Surface or Shallow Borehole for Induced Seismicity: is This the Question?

Abstract

Should we try to improve surface monitoring array performance by deploying the sensors at the shallow borehole? We show a case where the surface sensor recorded higher signal-to-noise than the shallow borehole sensor. This improvement is limited to a frequency band between 20 Hz and 50 Hz and it is not caused by lack of coupling of the sensor in the shallow borehole. Our explanation is the resonance effect in the near-surface layers which improves detection of microseismic events.