Seismic events triggered by UK fracking
A 0.5ML event is enough to stop fracking operations under the UK traffic light system, while in Oklahoma, where most oil & gas industry-related seismic events have occurred, the threshold has been set at 2.5ML.
Operator must suspend injection, reduce pressure and monitor seismicity and ground motion for any further events before potentially resuming.
0.0 - <0.5
Injection proceeds with caution, possibly at reduced rates. Monitoring is intensified.
Injection proceeds as planned.
Operator must pause operations for at least six hours.
Operators must take unspecified actions.
Source: UK OGA and Oklahoma Corporation Commission