It's About Liberty: A Conservative Forum
Topics => Science, Technology, & Medicine => Topic started by: rickl on April 16, 2011, 12:21:33 AM
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Swarm of Quakes have Experts Concerned
Page Last Updated: Friday April 15, 2011 10:09am PDT
Nevada Seismologists are keeping a close eye on an area southwest of Hawthorne, Nevada where hundreds of earthquakes have been detected since Sunday.
" It's a little bit concerning in a sense.. The largest earthquakes in these sequences are pretty large in size." Graham Kent is Director of Nevada Seismological Laboratory at the University of Nevada Reno. He says there have been hundreds of earthquakes southwest of Hawthorne over the past few days. The largest-- recorded at a 4.4 in size.
"These are the biggest in a sequence we've seen at least in the last couple of years." Kent says unlike the 2008 quakes in Somersett that damaged so many homes, these earthquakes are fortunately not underneath a community.
Size is not the only reason Kent says they are watching the swarm of quakes closely. The location of these quakes is on top of a fault that has until now remained unknown or has not been active. Kent then made an eerie comparison, "Whats really interesting about most of these earthquakes we've experienced. Short of the Chilean and Japanese; Haiti, Baha, even Christchurch.. Were on unknown faults.
But Kent says just because those devastating quakes happened on un-named faults does not mean that the series of quakes near Hawthorne will lead to a big quake there. Reno, Carson City and the Las Vegas valley all lie on top of fault lines. And right now, there is no way to predict where the next big quake will occur.
"That's yet another reason why you don't want to look at the map and go phew, I'm safe. We're in earthquake country and so we have to be prepared.
Link (http://www.mynews4.com/story.php?id=41029&n=122)
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Is that near the salt repositories where we wanted to store the nuke waste?
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For some reason I thought we knew where all the fault lines were.
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For some reason I thought we knew where all the fault lines were.
Not at all. There are faults that haven't gone off in centuries if not millennia, and will surprise us one day. I don't think that any place on Earth is immune to earthquakes. Some places are more susceptible than others, of course.
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Even Minnesota has fault lines and a history of seismic activity (http://www.morris.umn.edu/earthquakes/epicenters2.html), and we are far, far away from what anyone would consider "earthquake territory".
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Even Minnesota has fault lines and a history of seismic activity (http://www.morris.umn.edu/earthquakes/epicenters2.html), and we are far, far away from what anyone would consider "earthquake territory".
Huh. I remember some science prof telling me eons ago that MN's hot spot was SW and that nothing got over 4.0! I guess he was full of it! The center mass of the state with the west central area being prominent seem to get the most activity. But for larger potential magnitudes I believe the St.Louis area (New Madrid fault) is the nearest us.
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...for larger potential magnitudes I believe the St.Louis area (New Madrid fault) is the nearest us.
That's always been my understanding a well.
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Charleston, SC had a pretty nice one in the 1800s (http://en.wikipedia.org/wiki/Charleston_earthquake). That's pretty out of the way from what you think of as typical earthquake territory too.
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Hey, 7.3, pretty impressive.
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Even Minnesota has fault lines and a history of seismic activity (http://www.morris.umn.edu/earthquakes/epicenters2.html), and we are far, far away from what anyone would consider "earthquake territory".
Interesting that we were just discussing this a couple weeks ago...
Magnitude 2.5 Earthquake Strikes Near Alexandria, Minn. (http://www.myfoxtwincities.com/dpp/news/minnesota/alexandria-mn-earthquake-apr-29-2011)
ALEXANDRIA, Minn. - A rare earthquake struck western Minnesota early Friday, rattling ceiling tiles and prompting a few curious callers to phone 911 but going largely unnoticed by most of the sleeping public, authorities said.
The quake, which the U.S. Geological Survey said was magnitude-2.5, struck at 2:20 a.m. and was felt mostly in the Alexandria area.
Sgt. Tom Egan of the Douglas County sheriff's office said staff at the county's 911 center felt it and took 25 to 30 calls from the public, mostly from people who were just curious. By contrast, he said, county dispatchers typically get hundreds of calls during severe thunderstorms.
Callers reported some noise and minor movement, including "ceiling tiles bouncing just a touch," Egan said. But he said nobody reported any damage or anyone hurt. Relatively few people in the largely rural area would have been awake at the time, he said.
He said the department was referring callers to the USGS web site for further information.
Minnesota gets a "feelable" earthquake every five to 10 years on average, though that can vary a lot -- and more often than not, they're in west-central Minnesota, said Val Chandler, a geophysicist with the Minnesota Geological Survey.
The last one confirmed felt was in 1994 in Granite Falls, he said. Chandler said one official in Alexandria who felt this quake told him it felt like a bulldozer going by his house for about 15 seconds.
The USGS said the largest earthquake recorded in Minnesota was a magnitude 4.6 quake that caused minor damage to walls and foundations in Stevens County around Morris. But Chandler said the most destructive was in Staples in 1917. Its magnitude was estimated at 4.3, and it knocked over chimneys, shook items off shelves and shattered windows, he said.
"You can have an earthquake just about anywhere but you only have big earthquakes on faults that are active," said Gary Patterson, a geologist at the Center for Earthquake Research and Information at the University of Memphis.
The Alexandria area is not on an active fault, Chandler said.
The prevailing theory on such midcontinent earthquakes is that they're linked to stresses in the large North American plate that might occasionally jostle ancient faults into weak activity.
The USGS put the epicenter about three miles west of Alexandria but qualified that with a large, seven-mile degree of uncertainty.
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As long as the Kensington Runestone is still intact!
;D