How strong can earthquakes in Germany be? Where in Europa are the earthquake activities concentrated? These questions are the basis for risk assessments and become relevant when it comes to the safety of buildings or the generation of tsunami.
GFZ-EMEC, all earthquakes Mw >3,5
GFZ-EMEC, all earthquakes Mw >6
For the first time, scientists of the GFZ German Research Centre for Geosciences have succeeded in setting up a harmonized catalogue of earthquakes for Europe and the Mediterranean for the last thousand years. This catalogue consists of about 45000 earthquakes, reported in the latest issue of the „Journal of Seismology".
Earthquakes occur with different frequencies of occurrence, meaning that in some regions, strong earthquakes happen with time gaps of hundreds of years. Such rare events can cause a false feeling of security which belies the true risk. This is compounded by the fact that instrumental measurements only go back for roughly a century, and reliable data for smaller quakes for about half that long.
Thus, the only way to assess the actual risk is the analysis of historical earthquake accounts. „The catalogue that we present here covers the earthquakes of the last thousand years with magnitudes of Mw 3,5 and larger in the northern part of our research area and magnitudes Mw4,0 for the southern part", explains Dr. Gottfried Grünthal of the GFZ. „Our earthquake catalogue stretches over an area from the Azores to the Caspian Sea and from the Sahara to the North Cape." Based on some 80 mostly national earthquake catalogues, more than 100 other sources and own analyses of key historical earthquakes, the EMEC-catalogue (European-Mediterranean Earthquake Catalogue) offers the first reliable, regional, long-time database with a harmonized assessment of earthquake magnitudes.
In bringing together all these sources with their considerable differences in magnitude or intensity scales, particular care was taken to harmonize the latter in the form of moment magnitude Mw. The earthquakes in the EMEC are catalogued from 1000 AD bis 2006. In areas south of 40°N and east of 10°E the available data allow for an analysis starting from 300 AD. Of course these data are not complete, especially in the early phase of the catalogued time period.The point in time after which data for certain magnitudes can be assumed as sufficiently complete is very different within the research area. For example, earthquakes with a magnitude of Mw 6,5 and above in the Levant exist more or less completely since 300 AD, and earthquakes of Mw 5 and above since 1965. In Germany, the catalogue of earthquakes with Mw 5 and greater is sufficiently complete since about 1600.
„Part of the EMEC-publication is also a list of so-called fake-quakes, i.e. quakes that have been reported erroneously due to errors of the chroniclers, errors in dates or other mistakes", explains GFZ scientist Gottfried Grünthal. Importance was also attached to a user-friendly web page: „On the GFZ-EMEC-website, data can be downloaded according to the wishes of the users and epicentre maps can be generated, stored and printed in customized scales of time and space and map projections."
The EMEC catalogue provides a reliable basis for the risk assessment of earthquakes and quake generated tsunami. Moreover, it is a solid foundation for a whole range of other geoscientific research as well as a source for investigations outside of science.
Pictures in a printable resolution can be found here:
Source: Grünthal G., Wahlström R. (2012) The European-Mediterranean Earthquake Catalogue (EMEC) for the last millennium. Journal of Seismology 16(3): 535-570, DOI: 10.1007/s10950-012-9302-y
F.Ossing | EurekAlert!
Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter
17.08.2017 | Swansea University
Climate change: In their old age, trees still accumulate large quantities of carbon
17.08.2017 | Universität Hamburg
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Information Technology