Subscribe free to our newsletters via your
. 24/7 Space News .


Subscribe free to our newsletters via your




















TECTONICS
New study pinpoints stress factor of mega-earthquake off Japan
by Staff Writers
San Diego CA (SPX) Mar 04, 2016


This is a graphic of the gravity data off Japan where the 2011 magnitude 9 earthquake occurred. Image courtesy Scripps Institution of Oceanography, UC San Diego. For a larger version of this image please go here.

Scripps Institution of Oceanography, UC San Diego researchers published new findings on the role geological rock formations offshore of Japan played in producing the massive 2011 Tohoku-oki earthquake, one of only two magnitude 9 mega-earthquakes to occur in the last 50 years. The study, published in the journal Nature, offers new information about the hazard potential of large earthquakes at subduction zones, where tectonic plates converge.

The magnitude 9 quake, which triggered a major tsunami that caused widespread destruction along the coastline of Japan, including the Fukushima nuclear plant disaster, was atypical in that it created an unusually large seismic movement, or slip, of 50 meters (164 feet) within a relatively small rupture area along the earthquake fault.

To better understand what may have caused this large movement, Scripps researchers used gravity and topography data to produce a detailed map of the geological architecture of the seafloor offshore of Japan. The map showed that the median tectonic line, which separates two distinct rock formations, volcanic rocks on one side and metamorphic rocks on the other, extends along the seafloor offshore.

The region over the earthquake-generating portion of the plate boundary off Japan is characterized by variations in water depth and steep topographic gradients of about six kilometers (3.7 miles). These gradients, according to the researchers, can hide smaller variations in the topography and gravity fields that may be associated with geological structure changes of the overriding Japan and subducting Pacific plates.

"The new method we developed has enabled us to consider how changes in the composition of Japan's seafloor crust along the plate-boundary influences the earthquake cycle," said Dan Bassett, a postdoctoral researcher at Scripps and lead author of the study.

The researchers suggest that a large amount of stress built up along the north, volcanic rock side of the median tectonic line resulting in the earthquake's large movement. The plates on the south side of the line do not build up as much stress, and large earthquakes have not occurred there.

"There's a dramatic change in the geology that parallels the earthquake cycle," said Scripps geophysicist David Sandwell, a co-author of the study. "By looking at the structures of overriding plates, we can better understand how big the next one will be."

Yuri Fialko, a professor in the Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics at Scripps and Anthony B. Watts from the University of Oxford are also co-authors on the study.

.


Related Links
University of California - San Diego
Tectonic Science and News






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

Previous Report
TECTONICS
Mariana Trench: 7 miles deep, the ocean is still a noisy place
Newport OR (SPX) Mar 03, 2016
For what may be the first time, scientists have eavesdropped on the deepest part of the world's oceans and instead of finding a sea of silence, they discovered a cacophony of sounds both natural and caused by humans. For three weeks, a titanium-encased hydrophone recorded ambient noise from the ocean floor at a depth of more than 36,000 feet in a trough known as Challenger Deep in the fabl ... read more


TECTONICS
NASA May Return to Moon, But Only After Cutting Off ISS

Lunar love: When science meets artistry

New Lunar Exhibit Features NASA's Lunar Reconnaissance Orbiter Imagery

NASA releases strange 'music' heard by 1969 astronauts

TECTONICS
Revisit NASA's Mars Pathfinder and Rover In 360 Viewer

Opportunity Mars Rover Goes Six-Wheeling up a Ridge

Jarosite in the Noctis Labyrinthus Region of Mars

Trace Gas Orbiter and Schiaparelli are joined

TECTONICS
Tools and Talent at Michoud to Complete SLS Core Stage Welding in 2016

Orion Simulations Help Engineers Evaluate Mission Operations for Crew

Orion Test Hardware in Position for Solar Array Test

NASA Space Program Now Requires Russian Language

TECTONICS
Logistics Rule on Tiangong 2

China to launch second space lab Tiangong-2 in Q3

China's moon lander Chang'e-3 enters 28th lunar day

Staying Alive on Tiangong 2

TECTONICS
Paragon wins NASA ISS water processor development contract

NASA's Science Command Post Supports Scott Kelly's Year In Space

After nearly a year in space, Scott Kelly craves human contact

Scott Kelly returns to earth, but science for NASA's journey to Mars continues

TECTONICS
At last second, SpaceX delays satellite launch again

Arianespace Soyuz to launch 2 Galileo satellites in May

SpaceX postpones rocket launch again

Russian rocket engines ban could leave US space program in limbo

TECTONICS
Imaging Technique May Help Discover Earth-Like Planets Around Other Stars

Newly discovered planet in the Hyades cluster could shed light on planetary evolution

Imaging technique may help discover Earth-like planets

Longest-Lasting Stellar Eclipse Discovered

TECTONICS
Bone research could yield stronger synthetic materials

New catalyst makes hydrogen peroxide accessible to developing world

Research demonstrates that air data can be used to reconstruct radiological releases

California researchers reveal how to hack a 3D printer




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








The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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 All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.