Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New research maps out trajectory of April 2015 earthquake in Nepal

24.07.2015

Data show earthquake’s multi-stage rupture process

New research has accurately mapped out the movement of the devastating 7.8-magnitude Nepal earthquake that killed over 9,000 and injured over 23,000 people. Scientists have determined that the earthquake was a rupture consisting of three different stages. The study could help a rapidly growing region understand its future seismic risks, according to the study’s authors.


Nepal Earthquake Animation

The Himalayan region is particularly prone to earthquakes and this study will serve as an important benchmark for understanding where future earthquakes may occur, especially since the area has experienced high population growth over the past few decades, the study’s authors said.

The study assessed the presence of low frequency and high frequency waves over the three stages of the earthquake. High frequency waves cause more shaking, thereby posing the greatest risks for structural damages. Low frequency waves are less violent and less damaging to buildings and infrastructure.

“The Nepal earthquake is a warning sign that the region is of high seismic risk, and each earthquake behaves differently. Some earthquakes jump from one fault line to another, whereas the Nepal quake apparently occurred on the same fault line in three different stages, moving eastward,” said Peter Shearer, a geophysicist at Scripps Institution of Oceanography at UC San Diego in La Jolla, California, and a co-author of the new study. “Using this research, we can better understand and identify areas of high seismic hazard in the region.”

This first peer-reviewed study on the April 2015 earthquake in Nepal, “Detailed rupture imaging of the 25 April 2015 Nepal earthquake using teleseismic P waves” was published online July 16 in the American Geophysical Union (AGU) journal Geophysical Research Letters.

Using the Global Seismic Network (GSN), Shearer and Scripps graduate student Wenyuan Fan were able to unravel the complex evolution of fault slips during this earthquake. The study concludes that the rupture traveled mostly eastward and occurred in three distinct stages; Stage 1 was weak and slow; Stage 2 was near Kathmandu and had the greatest slip but was relatively deficient in high-frequency radiation; and Stage 3 was relatively slow as well. Overall, this earthquake was more complicated, with multi-stage movements on multiple faults, than smooth models of continuous rupture on a single fault plane.

“Using the GSN instead of regional array data really enhanced the spatial resolution of the back-projection images and helped us see that frequency-dependent rupture was one of the main features of this earthquake,” said Fan. “Stage 2 was high-frequency-deficient and occurred closest to Kathmandu, which was probably why ground shaking was less severe than expected for such a high-magnitude earthquake.”

The Global Seismic Network provides high-quality broadband digital seismic data for monitoring earthquakes and learning about Earth’s structure. Fan and Shearer used the GSN data because they are open-source, have good coverage of the Nepal region, and have a long history of reliable recordings.

“In general, understanding large earthquakes will inform our ability to forecast the nature of future earthquakes,” said Shearer.

Shearer and Fan hope to use the same methodology to study other large, global earthquakes from the past decade to provide a broader picture of earthquake behavior and help in predicting ground shaking for future events.

The study was funded by the National Science Foundation.

The American Geophysical Union is dedicated to advancing the Earth and space sciences for the benefit of humanity through its scholarly publications, conferences, and outreach programs. AGU is a not-for-profit, professional, scientific organization representing more than 60,000 members in 139 countries. Join the conversation on Facebook, Twitter, YouTube, and our other social media channels.

Notes for Journalists
Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of the article by clicking on this link: http://onlinelibrary.wiley.com/doi/10.1002/2015GL064587/full?campaign=wlytk-41855.5282060185

Or, you may order a copy of the final paper by emailing your request to Nanci Bompey at nbompey@agu.org. Please provide your name, the name of your publication, and your phone number.

Neither the papers nor this press release is under embargo.
Title
“Detailed rupture imaging of the 25 April 2015 Nepal earthquake using teleseismic P waves”

Authors:
W. Fan and P. M. Shearer: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA.

Contact Information for the Authors:
Wenyuan Fan: w3fan@ucsd.edu

Peter Shearer: +1 (858) 534-2260, pshearer@ucsd.edu


AGU Contact:
Nanci Bompey
+1 (202) 777-7524
nbompey@agu.org

Scripps Contact:
Christina Wu
+1 (858) 534-3654
chw261@ucsd.edu

Nanci Bompey | American Geophysical Union
Further information:
http://news.agu.org/press-release/new-research-maps-out-trajectory-of-april-2015-earthquake-in-nepal/

More articles from Earth Sciences:

nachricht By saving cost and energy, the lighting revolution may increase light pollution
23.11.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

nachricht Frictional Heat Powers Hydrothermal Activity on Enceladus
23.11.2017 | Universität Heidelberg

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Desert ants cannot be fooled

23.11.2017 | Life Sciences

By saving cost and energy, the lighting revolution may increase light pollution

23.11.2017 | Earth Sciences

Retreating permafrost coasts threaten the fragile Arctic environment

23.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>