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 NASA eyes Pineapple Express soaking California
24.02.2017 | NASA/Goddard Space Flight Center

nachricht 'Quartz' crystals at the Earth's core power its magnetic field
23.02.2017 | Tokyo Institute of Technology

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>