Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The area of influence of earthquakes could be larger than is currently thought

22.11.2006
Dr Álvaro Corral, a Ramón y Cajal researcher for the UAB Department of Physics, studies the relationships between the time and place of earthquake occurrences (ie, the jumps between an initial earthquake and another earthquake at a later time in another place) using statistical physics methods.

By analysing data on the distance between consecutive earthquakes, Dr Corral has concluded that the area of influence of seismic activity could be larger than was thought until now. The result of his work has been published in Physical Review Letters.

According to Corral, this work could lead to support for the idea of long-range earthquake triggering. It has always been thought that the influence of an earthquake was restricted to the rupture zone created by the earthquake at a geological fault, but the researchers now suspect that an earthquake may produce "aftershocks" much further afield, even on the opposite side of a tectonic plate to a main shock.

The diffusion of earthquake occurrences could be like a drop of ink in water. When the ink drop is added (the type of problem usually studied in statistical physics), an ink molecule collides with the water molecules at certain moments and in certain positions; similarly, a series of earthquakes are said to appear in time and in space. However, the reality is that the characteristics of these two cases are very different.

The expansion of the ink molecules occurs on a characteristic scale: that of the ink molecules colliding with water molecules (ie, they always collide after moving a relatively set distance in a relatively set amount of time). Yet earthquakes do not spread in such a normal, regular way. The distance between one earthquake and the subsequent earthquake can be larger or smaller than in previous cases, and the variation seems to be completely arbitrary. There is no characteristic scale.

The data observed seem to imply that the boundary for the influence of earthquakes could be much further away from the epicentre than was previously thought. It is difficult to calculate this boundary, since beyond a distance of 200 kilometres, the influence of an earthquake is hard to distinguish from "background seismicity", that is, the occurrence of other, unrelated earthquakes. Dr Corral believes that more sophisticated analysis techniques could be used to overcome this problem.

Scale models

The researcher has also observed that the earthquake occurrences in a certain region, such as California, could be extrapolated to the whole planet. In other words, the spatiotemporal occurrence of earthquakes in California is a scale model of what happens in the whole world. By observing this region, therefore, we are seeing a smaller version of the whole world. This shows the strange, fractal nature of seismicity, that is, that it maintains its form irrespective of its scale.

The results of this research also show that the diffusion of earthquakes does not depend on their size: small and large earthquakes spread in the same way. Therefore, small earthquakes, which are much more frequent, are the best model to use for the occurrence of larger earthquakes. This magnitude independence is anti-intuitive, and the researcher cannot yet offer any explanation for the phenomenon.

Octavi López Coronado | alfa
Further information:
http://www.uab.es

More articles from Earth Sciences:

nachricht NASA looks to solar eclipse to help understand Earth's energy system
21.07.2017 | NASA/Goddard Space Flight Center

nachricht Scientists shed light on carbon's descent into the deep Earth
19.07.2017 | European Synchrotron Radiation Facility

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>