Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Minerals are key to earthquakes deep in the Earth


A team of geologists can tell you more about earthquakes in "Middle Earth" than can the whole trilogy of "The Lord of the Rings."

Specifically, how do earthquakes happen in Earth’s tightly squeezed middle layers where pressure is far too great to allow any shifting of the rock? According to a paper published in the April 1 issue of the journal Nature, breakdown of the mineral serpentine provides enough wiggle room to trigger an earthquake. The report suggests a new mechanism to explain how quakes can occur at such depths.

"This exciting work addresses the central question of how large earthquakes can be generated in deep subduction zones," said Robin Reichlin, program director in the National Science Foundation (NSF) division of earth sciences, which funded the research. "This has been a much-debated topic, and this work goes a long way toward showing that dehydration of minerals plays an important role in this process."

Haemyeong Jung, Harry W. Green II and Larissa Dobrzhinetskaya of the University of California at Riverside, point out that while it is impossible to break anything by normal brittle fracture at pressures higher than those found at only a few 10s of kilometers (km) deep, earthquakes occur continuously at depths close to 700 km.

What is the explanation of this paradox?

A mechanism called "dehydration embrittlement" breaks down the mineral serpentine, to form the mineral olivine, accompanied by the release of water. That water can assist brittle failure at high pressure, but how? Green explains that before now, scientists have expected faulting instability only if the volume change during serpentine breakdown is positive.

In their article, the team reports experiments conducted between 10,000 and 60,000 times the pressure of the atmosphere at sea level, corresponding to depths in the earth of 30-190 km. Over that pressure range, the volume upon dehydration of serpentine changes from strongly positive to markedly negative, yet the faulting instability remains.

The microstructures preserved in the rocks after faulting provide insight into why this is so. The results confirm that earthquakes can be triggered by serpentine breakdown down to depths of as much as 250 km.

"I am becoming more and more convinced that mineral reactions also are involved in triggering shallow earthquakes such as those that threaten California," Green said. "Our hope is that we learn more about the thing we know least about, the initiation part of these earthquakes, how they get started. This is what we are trying to understand."

Additional Contacts:
NSF Program Contact: Robin Reichlin,, 703-292-8550
UC-RiversideContact: Kris Lovekin,, 909-787-2495

NSF is an independent federal agency that supports fundamental research and education across all fields of science and engineering, with an annual budget of nearly $5.58 billion. NSF funds reach all 50 states through grants to nearly 2,000 universities and institutions. Each year, NSF receives about 40,000 competitive requests for funding, and makes about 11,000 new funding awards. NSF also awards over $200 million in professional and service contracts yearly.

Receive official NSF news electronically through the e-mail delivery system, NSFnews. To subscribe, send an e-mail message to In the body of the message, type "subscribe nsfnews" and then type your name. (Ex.: "subscribe nsfnews John Smith")

Cheryl Dybas | NSF
Further information:

More articles from Earth Sciences:

nachricht UCI and NASA document accelerated glacier melting in West Antarctica
26.10.2016 | University of California - Irvine

nachricht Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union

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 light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

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...

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

Prototype device for measuring graphene-based electromagnetic radiation created

28.10.2016 | Power and Electrical Engineering

Gamma ray camera offers new view on ultra-high energy electrons in plasma

28.10.2016 | Physics and Astronomy

When fat cells change their colour

28.10.2016 | Life Sciences

More VideoLinks >>>