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.
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
In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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