2.5 Mile Deep Hole Drilled Into San Andreas Fault 204
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."
Only 2.5 miles? (Score:4, Insightful)
Re:Only 2.5 miles? (Score:5, Insightful)
It does seem to be less than the record [findarticles.com] there. But we can hardly fualt (har har) the team for not digging the full 50 miles to the asthenosphere. :)
talc as a lubricant (Score:5, Insightful)
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 [wikipedia.org] (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.
Re:The fools! (Score:2, Insightful)
You don't have to look at it like that though- even though the usa contributed to this sad reality it had been stirring since the dawn of time. We as a nation may have done more to push its spread but the truth is it would have happened even if the north american continent never existed.
What it boils down to is people. Not people from this country, people from that country, people with this color skin, people with this color hair, people with this taste in fashion or music, people with this political stance-- none of that matters. People, simply people, are the problem.
Does that mean everyone should die? I used to think so. The truth is though, believe it or not, there are decent people out there that understand what really matters and I believe it is for these peoples sake that everything hasn't completely collapsed yet. These are the people most often ridiculed without cause, leaned on and despised without cause. I would know. I did it to many of them myself.
Re:talc as a lubricant (Score:3, Insightful)
It's called the Hayward fault, and it experiences plenty of creep all along the East Bay. The last quake greater than 4 that happened on it was basically across the street from my apartment. Trust, it's moving, and generally nonviolently (though noticeably at times). In fact, it runs through the middle of Memorial Stadium [wikipedia.org] in Berkeley, which is built in two halves that have crept about a foot and a half offset since the stadium's construction.
Re:Lex Luthor is Pleased (Score:3, Insightful)