Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Large Himalaya earthquakes may occur sooner than expected

09.12.2005


While the rupture zones of recent major earthquakes are immune to similar-sized earthquakes for hundreds of years, they could be vulnerable to even bigger destructive temblors sooner than scientists suspect, according to analysis by University of Colorado seismologist Roger Bilham.



Bilham and his research colleagues explained that the magnitude 9.3 Indian Ocean earthquake of December 2004 showed scientists that a giant earthquake can rupture through a region with a recent history of quakes with magnitudes as large as 7.9 on the Richter Scale.

"Following what we learned in 2004, we believe that regions of the Himalaya that have recently experienced magnitude 7.8 earthquakes - like the Kangra district, a hundred years ago - may not be immune to a future larger earthquake," he said.


Bilham’s research of Himalayan earthquakes in the last 1,000 years is part of findings presented in an invited talk, "Unprecedented massive earthquakes in the Himalaya driven by elastic strain stored within the Tibetan Plateau?" Dec. 7 at the American Geophysical Union’s fall meeting in San Francisco.

Bilham recently returned from Kashmir, where he conducted a series of measurements along with Pakistani scientists to assess subsurface fault slip and damage in that region’s October earthquake.

"The Kashmir event released almost 100 times less energy than the Sumatra-Andaman quake in 2004," he said. "The Kashmir rupture was about 16 times smaller in length and five times smaller in width, yet it flattened whole cities in its path."

The Kashmir earthquake was the deadliest earthquake ever in the Indian subcontinent, mostly because of the poor construction quality in the area, Bilham said. "Most of the buildings that collapsed had been constructed in the past two decades.

"It is distressing to see how little attention has been focused on this earthquake by news media in the United States," he said.

Bilham believes medieval earthquakes beneath the Himalaya may have been larger than any in the past 300 years. Bilham and his colleagues are trying to determine what governs the recurrence interval and the size of these historically much larger earthquakes.

"We postulate that a giant reservoir of elastic energy exists not just in the Himalaya but also beneath southern Tibet," he said. "This reservoir of energy is tapped by Himalayan earthquakes more efficiently if ruptures are geographically long."

Bilham and his colleagues developed a "theoretical law" linking earthquakes of different size to their geographic length and repeat time. They concluded that recent earthquakes require about 500 years to repeat, but the medieval ones require almost 2,000 years.

"We suggest that these rare events must have exploited much longer ruptures than any we have seen recently, like those that slipped in the Kangra and Kashmir earthquakes," he said. "We find also that these rare great events can re-rupture parts of the plate boundary that slip in modest earthquakes up to magnitude 7.6. As a result, recent rupture zones could be vulnerable to greater destruction sooner than one might suspect from India’s rate of approach toward Asia."

The tremendous Indian Ocean earthquake in 2004 gave seismologists an unprecedented look at the mechanics of the world’s largest earthquakes. Using data recorded by digital seismometers all over the world, scientists were able to determine that the rupture propagated 1,000 miles from south to north at 5,000 miles per hour during the first 10 minutes of the earthquake.

Roger Bilham | EurekAlert!
Further information:
http://www.colorado.edu

More articles from Earth Sciences:

nachricht Algorithm provides early warning system for tracking groundwater contamination
14.08.2018 | DOE/Lawrence Berkeley National Laboratory

nachricht Artificial Glaciers in Response to Climate Change?
10.08.2018 | 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: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>