Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




SHAKE AND BLOW
Scientists anticipated size and location of 2012 Costa Rica earthquake
by Staff Writers
Atlanta VA (SPX) Dec 27, 2013


Andrew Newman, an associate professor in the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, performs a GPS survey in Costa Rica's Nicoya Peninsula in 2010. Credit: Lujia Feng.

Scientists using GPS to study changes in the Earth's shape accurately forecasted the size and location of the magnitude 7.6 Nicoya earthquake that occurred in 2012 in Costa Rica.

The Nicoya Peninsula in Costa Rica is one of the few places where land sits atop the portion of a subduction zone where the Earth's greatest earthquakes take place. Costa Rica's location therefore makes it the perfect spot for learning how large earthquakes rupture.

Because earthquakes greater than about magnitude 7.5 have occurred in this region roughly every 50 years, with the previous event striking in 1950, scientists have been preparing for this earthquake through a number of geophysical studies. The most recent study used GPS to map out the area along the fault storing energy for release in a large earthquake.

"This is the first place where we've been able to map out the likely extent of an earthquake rupture along the subduction megathrust beforehand," said Andrew Newman, an associate professor in the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology.

The study was published online Dec. 22, 2013, in the journal Nature Geoscience. The research was supported by the National Science Foundation and was a collaboration of researchers from Georgia Tech, the Costa Rica Volcanological and Seismological Observatory (OVSICORI) at Universidad Nacional, University California, Santa Cruz, and the University of South Florida.

Subduction zones are locations where one tectonic plate is forced under another one. The collision of tectonic plates during this process can unleash devastating earthquakes, and sometimes devastating tsunamis. The magnitude 9.0 earthquake off the coast of Japan in 2011 was due to just such a subduction zone eaerthquake.

The Cascadia subduction zone in the Pacific Northwest is capable of unleashing a similarly sized quake. Damage from the Nicoya earthquake was not as bad as might be expected from a magnitude 7.6 quake.

"Fortunately there was very little damage considering the earthquake's size," said Marino Protti of OVSICORI and the study's lead author.

"The historical pattern of earthquakes not only allowed us to get our instruments ready, it also allowed Costa Ricans to upgrade their buildings to be earthquake safe."

Plate tectonics are the driving force for subduction zones. As tectonic plates converge, strain temporarily accumulates across the plate boundary when portions of the interface between these tectonic plates, called a megathrust, become locked together. The strain can accumulate to dangerous levels before eventually being released as a massive earthquake.

"The Nicoya Peninsula is an ideal natural lab for studying these events, because the coastline geometry uniquely allows us to get our equipment close to the zone of active strain accumulation," said Susan Schwartz, professor of earth sciences at the University of California, Santa Cruz, and a co-author of the study.

Through a series of studies starting in the early 1990s using land-based tools, the researchers mapped regions where tectonic plates were completely locked along the subduction interface. Detailed geophysical observations of the region allowed the researchers to create an image of where the faults had locked.

The researchers published a study a few months before the earthquake, describing the particular locked patch with the clearest potential for the next large earthquake in the region.

The team projected the total amount of energy that could have developed across that region and forecasted that if the locking remained similar since the last major earthquake in 1950, then there is presently enough energy for an earthquake on the order of magnitude 7.8 there.

Because of limits in technology and scientific understanding about processes controlling fault locking and release, scientists cannot say much about precisely where or when earthquakes will occur.

However, earthquakes in Nicoya have occurred about every 50 years, so seismologists had been anticipating another one around 2000, give or take 20 years, Newman said. The earthquake occurred in September of 2012 as a magnitude 7.6 quake.

"It occurred right in the area we determined to be locked and it had almost the size we expected," Newman said.

The researchers hope to apply what they've learned in Costa Rica to other environments. Virtually every damaging subduction zone earthquake occurs far offshore.

"Nicoya is the only place on Earth where we've actually been able to get a very accurate image of the locked patch because it occurs directly under land," Newman said. "If we really want to understand the seismic potential for most of the world, we have to go offshore."

Scientists have been able to reasonably map portions of these locked areas offshore using data on land, but the resolution is poor, particularly in the regions that are most responsible for generating tsunamis, Newman said.

He hopes that his group's work in Nicoya will be a driver for geodetic studies on the seafloor to observe such Earth deformation. These seafloor geodetic studies are rare and expensive today.

"If we want to understand the potential for large earthquakes, then we really need to start doing more seafloor observations," Newman said.

"It's a growing push in our community and this study highlights the type of results that one might be able to obtain for most other dangerous environments, including offshore the Pacific Northwest."

.


Related Links
Georgia Institute of Technology
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





SHAKE AND BLOW
Runaway process drives intermediate-depth earthquakes
Stanford CA (SPX) Dec 16, 2013
Stanford scientists may have solved the mystery of what drives a type of earthquake that occurs deep within the Earth and accounts for one in four quakes worldwide. Known as intermediate-depth earthquakes, these temblors originate farther down inside the Earth than shallow earthquakes, which take place in the uppermost layer of the Earth's surface, called the crust. The kinds of quakes tha ... read more


SHAKE AND BLOW
China's moon rover "sleeps" through lunar night

Will the Moon be carved-up?

NASA Releases New Earthrise Simulation Video

Most Chang'e-3 science tools activated

SHAKE AND BLOW
ISRO end year on high note after Mars mission

Mars rover Curiosity gets software upgrade, improved capabilities

Mars One mission: one way ticket to new life

Mars Express heading towards daring flyby of Phobos

SHAKE AND BLOW
Only lawyers profit as tech giants go to war over patents

Boeing Completes Mission Control Center Interface Test

Working With NASA On The Space Structures Of The Future

Sierra Nevada Completes CCDev2, Begins Dream Chaser Flight Test Program

SHAKE AND BLOW
China launches communications satellite for Bolivia

China's moon rover continues lunar survey after photographing lander

China's Yutu "naps", awakens and explores

Deep space monitoring station abroad imperative

SHAKE AND BLOW
Station's Replacement Pump Successfully Restarted

Spacewalk ends, ISS fix a success

Spacewalk ends, station fix a success

ISS Crew Set for Tuesday Pump Replacement Spacewalk

SHAKE AND BLOW
Boeing, Energia Achieve Mixed Results in Counterclaims

Orbital Launches Completes 40th Consecutive Successful Suborbital Rocket For NASA

NASA Awards Launch Services Contract for InSight Mission

Argentina successfully launches research rocket

SHAKE AND BLOW
Using an Atmosphere to Weigh a Planet

Gaia Mission Could Help Map Exoplanets

First detection of a predicted unseen exoplanet

Astronomers solve temperature mystery of planetary atmospheres

SHAKE AND BLOW
New computer memory can hold data 20 years without power

Scientific data lost at alarming rate

Europe's Gaia telescope detaches from Fregat-MT upper stage

Sailing satellites into safe retirement




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement