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




SHAKE AND BLOW
Breaking the rules for how tsunamis work
by Staff Writers
Los Angeles CA (SPX) Mar 11, 2013


During an earthquake, sections of the sea floor lift up while others sink. This creates tsunamis that propagate trough-first in one direction and crest-first in the other.

The earthquake zones off of certain coasts-like those of Japan and Java-make them especially vulnerable to tsunamis, according to a new study. They can produce a focusing point that creates massive and devastating tsunamis that break the rules for how scientists used to think tsunamis work.

Until now, it was largely believed that the maximum tsunami height onshore could not exceed the depth of the seafloor. But new research shows that when focusing occurs, that scaling relationship breaks down and flooding can be up to 50 percent deeper with waves that do not lose height as they get closer to shore.

"It is as if one used a giant magnifying lens to focus tsunami energy," said Utku Kanoglu, professor at the Middle East Technical University and senior author of the study. "Our results show that some shorelines with huge earthquake zones just offshore face a double whammy: not only they are exposed to the tsunamis, but under certain conditions, focusing amplifies these tsunamis far more than shoaling and produces devastating effects."

The team observed this effect both in Northern Japan, which was struck by the Tohoku tsunami of 2011, and in Central Java, which was struck by a tsunami in 2006.

"We are still trying to understand the implications," said Costas Synolakis, director of the Tsunami Research Center at the USC Viterbi School of Engineering and a co-author of the study. "But it is clear that our findings will make it easier to identify locales that are tsunami magnets, and thus help save lives in future events."

During an earthquake, sections of the sea floor lift up while others sink. This creates tsunamis that propagate trough-first in one direction and crest-first in the other.

The researchers discovered that on the side of the earthquake zone where the wave propagates trough-first, there is a location where focusing occurs - strengthening it before it hits the coastline with an unusual amount of energy that is not seen by the crest-first wave.

Based on the shape, location, and size of the earthquake zone, that focal point can concentrate the tsunami's power right on to the coastline.

In addition, before this analysis, it was thought that tsunamis usually decrease in height continuously as they move away from where they are created and grow close to shore, just as wind waves do. The study's authors instead suggest that the crest of the tsunami remains fairly intact close to the source.

"While our study does not preclude that other factors may help tsunamis overgrow, we now know when to invoke exotic explanations for unusual devastation: only when the basic classic wave theory we use does not predict focusing, or if the focusing is not high enough to explain observations," said Vasily Titov, a researcher at NOAA's Pacific Marine Environmental Laboratory and study co-author.

The study was published online on Feb. 27 by Proceedings of the Royal Society, Series A. It represents the collected efforts of researchers from METU, NOAA, Akdeniz University, CMLA Ecole Normale Superieure Cachan, University College Dublin, HCMR, and the University of Southern California; representing Turkey, France, Ireland, Greece and the United States.

.


Related Links
University of Southern California
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
Floating tsunami trash to be a decades-long headache
Paris (AFP) March 8, 2013
The tsunami that ravaged northeast Japan in March 2011 created the biggest single dumping of rubbish, sweeping some five million tonnes of shattered buildings, cars, household goods and other rubble into the sea. About three-and-a-half million tonnes, according to official Japanese estimates, sank immediately, leaving some 1.5 million tonnes of plastic, timber, fishing nets, shipping contain ... read more


SHAKE AND BLOW
China to use modified rocket for moon landing mission

Water On The Moon: It's Been There All Along

Building a lunar base with 3D printing

US, Europe team up for moon fly-by

SHAKE AND BLOW
Neptec wins contract to develop cameras for European Space Agency's ExoMars Programme

Mars rover 'sleeping' through solar storm

Curiosity Rover's Recovery on Track

NASA's Curiosity rover to be back online next week

SHAKE AND BLOW
Basketball legend Shaq talks tech at SXSW

UK and Kazakhstan agree collaboration in space

Wyle To Provide NASA Ongoing Support For Human Space Flight

Japan, US hold space cooperation talks

SHAKE AND BLOW
China's fourth space launch center to be in use in two years

China to launch new manned spacecraft

Woman expected again to join next China crew roster

China's space station will be energy-efficient

SHAKE AND BLOW
'Goody Bag' Filled With Sample Processing Supplies Arrives on Station

ESA's Columbus Biolab Facility

SpaceX set for third mission to space station

Record Number of Students Control ISS Camera

SHAKE AND BLOW
Vega launcher integration continues for its April mission

SpaceX's capsule arrives at ISS

Dragon Transporting Two ISS Experiments For AMES

SpaceX Optimistic Despite Dragon Capsule Mishap

SHAKE AND BLOW
The Birth of a Giant Planet?

Scientists spot birth of giant planet

NASA's Kepler Mission Discovers Tiny Planet System

Kepler helps astronomers find tiny exo planet

SHAKE AND BLOW
Activists fault WHO report on Fukushima radiation

SimCity climbing from launch wreckage

INRS overcomes a hurdle in the development of terahertz lasers

SSBV And zero2infinity Team Up For Airdrop Recovery




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