A cross-section of a portion of the Cascadia subduction zone. Credit: USGS
Excerpts;
Natural fracking may be to blame for weird “slow” earthquakes that last for hours to days, a new study suggests.
Oil and gas fracking involves cracking open rocks using water laced with sand and chemicals, pumped underground at high pressure. Now, seismic evidence from the Cascadia subduction zone leads researchers to suggest a similar process takes place deep on the zone’s massive fault, generating slow earthquakes…
Read Full Article, LiveScience
Does fracking cause quakes? California needs to know; Los Angeles Times
Induced Earthquakes, Earthquakes Hazard Program, USGS (April 2014)
A team of USGS scientists led by Bill Ellsworth analyzed changes in the rate of earthquake occurrence using large USGS databases of earthquakes recorded since 1970. The increase in seismicity has been found to coincide with the injection of wastewater in deep disposal wells in several locations, including Colorado, Texas, Arkansas, Oklahoma and Ohio. Much of this wastewater is a byproduct of oil and gas production and is routinely disposed of by injection into wells specifically designed and approved for this purpose. Hydraulic fracturing, commonly known as “fracking,” does not appear to be linked to the increased rate of magnitude 3 and larger earthquakes. Although wastewater injection has not yet been linked to large earthquakes (M6+), scientists cannot eliminate the possibility…
California City Becomes First To Vote To Ban Fracking, (04-25-2014)
Sand mining Is Booming Along With Fracking, My San Antonio News (Uploaded 09-27-2011)
Fracking, the latest craze in the quest to produce oil and gas, has been blamed for environmental problems ranging from flammable tap water to minor earthquakes. Now a new risk is emerging: sand mining. To squeeze hydrocarbons out of shale through hydraulic fracturing of the rock, the process known as fracking, producers need to pump an enormous amount of sand into the ground…
