bd40bc7c7a Asteroseismology (quakes on stars) Helioseismology (quakes on the Sun) Lists of earthquakes Seismite Seismotectonics Submarine earthquake Types of earthquake Quakes on other planets and stars . 1. 157 (6): 911895. January 29, 2009. United States Geological Survey. Adobe PDF (.pdf) format files are provided.
A small subset of earthquake ruptures appear to have propagated at speeds greater than the S-wave velocity. It is principally due to the transfer of the seismic motion from hard deep soils to soft superficial soils and to effects of seismic energy focalization owing to typical geometrical setting of the deposits. In Greek mythology, Poseidon was the cause and god of earthquakes. Fires of the 1906 San Francisco earthquake . The velocity of rupture propagation is orders of magnitude faster than the displacement velocity across the fault. The shallower an earthquake, the more damage to structures it causes, all else being equal.. About 100,000 of these can be felt. Minor earthquakes occur nearly constantly around the world in places like California and Alaska in the U.S., as well as in El Salvador, Mexico, Guatemala, Chile, Peru, Indonesia, Iran, Pakistan, the Azores in Portugal, Turkey, New Zealand, Greece, Italy, India, Nepal and Japan, but earthquakes can occur almost anywhere, including Downstate New York, England, and Australia. Larger earthquakes occur less frequently, the relationship being exponential; for example, roughly ten times as many earthquakes larger than magnitude 4 occur in a particular time period than earthquakes larger than magnitude 5. In the (low seismicity) United Kingdom, for example, it has been calculated that the average recurrences are: an earthquake of 3.74.6 every year, an earthquake of 4.75.5 every 10years, and an earthquake of 5.6 or larger every 100years. This is an example of the GutenbergRichter law. Strike-slip faults tend to be oriented near vertically, resulting in an approximate width of 10km within the brittle crust, thus earthquakes with magnitudes much larger than 8 are not possible. For instance, an earthquake of magnitude 6.0 releases approximately 30 times more energy than a 5.0 magnitude earthquake and a 7.0 magnitude earthquake releases 900 times (30 30) more energy than a 5.0 magnitude of earthquake. Emergency management strategies can be employed by a government or organization to mitigate risks and prepare for consequences.