturing

The rapid expansion of hydraulic fracturing (HF) operations in the Western Canada Sedimentary Basin (WCSB) has significantly altered regional seismicity patterns, leading to an increased frequency of injection-induced earthquakes (IIE). While existing regional networks provide robust monitoring for moderate-magnitude events, they often lack the resolution required to characterize small-magnitude seismicity and detailed rupture processes. To address this, a collaborative research project was launched to deploy the Tower Lake Dense Array (TLDA), a temporary high-resolution seismic network in northeast British Columbia. The TLDA (network code 4R) consisted of 36 stations, comprising 33 strong motion and 3 weak motion sensors, deployed in a 6 × 6 km grid with approximately 1 km inter-station spacing. Operating from January to June 2021, the array utilized novel high-resolution sensors, featuring 24-bit digitization, real-time wireless transmission, and GPS time synchronization. Technical validation using teleseismic and local injection-induced events demonstrates that the array provides high-fidelity waveforms across a broad frequency band. Analysis identified a consistent 180^∘ polarity inversion in the vertical channels of the TLDA that must be corrected. This paper introduces the publicly available TLDA dataset and evaluates its operational performance.