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 Climate change weakens Walker circulation
20.10.2017 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen

nachricht Shallow soils promote savannas in South America
20.10.2017 | Senckenberg Forschungsinstitut und Naturmuseen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

Metallic nanoparticles will help to determine the percentage of volatile compounds

20.10.2017 | Materials Sciences

Shallow soils promote savannas in South America

20.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>