Possible Upcoming Major Earthquake Damage on U.S. Pacific Northwest
Scientists used a supercomputer-driven “virtual earthquake” to explore likely ground shaking in a magnitude 9.0 megathrust earthquake in the Pacific Northwest. Peak ground velocities are displayed in yellow and red. The legend represents speed in meters per second (m/s) with red equaling 2.3 m/s. Although the largest ground motions occur offshore near the fault and decrease eastward, sedimentary basins lying beneath some cities amplify the shaking in Seattle, Tacoma, Olympia, and Vancouver, increasing the risk of damage. (Credit: Kim Olsen, SDSU)
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Since January 26, 1700, when the Juan de Fuca plate moved beneath the ocean in the Pacific Northwest with a magnitude 9 earthquake, it has been reported by “Science Daily” in February 2008 that the region of Vancouver, Seattle, and Portland has been fairly quiet. With the old saying, “no news is good news” not applicable in today’s times , the online magazine also reports that a team of scientific researchers — led by seismologist Kim Olsen of San Diego State University — is saying another serious earthquake is in the making.
According to Kim Olsen and the team, similar earthquakes of the 1700 one occurs every 400 to 500 years , which makes arriving in the very near future. Scientists believe that one with a megathrust event of 8 or a higher magnitude is in the making now because of a supercomputer-powered “virtual earthquake” program that has been processed. The professionals involved in the program, in addition to Kim Olsen and her team, consists of researchers from the San Diego Supercomputer Center at UC San Diego and the U.S. Geological Survey.
Reported in the Journal of Seismology, a rupture has been seriously estimated which will begin in the north, heading south along the 600-mile long Cascadia Subduction Zone, with upheaval movement about 1 ½ feet per second in the Seattle area, with 6-inches per seconds in the Tacoma, Olympia and Vancouver areas, and 3-inches in the Portland, Oregon area. Further simulation testing found that earthquakes found in the southern part of the rupture formed a ground motion that was twice as large in many areas. “We also found that these high ground velocities were accompanied by significant low-frequency shaking, like what you feel in a roller coaster, that lasted as long as five minutes – and that’s a long time,” said Olsen.
Further testing by a more recent study, with leader Chris Goldfinger at Oregon State University, has found an extensive fault which tracks the Pacific coast of North America – from Canada to Northern California – which will to trigger major earthquakes along California’s San Andreas Fault. This evidence was found by core samples taken of marine sediments along the seabed of Northern California, with the participating seismologists finding 15 sediment deposits found only when an underwater landslide occurs from an earthquake. “The faults seem to be communicating with each other,” said study leader Chris Goldfinger of Oregon State University.
NASA’s Goddard Space Flight Center, Greenbelt MD and NASA’s Jet Propulsion Laboratory, Pasadena CA, have said that all earthquakes actually will have some affect on Earth’s rotation, but they are barely noticeable. Yet according to Olsen and Goldfinger, the possible upcoming earthquakes in the Northwest area will be very large.
Regardless what NASA says, that will be noticeable in the rotation. The two NASA organizations have routinely calculated earthquake’s effects on the rotation of the Earth in the gravitation field changes on Earth in addition to the length-of-day.
This entry was posted on Saturday, April 12th, 2008 at 1:18 am and is filed under Space Agency News, Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
