In Český Krumlov at night there was an earthquake


12.01.12.Okolo morning in Cesky Krumlov has short tremors. Propulsion reached 2.4 on the Richter scale.

For the Czech countryside is pretty strong aftershocks. All the more so in this region are not typical even small earthquake. Scientists assert that the static homes are not affected.

Tremors in Krumlov accompanied strong sound, which is why some people call the police.


Sound during earthquakes.

Each is accompanied by a strong earthquake sound effect. Eyewitnesses describe the sound in different ways. He likened it thunder, the thunder of the train, the whistle of the wind, the howling of an artillery shell, the explosion, the gurgling. Sound is heard most strongly in the mines, in the caves, at the wells near major cracking. This is, apparently, due to a much more rapid spread of sound in rocks compared to air. So first is usually perceived underground sound wave, and then air. In some cases, especially in the mountains and cities, it is difficult to distinguish a remote underground rumble of thunder surface caused by a collapse of rock masses or buildings.

Sound and shock spread at different rates and often do not coincide in time of exposure. Sound can outperform a concussion, but it can also keep up with him. At the epicenter of the sound is ahead of most jarring, and away from him late. This indicates that the propagation in rock sound waves lose speed faster than seismic. About the nature of sound sources consensus does not exist, and the phenomenon of underground buzz in earthquakes so far been studied very bad. They should be given more attention, as most of the acoustic waves can be one source of the seismic waves and serve as a valuable material for understanding the mechanism of earthquakes.

April 26, 1966 a strong tectonic earthquake in Tashkent. In the center of the city was destroyed by a large number of houses, mostly of the old type, factories, hospitals, schools, a number of public buildings and public institutions. First impulse, accompanied by underground rumble and light flashes occurred in 5 hours 22 minutes in the morning. Intense vibrations lasted for about 6-7 seconds. They were so strong that it was difficult to stay on his feet. The magnitude of the main shock was 51/in, and the amount of released energy reached 10e'5 ergs. In the central part of Tashkent intensity tremors reached 8 points. Main shock followed by aftershocks that occurred within two years. By the end of December 1969 the total number exceeded 1100, the most powerful of them (up 7 points) were recorded on 9 and 24 May, 5 and June 29, July 4, 1966 and March 24, 1967

Pleistoseist area of this earthquake was very small (about 10 km2), Captures only the central part of the city. The earthquake was located directly under the center of the city at a depth of 8 km. The earthquake was associated with shearing along the fault north-west strike. Fault, apparently, is an upthrust — shift the elevated north-eastern wing, the vertical component of the displacement of more horizontal. The north-east wing fracture at the Tashkent earthquake, apparently, was deformed stronger southwest. This is indicated by association with him almost all the aftershock hypocenters (99%), and "bloating" the earth's surface with an amplitude of up to 3.5 cm, re-installed leveling. Study of the effects and the possible mechanism of the Tashkent earthquake allowed geologists and seismologists to conclude that the energy, depth, and dynamic parameters of earthquake April 26, 1966 is the usual and ordinary earthquake Pritashkentskogo seismic area in which possible earthquakes up to 8 points and above.

Source:  Geology

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