In Black and White

Volcanoes occur where weaknesses in the earth’s crust allow magma, ash, gas and water to erupt onto the land and seabed.

Volcanoes appear when two plates collide together, the thinner plate is pushed downwards causing earth to be pushed up to the crust, because of the intense friction and pressure happening when the plates collide the rocks melt to become magma, as they push together the magma is forced up to the crust.

Types of Volcanoes

Volcanoes aren’t just mounds spraying lava everywhere, some haven’t seen any activity in thousands of years:

Active: Active volcanoes that have erupted recently.

Dormant: Volcanoes that have not erupted for a long period of time.

Extinct: Volcanoes that are no longer areas of tectonic activity, no record of volcanic activity since records began.

Volcanoes appear when two plates collide together, the thinner plate is pushed downwards causing earth to be pushed up to the crust, because of the intense friction and pressure happening when the plates collide the rocks melt to become magma, as they push together the magma is pushed up to the crust.

Example Characteristics of a Volcano (Soufriere Hills, Montserrat)

1. Thinner plate is driven beneath thicker continental plate as the plates converge.
2. Rocks of Oceanic Plate melt in high temperatures below the earths crust, creating liquid magma which is forced up through joints and weaknesses int he rock.
3. Build up of pressure over a long period of time finally released in volcanic eruption.
4. Mudflows occur – mixtures of ash and water travel at great speed for many kilometres.
5. Clouds of gas, steam and dust rise high into the atmosphere.
6. Thick layers of ash bury the surrounding areas.

What are the Rsks of Volcanoes?

Lava flows are the most commonly knows deposit of volcanoes. Lava flows are molten rock flowing down the sides of a volcano.

Lahars are mudflows, mixtures of ash and water travel at great speeds down the mountain sides.

Dust and ash clouds are thrown high into the atmosphere. Upon settling ash can completely cover buildings and crops.

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