Featured Research

from universities, journals, and other organizations

2006 Tectonic Plate Motion Reversal Near Acapulco Puzzles Earthquake Scientists

Date:
August 6, 2007
Source:
University of Colorado at Boulder
Summary:
A reversal of tectonic plate motion between Acapulco and Mexico City in the last half of 2006 probably didn't ease seismic strain in the region or the specter of a major earthquake anticipated there in the coming decades, says a University of Colorado at Boulder professor.

A reversal of tectonic plate motion near Acapulco, Mexico, in 2006 (colored arrows) as measured by GPS satellites did little to ease seismic strain in the region and the potential for a large earthquake that could impact Mexico City 175 miles away, according to a new study led by CU-Boulder.
Credit: CU-Boulder

A reversal of tectonic plate motion between Acapulco and Mexico City in the last half of 2006 probably didn't ease seismic strain in the region or the specter of a major earthquake anticipated there in the coming decades, says a University of Colorado at Boulder professor.

Instead of creeping toward Mexico City at about one inch per year - the expected speed from plate tectonic theory - the region near Acapulco moved in the opposite direction for six months and sped up by four times, said CU-Boulder aerospace engineering Professor Kristine Larson.

The changes in motion were detected by analyzing data from GPS satellite receivers set up in Guerrero, Mexico, that were installed by the National Autonomous University of Mexico (UNAM) under the direction of UNAM geophysicist Vladimir Kostoglodov and augmented by CU-Boulder.

"The million-dollar question is whether the event makes a major earthquake in the region less likely or more likely," said Larson, whose research is funded in part by the National Science Foundation. "So far, it does not appear to be reducing the earthquake hazard."

A paper on the subject by Larson, the University of Tokyo's Shin'ichi Miyazaki and UNAM's Kostoglodov and José Antonio Santiago was published Aug. 1 in Geophysical Research Letters.

Scientists use GPS satellite receivers to record laser pulses from spacecraft to measure tiny movements in Earth's crust.

The question of earthquake hazard is particularly important for Guerrero, since it is located 175 miles southwest of Mexico City, Larson said. "A very large earthquake in Guerrero would produce seismic waves that would travel quickly to the Mexican capital, and since Mexico City is built on water-saturated lakebed deposits that amplify seismic energy, the results would be catastrophic," she said.

In 1985, a magnitude 8.1 earthquake triggered by the Cocos Plate dipping under the North American Plate off the west coast of southern Mexico struck along the coast north of Guerrero and killed 10,000 people in Mexico City, injured about 50,000 and caused an estimated $5 billion in property damage.

Since the last major earthquake in northwest Guerrero was a 7.6 magnitude event in 1911, many scientists think the area is ripe for a much larger earthquake, likely in the range of 8.1 to 8.4, Larson said. Geophysicists refer to the impending earthquake as the "Guerrero Gap," she said.

"Before GPS we thought the ground moved at a constant speed between earthquakes," Larson said. "The recognition of these transient events where the plate reverses direction is arguably the most important geophysical discovery that has stemmed from the introduction of GPS measurements."

The Guerrero slip events recorded by Larson and Kostoglodov's research team in 2006 are the largest ever reported in the world.

Studies of the Guerrero Gap are helping scientists better understand other subduction zones around the world, including the Cascadia region off the coast of Washington and Oregon, Larson said. Smaller but much faster backwards slip events have occurred there, as have very large earthquakes in previous centuries.


Story Source:

The above story is based on materials provided by University of Colorado at Boulder. Note: Materials may be edited for content and length.


Cite This Page:

University of Colorado at Boulder. "2006 Tectonic Plate Motion Reversal Near Acapulco Puzzles Earthquake Scientists." ScienceDaily. ScienceDaily, 6 August 2007. <www.sciencedaily.com/releases/2007/08/070802130847.htm>.
University of Colorado at Boulder. (2007, August 6). 2006 Tectonic Plate Motion Reversal Near Acapulco Puzzles Earthquake Scientists. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2007/08/070802130847.htm
University of Colorado at Boulder. "2006 Tectonic Plate Motion Reversal Near Acapulco Puzzles Earthquake Scientists." ScienceDaily. www.sciencedaily.com/releases/2007/08/070802130847.htm (accessed August 20, 2014).

Share This




More Earth & Climate News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

AFP (Aug. 19, 2014) — A solar cell that resembles a flower is offering a new take on green energy in Japan, where one scientist is searching for renewables that look good. Duration: 01:29 Video provided by AFP
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) — Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
Wildfire Hits California's Angeles National Forest

Wildfire Hits California's Angeles National Forest

Reuters - US Online Video (Aug. 17, 2014) — A wildfire sweeps across the Angeles National Forest prompting campers to quickly leave as officials began evacuating the area -- local media. Gavino Garay reports. Video provided by Reuters
Powered by NewsLook.com
Symphony Performs at Southern Utah's Red Rocks

Symphony Performs at Southern Utah's Red Rocks

AP (Aug. 16, 2014) — The Utah Symphony hopes to complement the beauty of Utah's soaring red rocks and canyons with free desert performances near Utah's national parks this weekend. (Aug. 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins