Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tonga quake not conducive to tsunami

14.03.2007
Seismologists at Washington University in St. Louis and their colleagues in Australia, Japan and Tonga have determined why a large earthquake in Tonga did not cause a large tsunami. A tsunami warning was issued around the Pacific Rim following the magnitude 8.0 earthquake on May 3, 2006, but the resulting tsunami was very minor and caused no damage.

Tsunamis generally result from shallow-thrust earthquakes, which occur when the seafloor is pushed downward beneath the land in places like Japan, Chile, Indonesia and Mexico. The researchers found instead that this earthquake was slab-tearing event — a rupturing of the down-going seafloor beneath Tonga. This explains why the tsunami was smaller than expected, and suggests that large earthquakes in Tonga may typically be of the slab-tearing variety, consistent with the lack of large historical tsunamis in Tonga.

Douglas A. Wiens, Ph.D., Washington University professor of earth and planetary sciences in Arts & Sciences, and his collaborators quickly assembled their equipment and deployed seven stations to record the aftershocks some 60 kilometers beneath the surface. Washington University technical scientist Patrick Shore and graduate student David Heeszel, along with Australian and Tongan co-workers, installed the seismographs. Shore and Heeszel sailed on a small ship for several days to deploy the seismographs on a group of islands near Ha'apai, Tonga.

"A shallow-thrust earthquake's main shock would have been shallower than what we found," Wiens said. "Because that part of the world does not want a repeat of the Sumatra experience, we wanted to determine the nature of the earthquake. Our Washington University group has done extensive analyses of Tongan earthquakes, so other researchers and the National Science Foundation got in touch quickly and we had equipment installed in early June."

"The Sumatra earthquake surprised a lot of people, and the size of the Tongan one also surprised us, so we wanted to make sure there was not a tsunami hazard in the region. If all the large earthquakes are of the slab-tearing variety like the May 2006 event, it doesn't appear that there is one."

Heeszel and Wiens presented their results at the Winter Meeting of the American Geophysical Union, held Dec. 10-15, 2006 in San Francisco. The research is sponsored by the National Science Foundation.

Tony Fitzpatrick | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Earth Sciences:

nachricht Massive impact crater from a kilometer-wide iron meteorite discovered in Greenland
15.11.2018 | Faculty of Science - University of Copenhagen

nachricht The unintended consequences of dams and reservoirs
14.11.2018 | Uppsala University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>