The nature is not always favorable to people. Some natural phenomena bear so destructive character that lead to death of millions of people. The most frequent natural disasters are earthquakes, floods, eruptions of volcanoes and a tsunami.
The natural phenomena capable to do essential harm to people are called natural disasters. They have extreme character, are life-threatening and can lead to violation of work of systems of providing. Some natural disasters arise independently (earthquakes, the fires), and some are a consequence of other natural disasters (a tsunami from explosion of a volcano, a flood because of a tropical storm, etc.).
Earthquakes
The earthquake represents a series of the tremors caused by earth movement. Earthquakes result from soil shift. Depending on force of pushes, the earthquake can cause as small damage, and to lead to destruction of the whole cities. The largest in the history of an earthquake occurred in the Indian Ocean in 2004, in Japan in 2011 and in China in 2008. The earthquake in the Indian Ocean had magnitude more than 9 points and led to formation of tsunami which claimed the lives of 229 thousand people. To it on power the earthquake in Japan was close. More than 13 thousand people died from it, even more than 12 thousand were missing. An earthquake in the Chinese province of Sichuan more than 61 thousand people claimed the lives.
Eruptions of volcanoes
The volcanic eruption is followed by emission of huge hot fragments and the heated ashes and also outpouring of a lava. The most dangerous eruptions happen vzryvoobrazno. Most strongly the cities located in close proximity to a volcano suffer from eruptions. So, in the 79th year of our era the ancient Roman city of Pompeii died from eruption of Vesuvius - completely filled up it with ashes. Volcanic ash bears also other danger - rising in the atmosphere, it is capable to spread to long distances and to lead to global climate changes.
Floods
As a result of floods the water level in the rivers and lakes increases that leads to an area zataplivaniye. Floods result from long and plentiful rains, sharp thawing of snow, a tsunami, etc. In 1938 in China there was a flood which nicknamed "Great". Huang He waters spread to such an extent that flooded the huge territory. This flood claimed the lives of millions of people. In 1998 in the same China there was one more big flood which left homeless 14,000,000 people.
Tsunami
The tsunami represents a powerful wave which arises because of the movement of an ocean floor or explosion of a volcano. In 2011 the tsunami 40 meters high fell upon Japan after an earthquake measuring 9 points.