Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New System Can Warn of Tsunamis Within Minutes

07.03.2011
Seismologists have developed a new system that could be used to warn future populations of an impending tsunami only minutes after the initial earthquake.

The system, known as RTerg, could help reduce the death toll by giving local residents valuable time to move to safer ground. The study by researchers at the Georgia Institute of Technology appears in the March 5 edition of Geophysical Research Letters.

“We developed a system that, in real time, successfully identified the magnitude 7.8 2010 Sumatran earthquake as a rare and destructive tsunami earthquake. Using this system, we could in the future warn local populations, thus minimizing the death toll from tsunamis,” said Andrew Newman, assistant professor in the School of Earth and Atmospheric Sciences.

Typically, a large subduction zone earthquake ruptures at a rate near 3 kilometers/second and anywhere from 20 kilometers to 50 kilometers below the earth’s surface. Because of the depth, vertical deformation of the crust is horizontally smoothed, causing the size of uplift to remain rather small. When these earthquakes occur in the ocean, the resulting waves may only measure about 20 centimeters high for a magnitude 7.8 event.

Tsunami earthquakes, however, are a rare class of earthquakes that rupture more slowly, at 1-1.5 kilometers /second and propagate up to the sea floor, near the trench. This makes the vertical uplift much larger, resulting in nearby wave heights up to 10- 20 meters in nearby coastal environments. Such is the case of the Sumatran earthquake with reported wave heights of up to 17 meters, causing a death toll of approximately 430 people.

“Because tsunami earthquakes rupture in a shallow environment, we can't simply use a measurement of magnitude to determine which ones will create large waves,” said Newman. “When they occur, people often don't feel that they're significant, if they even feel them in the first place, because they seem like they're an order of magnitude smaller than they actually are.”

Tsunami earthquakes typically rupture more slowly, last longer and are less efficient at radiating energy, so when RTerg uses its algorithmic tools to find a quake matching these attributes, it sends an alert to the National Oceanic and Atmospheric Administration's Pacific Tsunami Warning Center as well as the United States Geological Survey's National Earthquake Information Center.

Here's how it works. Usually within four minutes, RTerg gets a notification from one of the tsunami warning centers that an earthquake has occurred. This notice gives the system the quake's location, depth and approximate magnitude. If the earthquake is determined to be of magnitude 6.5 or higher, it takes about a minute to request and receive data from around 150 seismic stations around the world. Once it collects this data, it uses its algorithm to run through every second of the rupture and determine the incremental growth of energy and ascertain whether the quake was a tsunami earthquake.

Newman and his team have used seismology readings from previous tsunami earthquakes, such as the one in Nicaragua in 1992 and the one that hit Java in 2006, but the Sumatran event was the first tsunami quake that occurred when RTerg was online in real time. With that quake, the system identified the event as a potential tsunami earthquake after eight and a half minutes, and sent a notification out shortly thereafter. When applied to a production warning system, the tool will be most valuable, since analysts are available 24/7 to evaluate the algorithm results.

“For most tsunami earthquakes, inundation of the coastal environment doesn't occur until about 30-40 minutes after the quake. So we'll have about 20-30 minutes to get our information to an automatic warning system, or to the authorities,” said Newman. “This gives us a tangible amount of time to get people out of the way.”

Currently, Newman and his team are working to test and implement a technique for RTerg that could shave another minute or more from the warning time. In addition, they are planning to rewrite the algorithm so that it can be used at all U.S. and international warning centers.

David Terraso | Newswise Science News
Further information:
http://www.gatech.edu

More articles from Earth Sciences:

nachricht Volcanoes and glaciers combine as powerful methane producers
20.11.2018 | Lancaster University

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

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First diode for magnetic fields

Innsbruck quantum physicists have constructed a diode for magnetic fields and then tested it in the laboratory. The device, developed by the research groups led by the theorist Oriol Romero-Isart and the experimental physicist Gerhard Kirchmair, could open up a number of new applications.

Electric diodes are essential electronic components that conduct electricity in one direction but prevent conduction in the opposite one. They are found at the...

Im Focus: Nonstop Tranport of Cargo in Nanomachines

Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.

Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | 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

 
Latest News

Removing toxic mercury from contaminated water

21.11.2018 | Life Sciences

New China and US studies back use of pulse oximeters for assessing blood pressure

21.11.2018 | Medical Engineering

Exoplanet stepping stones

21.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>