Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ESA satellite imagery credited with breakthrough in earthquake research

19.09.2002


California scientists credit synthetic aperture radar imagery from the European Space Agency with making possible new ways to depict earthquake fault zones and uncovering unusual earthquake-related deformations. Their study of imagery from a 1999 earthquake in the western US could provide a new way to identify active faults and help track when the last earthquake occurred on a fault zone.



Writing in last week’s issue of Science magazine, researchers from the Scripps Institution of Oceanography at the University of California in San Diego, and the California Institute of Technology detailed their studies of the so-called “Hector Mine” earthquake, a magnitude 7.1 earthquake that tore through 28 miles of faults in the Mojave Desert. Named after a nearby abandoned mine in the remote area, the earthquake caused virtually no damage. It was, however, the “perfect” event to use satellite and radar technologies to document unique characteristics of faults, said Scripps’ Yuri Fialko, the study’s lead author.
The earthquake was comprehensively imaged with interferometric synthetic aperture radar (InSAR), which uses a series of satellite recordings to detect changes in the Earth’s surface. The most surprising finding that came out of the analysis of the imagery was the first evidence that faults can move backwards.
“Even small stress perturbations from distant earthquakes can cause faults to move a little bit, but it’s only been known to cause this motion in a forward sense,” Fialko said in a Scripps announcement of the study’s publication in Science. “Here we observed the faults coming backwards, due to relatively small stress changes, which is really quite unusual.”


The article argues that the backward motion on the faults is caused by the dissimilar nature of material within the faults, rather than frictional failure. The results, Failko said, will guide new seismic studies to areas with contrasting fault materials and can then be used to identify potentially active faults.

Co-author Peter Shearer of Scripps credited the study’s detailed results to the “breakthrough” offered by InSAR technology.

“Prior to InSAR, all we had were spot measurements of the deformation field,” the Scripps scientist said. “With InSAR we have millions of points and thus a continuous picture of the deformation across southern California.”

Using the satellite data, the study was able to document both vertical and horizontal terrain displacements of several millimetres to several centimetres across kilometre-wide zones centred on faults.

“The findings became possible due to highly successful satellite missions of the European Space Agency,” the scientists were cited as saying by the Scripps announcement.

In the Science article, the authors pointed out that the earthquake area had been imaged repeatedly by ESA’s ERS-1 and ERS-2 satellites over the past 10 years. The research team generated and analysed all possible interferometric pairs that included the earthquake date, ending up with 15 interferograms from a descending orbit, and five interferograms from an ascending orbit.

The first synthetic aperture radar was launched in 1991 as one of three main instruments on ESA’s ERS-1 satellite. It was followed by a second on ERS-2 in 1995. These highly successful ESA satellites have collected a wealth of valuable data on the Earth’s land surfaces, oceans, and polar caps. Today, several hundred research groups worldwide use ERS data to further their studies. With ERS data, the InSAR technique represents a major breakthrough in Earth sciences, allowing scientists to understand better earthquakes and other natural events.

Europe’s latest environmental satellite, Envisat, was launched earlier this year carrying an advanced SAR (ASAR). Envisat’s ASAR instrument is the first permanent spaceborne radar to incorporate dual-polarisation capabilities - the instrument can transmit and receive signals in either horizontal or vertical polarisation. This dramatically improves the capability of SAR to discriminate between different types of terrain compared with the sensors on the earlier ERS generation of satellites, while offering a continuity of service to users working with the InSAR technique.

Henri Laur | alfa
Further information:
http://www.esa.int

More articles from Earth Sciences:

nachricht Upwards with the “bubble shuttle”: How sea floor microbes get involved with methane reduction in the water column
27.05.2020 | Leibniz-Institut für Ostseeforschung Warnemünde

nachricht An international team including scientists from MARUM discovered ongoing and future tropical diversity decline
26.05.2020 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

Black nitrogen: Bayreuth researchers discover new high-pressure material and solve a puzzle of the periodic table

29.05.2020 | Materials Sciences

Argonne researchers create active material out of microscopic spinning particles

29.05.2020 | Materials Sciences

Smart windows that self-illuminate on rainy days

29.05.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>