Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NASA satellite helps scientists see effects of earthquakes in remote areas

06.02.2003


The unique capabilities of a NASA earth-observing satellite have allowed researchers to view the effects of a major earthquake that occurred in 2001 in Northern India near the border of Pakistan.



Lead author Bernard Pinty of the Institute for Environment and Sustainability in the Joint Research Centre of the European Commission, Ispra, Italy, and colleagues from the U.S., France and Germany, used the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA’s Terra satellite to observe the effects of a massive earthquake in the Gujarat province of India.

Considered one of the two most damaging seismic events in Indian recorded history, the Gujarat earthquake struck with a magnitude of 7.7 (Richter scale) on January 26, 2001. About 20,000 people died and another 16 million people were affected. Local residents reported fountains of water and sediments spouting from the Earth following the earthquake.


As a result of the earthquake’s intense ground shaking, loosely-packed, water-saturated sediments in the area liquefied, behaving more like a liquid than a solid. Ground water flowed up to the surface carrying sediments, flooding large areas including ancient riverbeds.

"Although the instrument’s multiangle and multispectral capabilities weren’t specifically developed for the purpose of detecting surface water, this is an exciting application that merits further investigation," said co-author David J. Diner, MISR Principal Investigator at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. "Of significance to the Gujarat event is MISR’s acquisition of compelling evidence of surface water far from the earthquake’s epicenter, particularly over remote locations inaccessible to teams on the ground."

Aside from collecting scientific data in hard to reach places, MISR also provides a map overview of what happened and the area affected. Such information could be used to detect places where survey teams could concentrate their efforts. In this case, MISR data demonstrated that specific areas of the Rann were more affected than others by dewatering. In addition, the data were instrumental in identifying distant sites of liquefaction. Such information may help to validate earthquake models and to further constrain relationships between earthquake magnitudes and distances of impacts.

"Satellites provide the best way to have a global view of an entire region, hundreds of square kilometers can be observed in a few minutes, and this happens at any time they fly over a place," said Pinty. "In the case of Gujarat, scientists were able to conduct surveys near the epicenter but could hardly access other regions also affected by the earthquake, partly because of the proximity of Pakistani border, a high security and politically sensitive region."

The earthquake’s epicenter was located about 80 kilometers (50 miles) east of the city of Bhuj, but the MISR instrument found dewatering, or release of water and sediment due to compression and liquefaction, as far as 200 km (124 miles) from the epicenter. Additionally, there was significant dewatering all along an 80-100 kms (50-62 miles) wide (south to north) ancient salt lake bed to the north of Bhuj, known as the Rann of Kutch.

In the days to weeks following the earthquake, along with ground cracks and other types of deformation, water flowed to the surface and progressively evaporated in various places. A year later, scientists could still observe the consequences of the earthquake across the Rann because the water that came up to the surface was very salty. After evaporation, the salt was left on the ground and MISR was able to detect it also.

The MISR instrument views the sunlit face of the Earth simultaneously at nine widely spaced angles, and provides ongoing global coverage with high spatial detail. Its imagery is carefully calibrated to provide accurate measurements of the brightness, contrast, and color of reflected sunlight.

One way MISR registers surface features is by picking up different wavelengths of light as they are reflected off the Earth’s surface. As the satellite passes overhead, MISR collects information over a 400 km (248 mile) swath at a spatial resolution of 275 meters (300 yards), instantaneously assessing surface features over large regions. Since the bright soils of the Rann of Kutch reflect most of the Sun’s incoming near-infrared radiation, and water bodies absorb near-infrared radiation, MISR can detect the contrast and thereby tell where dewatering from the earthquake occurred. Changes in reflection at different view angles also proved advantageous to identify the presence of surface water in other regions.


###
A paper on the study appears in the current issue of the American Geophysical Union’s journal, EOS.

Krishna Ramanujan | EurekAlert!
Further information:
http://www.gsfc.nasa.gov/topstory/2003/0115gujarat.html
http://www.gsfc.nasa.gov/

More articles from Earth Sciences:

nachricht More than 100 years of flooding and erosion in 1 event
28.03.2017 | Geological Society of America

nachricht Satellites reveal bird habitat loss in California
28.03.2017 | Duke 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: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>