UPDATE: Humans can cause earthquakes

Right on! We're right up there with the gods of Olympus in rocking the planet
that we live on, for now.

Unfortunately, if we F%^&&*k it all up, we don't have the means to get to the next
habitable planet, but that may be a job for NASA.

We can seed clouds, and we can put fish genes in a tomato.

more later

checkitout: from The Big Picture
Human Activity Can Cause Earthquakes

By Washingtons Blog - August 25th, 2011, 5:44AM
It’s Official: Human Activity Can Cause Earthquakes
Human Activity Is Officially Acknowledged to Cause Earthquakes

The United States Geological Survey is America’s official expert on earthquakes. It’s the Federal agency charged with monitoring, reporting on, researching and stressing preparedness for earthquakes.

So I was surprised to read the following statement by the USGS:

Earthquakes induced by human activity have been documented in a few locations in the United States, Japan, and Canada. The cause was injection of fluids into deep wells for waste disposal and secondary recovery of oil, and the use of reservoirs for water supplies. Most of these earthquakes were minor. The largest and most widely known resulted from fluid injection at the Rocky Mountain Arsenal near Denver, Colorado. In 1967, an earthquake of magnitude 5.5 followed a series of smaller earthquakes. Injection had been discontinued at the site in the previous year once the link between the fluid injection and the earlier series of earthquakes was established. (Nicholson, Craig and Wesson, R.L., 1990, Earthquake Hazard Associated with Deep Well Injection–A Report to the U.S. Environmental Protection Agency: U.S. Geological Survey Bulletin 1951, 74 p.)

Injection Wells Can Induce Earthquakes

The New York Times noted in February:

Researchers with the Arkansas Geological Survey say that while there is no discernible link between earthquakes and gas production, there is “strong temporal and spatial” evidence for a relationship between these quakes and the injection wells.

For decades, scientists have been researching induced seismicity, or how human activity can cause earthquakes. Such a link gained attention in the early 1960s, when hundreds of quakes were recorded in Colorado a few years after the Army began injecting fluid into a disposal well near the Rocky Mountain Arsenal.

Lawrence Berkeley Laboratory points out:

Induced seismicity [i.e. earthquakes] in oil and gas production has been observed ever since the 1930s, i.e., ever since large scale extraction of fluids occurred. The most famous early instance was in Wilmington, California, where the oil production triggered a series of damaging earthquakes. In this instance the cause of the seismicity was traced to subsidence due to rapid extraction of oil without replacement of fluids.

In the last decade a number of examples on earthquake activity related to oil and gas production as well as injection of liquids under high pressure have been observed, although not with as serious consequences as for Wilmington. Almost all induced seismicity associated with petroleum extraction can be traced to either fluid injection or extraction. In some recent cases injection of produced water (excess water extracted during oil and gas extraction) has produce significant seismic activity. Examples are in Colorado and Texas where gas and oil production yield large volumes of water that must be put back underground. In some cases the water cannot be put back exactly where it was produced and over pressurization of the water causes induced seismicity.

Lawrence Berkeley Lab provides details:

Fluid pressures play a key role in causing seismicity. Explained in simple terms, fluids can play a major role in controlling the pressures that are acting on the faults. The fluid pressure in the pores and fractures of the rocks is called the pore pressure.

Injecting fluids into the subsurface is one way of increasing the pore pressure and thus allowing the faults and fractures to “fail” more easily, thus inducing an earthquake.

That is why in many cases induced seismicity is caused by injecting fluid into the subsurface or by extracting fluids at a rate that causes subsidence and/or slippage along planes of weakness in the earth. Figure 2 is an example of induced seismicity being caused by water injection. Figure 2 is a cross section of the earth showing the location of the earthquakes (green dots), the locations of injection wells (thick blue lines) and production wells (thin lines, these wells extract fluid). Note the large number of events associated with the injection wells.....