Volcanoes. Earthquakes. Geysers.

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Volcanoes. Earthquakes. Geysers. : 

Volcanoes. Earthquakes. Geysers. Lecture No. 11

What is a volcano?: 

What is a volcano? Volcanoes are in belts along the edges ( по краям) of tectonic plates. Some tectonic plates have cracks ( трещины) – rift valleys ( долины) – which house volcanoes. A volcano is a mountain formation which erupts with lava.

Famous volcanoes: 

Famous volcanoes Krakatau in Indonesia erupted in 1883 and killed many people. Vesuvius in Italy eruped in 79 AD ( нашей эры) and destroyed Pompeii. Mount Fuji in Japan is a beautiful volcano. Tambora in Indonesia erupted in 1815 and killed 82,000 people.

PowerPoint Presentation: 

Volcanoes erupt with lava , ash ( пепел) , pumice ( пемза) , gas (carbon dioxide – углекислый газ) and rocks . E.g. there is a volcanic lake in Africa – Lake Nyos – which killed 1,700 people with a gas cloud in 1986.

PowerPoint Presentation: 

Conical volcano (конический вулкан) : basalt. Formed by thick lava which cooled very quickly. Shield volcano ( щитовой вулкан) : formed by fluid lava which cooled very slowly.

Volcanic bombs: 

Volcanic bombs When the lava plug (лавовая пробка) blocks the vent ( жерло) and the underground pressure gets big, magma and gas explode.

PowerPoint Presentation: 

This explosion forms a hole. This hole is called caldera ( кальдера (круглое или овальное углубление в конце жерла вулкана).

Types of volcanoes: 

Types of volcanoes Volcanoes can be Extinct (потухший) Active ( действующий) In Russia there are many active volcanoes in Kamchatka and the Kuril isles. The biggest is Klyuchevskaya Sopka in Kamchatka. It is 4688 meters high.

Geysers: 

Geysers There is a lot of hot water, gas and mud in the underground. The water in the underground cavities ( подземные полости) are heated by the mantle. Pressure grows ( давление растет) and the steam ( пар) comes out.

Earthquakes: 

Earthquakes Earthquakes happen when two tectonic plates slide ( скользят) past each other. Seismic active areas are areas where earthquakes happen very often. The focus ( очаг) of the earthquake is the place when the tectonic plates meet. The epicentre is the place on the earth where the earthquakes is most destructive.

The Pacific Ring of Fire: 

The Pacific Ring of Fire is an area where many earthquakes and volcanic eruptions happen in the Pacific Ocean . he Ring of Fire has 452 volcanoes. The Ring of Fire is a result of movement of tectonic plates.

Volcanoes in Russia: 

Volcanoes in Russia The Kamchatka Peninsula ( полуостров) is in the Far East ( Дальний Восток) . There are two volcanic belts here and 30 active volcanoes : Klyuchevskaya Sopka Kamen Tolbachik Ushkovsky Ichinsky