Posted on 04/11/2006 9:02:02 PM PDT by NormsRevenge
PORTLAND, Ore. - Using hand-me-down technology from the Cold War, scientists have discovered that the seafloor off the Pacific Northwest is a jumping kind of place, with thousands of small, swarming earthquakes and tectonic plates that are slowly rearranging themselves.
The findings could mean that a "Big One" earthquake may not be as severe as previously thought, the lead researcher said.
An article in the journal Geology by researcher Robert Dziak describes the findings. Dziak is an associate professor at Oregon State University who also works for the National Oceanic Atmospheric Administration. He's stationed at OSU's Hatfield Marine Science Center in Newport.
Dziak's article describes both new data and a record of earthquakes going back more than a decade. Much of the data was collected using once-secret Cold War "hydrophones" the Navy uses to track submarine movements in the Pacific Ocean. Dziak said the Navy provides controls the system of seafloor microphones and relays the data to Newport.
Dziak says the evidence is that multiple tectonic plates off the Pacific Northwest appear to be rearranging themselves.
The plates have been slowly jamming into each other. Dziak said one boundary among them appears to be turning into a fault that's more like the San Andreas Fault to the south in California. Instead of ramming together, the plates are rubbing past each other, he said.
Emphasizing that the conclusions are tentative, Dziak said the consequence could be a shortening of the fault along the Pacific Northwest, so a major earthquake wouldn't be so extensive or severe.
The rearrangement could limit the potential for a magnitude 9 earthquake, he said.
"It would still ruin our day, but it wouldn't be quite so bad," he said.
Dziak also said that the hydrophone project has turned up evidence of intense earthquake activity, intense clusters of quakes that previously had gone undetected. These are associated with underwater volcanic activity and are like the swarms of earthquakes that can precede volcanic eruptions such as that at Mount St. Helens.
The quakes were small, on the order of magnitudes 2-4, but numerous, Dziak said, with as many as a thousand of them in a three-week period.
To cite the ever-relevant Carlos Mencia...
DEET DEE DEE!
LOL... an odd headline.
If they were moving quickly, THAT would be news!
"The plates have been slowly jamming into each other. Dziak said one boundary among them appears to be turning into a fault that's more like the San Andreas Fault to the south in California."
The new fault will be called..."Bush's Fault"
Maybe Seattle does NOT need to rebuild the Viaduct after all?
Thank Heaven!
The actual Seattle Fault which runs under Seattle and Puget Sound is more of a shaking and tsunami threat to Seattle than the Cascadia Megathrust offshore.
These guys don't know cr@p (not that I'm saying I do) but they are not considering thrust faults at all. Sure, they may see one plate rubbing against another with little swarming quakes, but they can't measure the pressure distributed over a wider area, which may result in a Northridge or Kobe styled thrust quake.
I believe you.....that's what the last quake here was like....a lotta banging and shaking!
The last quake there actually was the subduction zone, but it's very deep when it's right under Seattle.
The Seattle Fault is right at the surface. An earthquake on it of equal magnitude to the 2001 Nisqually earthquake would make the Nisqually quake look like a joke.
http://seattletimes.nwsource.com/html/localnews/2002185299_earthquake20m.html
Scary.....another reason we stay 25 plus miles away from Seattle/Bellevue.....and another reason we keep lots of goodies on hand for disasters.....I remember the quake of 1965 also, and was at the beach when the Alaska quake hit (couldn't understand why the parents greeting us were so frantic when we returned).....we didn't know anything about it, and left the beach(luckily) before the tsunami hit.
good point,, what is being recorded now is a self-buffering or load levelling scenario that eventually will lead up to or give way to major ruptures that are inevitable over larger scales of time.
Yeah, it will be "rebuilt" for them.
What did Mark Twain say? So much return of conjecture from so little investment in fact. Or something like that.
Isn't that what Tectonic Plates is supposed to do, move slowly?
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