Injection experiment offers new view of fluid-filled faults

Wed, 02 Sep 2015 11:52:36 -0400

Researchers deployed a new sensor to study the influence of fluid injection on a fault from a tunnel that is part of an underground research facility in southeastern France. Credit: Yves Guglielmi.

Scientists have known since the late 1960s that injecting fluids underground can cause earthquakes if those fluids find their way into slip-prone fault zones. Evidence of fluid-induced quakes has continued mounting in recent years with observations of abnormally high levels of seismicity in the central U.S., coincident with increased injections of wastewater into the ground — mostly related to oil- and gas-mining operations. But understanding the inner workings of fluid-filled faults is challenging because researchers have been limited by how close they can get to study them. Now, a new study is offering a glimpse into the future of induced-seismicity studies by monitoring fault motions on the spot and in real time.

Blogging On EARTH: Wisconsin's microquake mystery

Wed, 11 Apr 2012 17:41:41 -0400

Downtown Clintonville, Wis.©Royalbroil, Creative Commons Attribution-ShareAlike 3.0 Unported

An EarthScope seismometer similar to those installed in Wisconsin that were used to identify a March 20, 2012 magnitude-1.5 microquake near Clintonville. earthscope.org

Tim Oleson is a staff writer at EARTH. photo courtesy of Dave Clark

On the list of earthquake-prone states, Wisconsin does not rank highly. The largest known earthquake in the state (or at least the suspected largest quake given that its magnitude is not well established) occurred somewhere south of Milwaukee on May 6, 1947, with an intensity estimated as high as “V” (or 5) on the Modified Mercalli intensity scale — which is distinct from the moment magnitude scale customarily used to indicate earthquake severity (moment magnitude is often used interchangeably with the Richter Scale, although the two are different and the latter is no longer conventionally used by seismologists) — meaning it shook windows and caused minor damage in nearby areas.

Microquake on EARTH Magazine

Injection experiment offers new view of fluid-filled faults

Blogging On EARTH: Wisconsin's microquake mystery