Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Great earthquakes, water under pressure, high risk

28.03.2014

Interdisciplinary research reveals interactions between plate tectonics, fluids and quakes

The largest earthquakes occur where oceanic plates move beneath continents. Obviously, water trapped in the boundary between both plates has a dominant influence on the earthquake rupture process.


GPS measurements of the displacement vectors (Image: GFZ)


Mechanism of an Earthquake (Image: Manuela Dziggel, GFZ)

Analyzing the great Chile earthquake of February, 27th, 2010, a group of scientists from the GFZ German Research Centre for Geosciences and from Liverpool University found that the water pressure in the pores of the rocks making up the plate boundary zone takes the key role (Nature Geoscience, 28.03.2014).

The stress build-up before an earthquake and the magnitude of subsequent seismic energy release are substantially controlled by the mechanical coupling between both plates.

Studies of recent great earthquakes have revealed that the lateral extent of the rupture and magnitude of these events are fundamentally controlled by the stress build-up along the subduction plate interface.

Stress build-up and its lateral distribution in turn are dependent on the distribution and pressure of fluids along the plate interface.

“We combined observations of several geoscience disciplines - geodesy, seismology, petrology. In addition, we have a unique opportunity in Chile that our natural observatory there provides us with long time series of data,” says Onno Oncken, director of the GFZ-Department “Geodynamics and Geomaterials”.

Earth observation (Geodesy) using GPS technology and radar interferometry today allows a detailed mapping of mechanical coupling at the plate boundary from the Earth’s surface. A complementary image of the rock properties at depth is provided by seismology. Earthquake data yield a high resolution three-dimensional image of seismic wave speeds and their variations in the plate interface region.

Data on fluid pressure and rock properties, on the other hand, are available from laboratory measurements. All these data had been acquired shortly before the great Chile earthquake of February 2010 struck with a magnitude of 8.8.

“For the first time, our results allow us to map the spatial distribution of the fluid pressure with unprecedented resolution showing how they control mechanical locking and subsequent seismic energy release”, explains Professor Oncken. “Zones of changed seismic wave speeds reflect zones of reduced mechanical coupling between plates”.

This state supports creep along the plate interface. In turn, high mechanical locking is promoted in lower pore fluid pressure domains. It is these locked domains that subsequently ruptured during the Chile earthquake releasing most seismic energy causing destruction at the Earth’s surface and tsunami waves.

The authors suggest the spatial pore fluid pressure variations to be related to oceanic water accumulated in an altered oceanic fracture zone within the Pacific oceanic plate. Upon subduction of the latter beneath South America the fluid volumes are released and trapped along the overlying plate interface, leading to increasing pore fluid pressures.

This study provides a powerful tool to monitor the physical state of a plate interface and to forecast its seismic potential. 

Marcos Moreno et al.: “Subduction locking and fluid pressure distribution correlate before the 2010 Chile earthquake”, Nature Geoscience, Vol. 7(2014), Issue 4, pp. 292-296, DOI: 10.1038/NGEO2102, 28.03.2014 

Franz Ossing
Helmholtz Centre Potsdam
GFZ German Research Centre for Geosciences
Deutsches GeoForschungsZentrum
- Head, Public Relations -
Telegrafenberg
14473 Potsdam / Germany
e-mail: ossing@gfz-potsdam.de
Tel. +49 (0)331-288 1040
Fax +49 (0)331-288 1044
http://www.gfz-potsdam.de/

Franz Ossing | GFZ Potsdam

More articles from Interdisciplinary Research:

nachricht When the Brain Grows, the IQ Rises
16.02.2016 | Technische Universität Chemnitz

nachricht Standard BMI inadequate for tracking obesity during leukemia therapy
29.01.2016 | Children's Hospital Los Angeles

All articles from Interdisciplinary Research >>>

The most recent press releases about innovation >>>

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

Im Focus: Worldwide Success of Tyrolean Wastewater Treatment Technology

A biological and energy-efficient process, developed and patented by the University of Innsbruck, converts nitrogen compounds in wastewater treatment facilities into harmless atmospheric nitrogen gas. This innovative technology is now being refined and marketed jointly with the United States’ DC Water and Sewer Authority (DC Water). The largest DEMON®-system in a wastewater treatment plant is currently being built in Washington, DC.

The DEMON®-system was developed and patented by the University of Innsbruck 11 years ago. Today this successful technology has been implemented in about 70...

Im Focus: Computational high-throughput screening finds hard magnets containing less rare earth elements

Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.

The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...

Im Focus: Atomic precision: technologies for the next-but-one generation of microchips

In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.

In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...

Im Focus: Researchers demonstrate size quantization of Dirac fermions in graphene

Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices

Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.

Im Focus: Graphene: A quantum of current

When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene

In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

Challenges of rural labor markets

20.05.2016 | Event News

International expert meeting “Health Business Connect” in France

19.05.2016 | Event News

 
Latest News

3-D model reveals how invisible waves move materials within aquatic ecosystems

30.05.2016 | Materials Sciences

Spin glass physics with trapped ions

30.05.2016 | Materials Sciences

Optatec 2016: Robust glass optical elements for LED lighting

30.05.2016 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>