MadSci Network: Earth Sciences |
Earthquakes are generated in response to the state of stress the rocks are submited to. They are usual in special regions, that we call plate boundaries, and not so usual in other places, although they can occur in any place given the appropriate conditions. There is no evidence that the number of earthquakes is increasing. What we can notice is that the instruments that can detect earthquakes are now more disseminated in the planet, and great amount of information about that is becoming available, what can cause some confusion about the number of earthquakes. As the population grows, there are much more people living in certain regions, and some regions that had little people nowadays are becoming populated, so, an earthquake can cause many damages and death in regions where in the past we had no sensible seismological activity (as noted by people, at least). In fact, there are evidences that, since the early 1900, the number of earthquakes are globally DECREASING, but very slowly, and we don't have still a statistical study that can prove that. Any more info you need to your study, please feel free to contact us. Eder C. Molina Institute of Astronomy and Geophysics University of Sao Paulo BRAZIL eder@iag.usp.br http://www.iag.usp.br/
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