Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




SHAKE AND BLOW
Slippery clay intensified Japan 2011 tsunami-quake: scientists
by Staff Writers
Tokyo (AFP) Dec 06, 2013


A thin layer of very fine clay with a consistency similar to some cosmetics made Japan's tsunami-causing earthquake of 2011 much more dramatic because it acted as a lubricant, scientists say.

The narrow strip of slippery, wet clay that sits between two tectonic plates off the country's northeast coast allowed them to shift past each other at tremendous speed and to travel much further than in most regular quakes, researchers said.

The finding sheds more light on a catastrophe that claimed more than 18,000 lives when a 9.0 magnitude undersea quake unleashed a towering tsunami that slammed into the coast, destroying whole communities and causing nuclear meltdowns at Fukushima.

Researchers say the stratum, made mostly of material as fine and moist as cosmetic foundation, is very thin, about one to five metres (about 3 to 16 feet), compared with the 40-or so metres found at other major seismically-active plate borders.

"The layer is 90 percent made of low friction clay, called smectite -- material similar to foundation, which tends to become runny and slippery," said Kotaro Ujiie, an associate professor at Tsukuba University.

Ujiie is part of the Japan Trench Fast Drilling Project, which was launched in the immediate aftermath of the 2011 quake, using a deep-sea drilling vessel that allows scientists to bore far under the sea bed.

Researchers used the drill to get samples from the point where the two plates meet, and to measure heat caused by friction after the quake.

They discovered that in areas where the layer of clay is sandwiched between strata of impermeable rock, it becomes even more slippery because of the pressure it is under.

Ujiie said the smectite was formed over a very long period of time from volcanic ash and was originally on the surface, before it slid underneath the other plate.

"This layer of smectite existed in the area before the sinking of the plate started," Ujiie said. "The geological conditions were already there before the quake."

Seismologists are now drilling deep beneath the seabed off the Kii peninsula, southwestern Japan, into a fracture in the Earth's crust known as the Nankai Trough.

Experts have warned the trough, which marks the place where the Philippine Sea plate slides under the Eurasian plate, is the likely source of a monster earthquake sometime in the near future.

Japan's government last year unveiled a worst-case scenario, warning a big quake in the area could kill more than 320,000 people, dwarfing the toll from the 2011 quake-tsunami disaster.

Ujiie and other researchers have found that the tectonic fault in the Nankai Trough is less slippery than that further north.

"Under the Nankai Trough, a relatively new plate is sliding, where there was not enough time to collect and form a smectite layer," Ujiie said.

"But that doesn't mean we can sit back and let our guard down."

The 56,752-ton Chikyu -- "Earth" in Japanese -- was built in 2005 at a cost of $500 million. It is equipped with a 121-metre drill tower that can descend 7,000 metres below the seabed, nearly three times as deep as its predecessors.

It uses GPS with pinpoint accuracy that allow researchers to target very specific areas of the Earth's crust.

Seismically-active Japan experiences 20 percent of the world's major earthquakes every year.

Building standards are high and Japanese people are well-practised at taking cover when quakes strike, meaning damage and death tolls are often much lower than in other parts of the world.

The research, part of a project run by Japan Agency for Marine-Earth Science and Technology (JAMSTEC), was to be published in the Friday edition of the US magazine Science.

.


Related Links
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
Philippine typhoon survivors flee false tsunami alert
Manila (AFP) Dec 01, 2013
About a thousand traumatised survivors of the Philippines' deadliest typhoon fled their homes in one central province following false rumours of a tsunami, civil defence officials said Sunday. Officials in the province of Antique were visiting upland villages where people had fled overnight to convince them there was no danger and it was safe to return to their coastal homes, said Broderick ... read more


SHAKE AND BLOW
China's most moon-like place

LADEE Instruments Healthy and Ready for Science

China launches first moon rover mission

Japanese firm describes proposed 'power belt' for the moon

SHAKE AND BLOW
MAVEN Performs First Trajectory Correction Maneuver

Opportunity Rover Robotic Arm Within Reach of Rock Outcrop

ExoMars program marks critical milestone for ESA and Russia

Deep Space Perils For Indian Spacecraft

SHAKE AND BLOW
300 million Chinese are potential visitors to France: Ayrault

Mixed reaction as US House passes patent reform

NASA Taps Student Teams to Simulate Human Exploration of Other Worlds

Moon gardens: NASA to sow first seeds of future habitat

SHAKE AND BLOW
Turkey keen on space cooperation with China

China space launch debris wrecks villagers' homes: report

Designer: moon rover uses cutting-edge technology

Commentary: Lunar probe boosts "Chinese dream"

SHAKE AND BLOW
Russian android may take on outer space operations at ISS

Repurposing ISS Trash for Power and Water

Russian spacecraft with advanced navigation system docks with ISS

Space freighter docks at International Space Station

SHAKE AND BLOW
Third time a charm: SpaceX launches commercial satellite

Arianespace's role as a partner for the US satellite industry

SpaceX postpones first satellite launch

Second rocket launch site depends on satellite size, cost-benefit

SHAKE AND BLOW
Astronomers find strange planet orbiting where there shouldn't be one

Hubble Traces Subtle Signals of Water on Hazy Worlds

Astronomers detect water in atmosphere of distant exoplanets

The State of Super Earths

SHAKE AND BLOW
Cloud firm Box raises $100 mn

Laser Communication Mission Targets 2017 Launch

New Effect Couples Electricity and Magnetism in Materials

Satellite Cooling System Breakthrough Developed by Lockheed Martin Space Systems




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