Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


UC Riverside geophysicist says triggered deep earthquakes provide insight into how such earthquakes get started


Harry Green comments on a paper in Nature

Harry Green, Distinguished Professor of Geology and Geophysics in the Institute of Geophysics and Planetary Physics and the department of earth sciences at UC Riverside

In a commentary in the Aug. 21 issue of Nature, Harry Green, Distinguished Professor of Geology and Geophysics in the Institute of Geophysics and Planetary Physics and the department of earth sciences at UC Riverside, explains that two large, deep earthquakes (depth > 300 km below the surface of the earth) that occurred in Aug. 2002 in the Tonga subduction zone were causally related.

The Tonga subduction zone is approximately beneath the Fiji Islands in the Pacific Ocean. The two earthquakes were 300 km apart from each other and the difference in their depth was 65 km. Their magnitudes were 7.6 and 7.7.

In the commentary, Green sheds light on a paper by Tibi et al. also appearing in the Aug. 21 issue of Nature. Tibi et al. argue that the second large earthquake was triggered by the passage of seismic waves generated by the first earthquake.

“Tibi and colleagues’ observations are a major advance in understanding deep earthquakes,” Green said. “They might provide a new constraint on the mechanism by which these earthquakes begin. Their work provides a major piece of information as to how earthquakes get started, which may in the long run contribute to the prediction of damaging earthquakes that threaten people in California and elsewhere.”

The authors demonstrated for the first time remote triggering of one deep earthquake by another. “The Tonga earthquakes occurred only 7 minutes apart,” said Green. “Equally interesting, the triggered earthquake occurred in a place where no earthquakes have ever been recorded before.”

Green explained that the observations by Tibi et al. have significant implications for the physical process that initiates deep earthquakes. In the commentary, he outlines the three principal physical mechanisms that have been proposed by geophysicists to explain the initiation of deep earthquakes. “One of these observations can be ruled out by Tibi et al.’s observations,” said Green. “Moreover, we can use the recent seismological work of other researchers to show that one of the remaining two mechanisms is the most probable cause.” That mechanism is ‘phase-transformation-induced faulting,’ which Green and a graduate student discovered in 1989.

The UC Riverside Department of Earth Sciences offers the B.S. degree in geology and geophysics. These programs are designed for students with a strong interest in various aspects of the Earth sciences. The department offers the M.S. and Ph.D. in geological science. The department offers, too, a program built around the core research areas of organic and paleoenvironmental evolution, earthquake science and geodynamics, and quantitative Earth surface processes.

Iqbal Pittalwala | UC Riverside
Further information:

More articles from Earth Sciences:

nachricht Receding glaciers in Bolivia leave communities at risk
20.10.2016 | European Geosciences Union

nachricht UM researchers study vast carbon residue of ocean life
19.10.2016 | University of Miami Rosenstiel School of Marine & Atmospheric Science

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>