Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New technique uses seismic ’garbage’ to view Earth’s interior

11.03.2005


Frees seismologists from ’tyranny’ of waiting for earthquakes



Seismologists have long relied on earthquakes or expensive tools like explosives to help create images of Earth’s interior, but a new method created by University of Colorado at Boulder (CU-Boulder) researchers will produce quicker, cheaper and clearer images.
Rather than waiting for earthquakes, the researchers have recovered surface-wave information from normal seismic noise that is constantly produced by fluctuations in the Earth’s atmosphere and oceans. Measuring surface waves is important because the information helps scientists get a clearer picture of the Earth’s interior, according to Michael Ritzwoller, director of CU-Boulder’s Center for Imaging the Earth’s Interior.

The method is described in the March 11 issue of the journal Science.



"This new technique will give us a better fundamental understanding of the planet by providing much better resolution of Earth’s interior," Ritzwoller said. "It also will diminish what is known in seismology as the ’tyranny of earthquakes,’ which means having to wait for an earthquake to happen to do our jobs."

The new method promises significant improvements in the resolution and accuracy of crust and upper mantle images down to 60 miles or more within the Earth, particularly when used with seismic projects like USArray, according to Nikolai Shapiro, a research associate in the Center for Imaging the Earth’s Interior and the study’s chief author.

Coupled with existing and emerging technology, such as USArray, the new measuring technique will lead to a better fundamental understanding of the structure of the planet and may help save lives in the process, Ritzwoller said. A component of the National Science Foundation’s (NSF) EarthScope program, USArray includes hundreds of portable seismometers that in coming years will be moved over the entire country, producing images of the Earth’s interior to aid in earthquake risk assessment.

"The authors’ application of what used to be ’seismic noise’ to the detailed mapping of the crust and upper mantle will have significant impact on earth science and on seismic hazard mitigation," says James Whitcomb, head of NSF’s deep earth processes section, which funded the research. "This innovative research foretells what’s to come from EarthScope."

Researchers have for years been constructing tomographic images of Earth’s crust and upper mantle from waves generated by earthquakes. That method, known as seismic tomography, reconstructs Earth’s inner structure on a computer screen, slice by slice. The new technique is similar, but is based on organizing ambient seismic noise, which is typically discarded as seismic "garbage."

Seismic tomography is like doing a medical CT scan of the Earth, Ritzwoller said. But when people have a CT scan, doctors are in control and can make images at will. Seismologists can’t control when an earthquake happens, so they can either wait for another one or set off explosives to create their own image-generating waves.

"To move beyond these limitations requires observational methods based on seismic sources other than earthquakes, which is what our method offers," said Shapiro.

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov

More articles from Earth Sciences:

nachricht GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center

nachricht Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>