A new discovery helps us to understand the complex nature of earthquakes

July 08, 2005

This release is also available in Spanish

Álvaro Corral, a physicist at the Universitat Autònoma de Barcelona, has discovered that the structure of the recurrence time of earthquakes, which is the time interval between successive earthquakes, is similar to the spatial structure of physics systems when they change phase in the "critical points". The research has been and shows that the time interval between successive earthquakes depends on the time that elapsed between previous earthquakes. Although this is dependent upon statistics, the discovery may help to improve risk estimation.

Examples of critical phenomena in nature include when water changes state, moving from liquid to gaseous form, and when a magnet is at the critical point, where it loses its magnetism because of the high temperature. In the second example the magnet has a property that exists only at the moment when it changes state. This property is called self-similarity at different scales. When the temperature is below the critical point, the microscopic magnets that form the magnetic fields are well ordered and point mainly all in the same direction. When the temperature rises above the critical point, everything becomes chaotic, each microscopic magnet points in a random direction, and there is no global magnetic field. When the temperature is at the critical point, on the borderline, the microscopic magnets that point in the same direction are grouped together in small clusters. If we step back and look at a larger area, we see that these clusters are grouped also in clusters of clusters, and the same thing occurs each time we look at a larger area. This is what is meant by self-similarity at different scales.

The discovery made by the UAB researcher is that this self-similarity at different scales also occurs in the time intervals between earthquakes. This means that if we note the different earthquakes that have taken place in a given zone over a large period of time, we see that they are grouped together, but the most surprising thing is that if we look at a longer period of time, the groups of earthquakes are themselves also grouped in larger clusters. And the same happens for any period of time, for earthquakes of any magnitude, wherever they take place in the world. This has a fundamental implication on the type of phenomenon that earthquakes are. Rather than being chaotic, as one might think, we can consider them to be critical.

As Corral confirmed, "for this self-similar structure to exist, the role of correlations between earthquakes must be very important, that is, the interval between earthquakes must be dependant on previous earthquakes in a very determined way." Dr. Corral clarified by saying "This does not mean that this dependence is determinist; it does not allow us to predict when the next earthquake will occur, but there is a clear statistical dependence that may help to improve risk estimation."
-end-
Álvaro Corral. (photographs by Jordi Pareto)

http://www.uab.es/uabdivulga/img/alvaro1.JPG

http://www.uab.es/uabdivulga/img/alvaro2.JPG

http://www.uab.es/uabdivulga/img/alvaro3.JPG

Universitat Autonoma de Barcelona

Related Earthquakes Articles from Brightsurf:

AI detects hidden earthquakes
Tiny movements in Earth's outermost layer may provide a Rosetta Stone for deciphering the physics and warning signs of big quakes.

Undersea earthquakes shake up climate science
Sound generated by seismic events on the seabed can be used to determine the temperature of Earth's warming oceans.

New discovery could highlight areas where earthquakes are less likely to occur
Scientists from Cardiff University have discovered specific conditions that occur along the ocean floor where two tectonic plates are more likely to slowly creep past one another as opposed to drastically slipping and creating catastrophic earthquakes.

Does accelerated subduction precede great earthquakes?
A strange reversal of ground motion preceded two of the largest earthquakes in history.

Scientists get first look at cause of 'slow motion' earthquakes
An international team of scientists has for the first time identified the conditions deep below the Earth's surface that lead to the triggering of so-called 'slow motion' earthquakes.

Separations between earthquakes reveal clear patterns
So far, few studies have explored how the similarity between inter-earthquake times and distances is related to their separation from initial events.

How earthquakes deform gravity
Researchers at the German Research Centre for Geosciences GFZ in Potsdam have developed an algorithm that for the first time can describe a gravitational signal caused by earthquakes with high accuracy.

Bridge protection in catastrophic earthquakes
Bridges are the most vulnerable parts of a transport network when earthquakes occur, obstructing emergency response, search and rescue missions and aid delivery, increasing potential fatalities.

Earthquakes, chickens, and bugs, oh my!
Computer scientists at the University of California, Riverside have developed two algorithms that will improve earthquake monitoring and help farmers protect their crops from dangerous insects, or monitor the health of chickens and other animals.

Can a UNICORN outrun earthquakes?
A University of Tokyo Team transformed its UNICORN computing code into an AI-like algorithm to more quickly simulate tectonic plate deformation due to a phenomenon called a ''fault slip,'' a sudden shift that occurs at the plate boundary.

Read More: Earthquakes News and Earthquakes Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.