Slashdot Mirror
"Slow" Earthquakes May Help Predict Major Quakes
Iphtashu Fitz writes "Think all earthquakes last only seconds or minutes? Think again! Scientists at the University of Washington are measuring a "slow" earthquake some 12 to 25 miles underground that could last as long as a month. Along with the UW scientists, seismologists at the Geological Survey of Canada and Central Washington University have documented at least nine previous so-called slow earthquakes going back to 1992. They seem to occur every 14 months or so, the last one occuring in February and March of last year. These earthquakes, also known as slow-slip earthqakes, can release as much energy as a magnitude 6.8 earthquake but because it's released over such a long period of time nobody on the surface even notices it. One key question the scientists are trying to answer is whether these slow earthquakes add to or relieve stress in the tectonic plates, which could ultimately help to predict major earthqakes."
Another way to put is like this: Imagine a build-up of gas in a stomach. Perhaps a slow release of the gas into the intestinal tract occurs. This does release some energy, but now the stresses in the intestines are increased. Then comes the big fart, and relief ensues. Ahhhh!
Or imagine a river with two reservoirs. The upper one releases energy slowly, filling the lower reservoir, which fills, then reaches bursting point. The energy release at one place does reduce the overall energy potential of the whole system, but increases the local energy of the lower reservoir.
This same effect can occur with ANY quake or energy release, which can lower the overall energy level of the system, but may locally increase stresses somewhere else.
Fear! Uncertainty! Doubt! Speculation! Oh My! The world is comming to an end! Maybe we should have a Giant Space Laser that reduces stress in the earth's plates! When will the world end? Today? Tommorow? Yesterday, and this is just the afterlife? ...time for more coffee. Is this a slow news day, or what?
...to hear whether piezoelectricity can be used to detect quakes as well. With all of the smashing and crashing going on, one would think it would have the potential to generate radio waves such that a properly tuned instrument could receive|detect the signal.
:-)
It usually isn't too difficult to detect earthquakes. Trying to stand up and failing is a perfectly good indicator that (a reasonably large) one is going on
Plus there's seismographs and whatnot that are really pretty good now.
The much more interesting problem is how to predict earthquakes. For this, piezoelectric mechanisms offer no advantage over "conventional" methods.
Sailing over the event horizon
...say to the other stress fracture during an earthquake?
"Hey, it's not my fault!"
... but this whole Teutonic Plate Movement thing sounds kinda scary and images of blonde hair and blue eyes spring to mind.
Free Firefox news reader.
Why don't they just call their local psychic. There are even 1-800 numbers for that.
Evolution or ID?