Earthquakes have been linked to hydraulic fracturing. Now researchers at the University of Calgary have found a warning sign to earthquakes caused by fracing, which they say may be able to predict those quakes well before they happen.
The team of seismologists found that, sometimes, fracing can cause layers of rock to slowly slip on a fault —the spot where two tectonic plates come together—leading to enough strain on another section fault to cause it to slip suddenly, causing an earthquake.
Monitoring that creeping slip could provide a warning.
“This really gives us a possibility that there could be a way of monitoring that something is going to occur before the actual earthquake occurs,” Thomas Eyre, the study’s lead author said. “This slip actually initiates tens of hours before the earthquake occurs. So, you’ve got a decent amount of warning time before the earthquake.”
The research offers a possible explanation to why earthquakes shouldn’t be happening in shale, the kind of rock where fracing is taking place. The answer might be that the quake happens at the part of the fault that’s unstable, hundreds of meters away from the fracing zone.
“There are existing techniques that are used to try and manage the risk of induced seismicity,” said co-researcher David Eaton. “What our results indicate is that we might be able to improve on or enhance that monitoring if we could detect this fault creeping effect happening prior to it.”