This poster shows a comparison of 1000 ft deep borehole Silicon Audio 203-60 sensor with geophones and a fiber distributed acoustic sensor (DAS).

We especially liked the quote below:

For microearthquakes, assuming frequency range of above 2 Hz, the SA-ULN sensor would be the ideal choice.

Correa, et al. (2020) Exploring the limits of fiber-optic sensing in Cascadia: Borehole passive seismic monitoring using co-located DAS, low noise optical accelerometers, and geophones, Abstract 759800

AGU Fall Meeting 2020 (confex.com)https://agu.confex.com/agu/fm20/meetingapp.cgi/Paper/759800