Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Special issue of BSSA focuses on 2004 Sumatra earthquake

11.01.2007
The great Sumatra-Andaman earthquake of 2004 is the best recorded large earthquake in history and has revealed the extent of study still necessary to understand such devastating events. New data overturn the commonly held view that great earthquakes only occur in fast, young subduction zones.

The 2004 earthquake is the focus of the January special issue of the Bulletin of the Seismological Society of America (BSSA), in which scientists present research and analyses about the current state of earthquakes and tsunamis, as learned from the Sumatra--Andaman event.

"The 2004 earthquake necessitates a revisitation of commonly accepted views on the relationship between the size of great earthquakes and physical characteristics of subduction zones," write guest editors Susan L Bilek, Ph.D., of New Mexico Tech; Kenji Satake, Ph.D., of Active Fault Research Center in Japan; and Kerry Sieh, Ph.D., of California Institute of Technology.

A great earthquake is defined as having a moment magnitude greater than 9.0. The moment magnitude scale refers to the physical size of fault rupture and the movement across the fault, thereby measuring the strength of the earthquake. Prior to the 2004 earthquake, scientists assumed that great earthquakes only occurred at the site of a young subduction zone, where one tectonic plate is pushed quickly underneath another one. Scientists are rethinking their theories, based on data collected after the earthquake.

The 2004 Sumatra-Andaman earthquake is the best recorded seismic event in history. With a Moment magnitude of 9.1 - 9.3, it ranks as the third largest earthquake in recorded history and the first to supply sufficient data to allow for a detailed analysis of what exactly occurred at the source of rupture. This issue's articles by Rhie et al., and Chlieh et al., combine several different datasets to present a more complete picture of the fault rupture.

In order to evaluate the 2004 great earthquake, scientists took advantage of new technology, such as GPS, satellite telemetry, field tests, and unique datasets developed to understand this giant earthquake and subsequent tsunami. Both the duration of the earthquake, nearly 600 seconds, and the length of the rupture, between 1250 km and 1600 km, exceeded any previously recorded. Limited historical data had suggested that such a powerful earthquake was not possible at this site.

"Because of the long duration and size of the earthquake, scientists have developed new techniques to analyze earthquakes such as these," explains Bilek. "Many of these new techniques incorporate a range of the new technologies, thus giving a better picture of what happened on the fault."

The special issue features research on the key aspects of the great earthquake. Highlights include an article by authors Stein and Okal, who suggest that the correlation between great earthquakes and fast, young subduction zones disappears when a longer time frame is considered. The short earthquake history sampled doesn't address the rarity of earthquakes with a magnitude >9.0, making it difficult to assess risk of great earthquakes in subduction zones elsewhere.

Scientists seek to understand this great earthquake and tsunami in order to better prepare for similar events. Authors Rajendran et al., suggest that a similar event in the exact location is unlikely. Results from preliminary study of the Andaman Islands and the coast of India suggest that great earthquakes and resulting tsunami are quite rare. Based on the evaluation of sand layers mixed with archeological ruins on the Indian coast, authors suggest that the previous great earthquake and tsunami would likely have occurred 1000 years ago.

The guest editors write of the potential new understanding that will result from focusing on the 2004 earthquake: "Hopefully, the legacy of the science presented in this volume will be a greater understanding of earthquake and tsunami processes that will be useful in advancing the resilience of our communities to Nature's violence."

Nan Broadbent | EurekAlert!
Further information:
http://www.msn.com

More articles from Earth Sciences:

nachricht NASA examines newly formed Tropical Depression 3W in 3-D
26.04.2017 | NASA/Goddard Space Flight Center

nachricht Early organic carbon got deep burial in mantle
25.04.2017 | Rice 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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>