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2.5 Mile Deep Hole Drilled Into San Andreas Fault
iandoh writes "Cool research: Geologists at Stanford University and the US Geological Survey have drilled a 2.5 mile deep borehole into the San Andreas fault. They've extracted over one ton of rock from 2 miles down, and they'll be installing sensors down the length of the borehole."
Oh, sure, just do his work for him. Why not install some nuclear warheads down there while you're at it.
They've extracted over one ton of rock from 2 miles down, and they'll be installing sensors down the length of the borehole.
I wouldn't want to be the guy who's in charge of monitoring sensory data from something called "the bore hole". that sounds like a really tedious job.
The theory of relativity doesn't work right in Arkansas.
It does seem to be less than the record there. But we can hardly fualt (har har) the team for not digging the full 50 miles to the asthenosphere. :)
Modern oil rigs don't drill into one of the world's largest fault lines. This depth will give a very broad understanding, topologically the distribution of vibration analysis, fracture mechanics, etc., etc.
Models will be developed to study and help with how the Earth expands and contracts.
I feel our economy will be well served by the extra 6 energy.
If your theory is different from practice, then your theory is wrong.
They drilled in a part of the San Andreas fault that creeps and doesn't generate big earthquakes. My take is that they're looking for a lubricant, something that allows the fault to slide. Another possibility would be merely that the fault doesn't have bends or splits in it unlike the faulting at the south end of the San Francisco Bay. The San Andreas fault runs along a chain of mountains south of Silicon Valley and then north through San Francisco, following the coast thereafter, while the Haywood fault runs along the base of mountains east of the Bay area from Milpitas to north of Oakland.
If a lubricant is responsible for the fault creep, there are apparently several possibilities: water, serpentine (which can be formed by weathering or metamorphization of several minerals including olivene/peridot), or talc (formed by serpentine exposed to water). If you have talc, you probably have the other two as well. Serpentine is a bit harder than talc (the latter is soft enough to easily scratch with a fingernail), but both deform easily under pressure. I seem to recall cases where serpentine has "bubbled up" over millions of years through denser rock, acting as a very slow moving fluid.
As I see it, if we can understand how to lubricate faults, then it is possible to not just trigger faults, but also to ease pressure on a fault. Maybe the cost of the materials will make it infeasible, but we can consider it now.
It gets harder and harder to drill deep into the Earth because rocks get softer and softer. Brittle at the surface, rocks become plastic at depth, and the pressure caused by the weight of the overlaying crust--about 52,800 pounds per square inch (3,700 kilograms per square centimeter) at a depth of ten miles (16 kilometers), says drilling consultant William Maurer--collapses deep wells, making further drilling impossible.
Forget thrust, drag, lift and weight. Airplanes fly because of money.
My favored culprit for drastic friction reduction during faulting is lubricating Silica Gel; finely crushed quartz in the active fault zone reacts with water forming fluidic silica gel. There is excellent laboratory evidence of silica gel lubrication in simulated fault zones (see Mineral Gel May Reduce Rock Friction to Zero During Earthquakes, http://www.nsf.gov/news/news_summ.jsp?cntn_id=100325. All that is needed is field evidence, and I think I have it.
In Sid Meier's Alpha Centauri (a spiritual branch from the Civilization series, which I consider better than any of the Civ proper games that followed it), thermal boreholes are terrain improvements that provide +6 energy and minerals (a great deal by the game's standards).
If your theory is different from practice, then your theory is wrong.
Modern oil wells are drilled as deep as 6 miles or more now.
heh,
and modern measures are in metric.
from iopd.og: Hundreds to thousands of small to moderate earthquakes per day are recorded in a typical deep mine; the strongest may reach an intensity of magnitude 5. Given that many of these earthquakes are controlled directly by the mining activity, their location, timing, and magnitude can be forecast, and instruments can be installed at sites where earthquakes of interest are predicted to occur. The mine infrastructure provides access to the earthquakes' source region and allows three-dimensional mapping of the fault zone. It also allows installation of a three-dimensional array of instruments 1-100 m from an anticipated hypocenter to monitor fault activity before, during, and after an earthquake. Most expected earthquakes exhibit a moment-magnitude range (-2 to 4) that bridges the scale gap between laboratory experiments and tectonic earthquakes in the crust. The mine infrastructure provides an opportunity to investigate the effects of fracturing during earthquakes on fault fluid, gas chemistry, and microbiological communities. These promising conditions have led to the building of an earthquake laboratory in the TauTona gold mine in January 2005 as part of the DAFSAM-NELSAM project From the Southern California Earthquake Center: Northridge earthquake had a hypocentral depth of 18 kilometers (11 miles), deep for a California earthquake, but considered shallow compared to other regions. ( In California even the earthquakes are shallow. )
An interesting map is at http://seismo.berkeley.edu/istat/ex_depth_plot/
Actually, their drill began melting. Heat is the biggest obstacle to drilling further than 7 or 8 miles into the earth.