Prepare by

Semyonovka 2015  

Molchanova Svetlana
Fedorenko Christina
Form 10
School of Semyonovka

- one of the most terrible and destructive natural phenomena. Annals of the earthquake victims in the millions, hundreds of ruined cities and villages, damaged and destroyed buildings.

Earthquakes occur due to sudden rupture of rocks land and release mechanical energy and are accompanied by tremors, bumps and vibrations of the earth's surface, covering vast areas. During strong earthquakes violated the integrity of the soil, destroyed buildings and structures, bridges, roads, fail communal energy networks occur rock falls, landslides, river and sometimes stems appear lakes.

Earthquake belongs first place causes economic losses and casualties.

Today, science is not yet able to give an accurate prediction of time of occurrence of the earthquake, but it is well known that the main danger to the territory of Moldova are earthquakes that occur at depths of 90 - 150 kilometers in a local region of Vrancea in Romania.
A place where there is an underground hit, called the earthquake source, the point in the depths of the earth, where it starts to break - hypocenter, its projection on the surface of the earth - the epicenter. Seismic waves propagate in the ground at a speed of 6 to 8 kilometers per second. First reaches the earth's surface so-called longitudinal waves. The strongest fluctuations caused by transverse and surface waves that come in a few seconds after the first tangible hesitation. The main parameters that characterize the strength and character of the earthquake, are energy intensity on the surface of the earth, the magnitude and depth of focus. Intensity - a measure of the value of the ground state is determined by the degree of destruction built by people and buildings. Changes in the nature of the earth's surface and data about the feelings experienced by people and is measured in points. In our country to assess the intensity of underground storm a 12-point scale. Brief description of the earthquake:

- earthquake up to 4 points, as a rule, destruction does not, they are felt by the people, for a light rattling and vibrations of objects, dishes, glasses, creaking doors;

- 5 points (quite strong) - the shaking of buildings, fluctuations furniture, cracks in the glass and plaster;

- 6 points (strong) - falling from the walls of paintings, pieces break off plaster, cracked walls, light damage to Adobe-Adobe buildings;

- 7 points (very strong) in the walls of the stone houses cracked, partial destruction of chimneys;

- with 8 points (destructive) - falling cornices, chimneys, through cracks in the walls of houses and buildings collapse, people find it difficult to stay on his feet;

- 9 points (devastating) - severe damage and destruction of stone houses, collapse of walls and ceilings;

- 10 points (destroys) the destruction of the stone houses, the bending of rails, cracks in the soil up to 1 meter wide, landslides, rockslides;

- with 11 points (catastrophe) - the destruction of the stone houses, landslides, large landslides in the mountains, numerous cracks and ditches on the surface,

- with 12 points (severe accident) - no structure can not withstand, huge cracks in the ground, numerous landslides and avalanches, waterfalls, lakes, changing the course of rivers.

During the earthquake very rare cause of human death is the movement of soil by itself.

Дата добавления: 2015-08-18