microseismic

/ˌmaɪkroʊˈsaɪzmɪk/
adjective
  1. Relating to very small earthquakes or ground vibrations that are not felt by people.
    • Engineers use microseismic data to check for cracks in dams.
    • The region has low microseismic risk, so buildings do not need special earthquake protection.
    • The microseismic activity was monitored by sensors placed deep underground.