Volcanoes Eruptions and Impacts What are volcanoes Does

Volcanoes: Eruptions and Impacts

What are volcanoes? • Does anyone know what a volcano is? • A volcano is a landform (usually a mountain) where liquid rock erupts through the surface of the planet. • The name "volcano" has its origin from the name of Vulcan, a god of fire in Roman mythology. https: //www. youtube. com/watch? v=TVR_Xfe. DCjk

Where do you find volcanoes? • The Earth’s crust is cracked into tectonic plates. These plates ‘float’ on the mantle. • Sometimes these plates collide and sometimes they diverge.

• https: //www. youtube. com/watch? v=Kdv. GI 1 r_OTU

Constructive Plate Boundaries

Destructive Plate Boundaries

Hotspot Volcanoes

Parts of a volcano Main Vent Secondary vent Ash Cloud Crater Lava Layers of lava and ash Magma Chamber

Parts of a volcano Ash Cloud Crater Lava Secondary vent Layers of lava and ash Main Vent Magma Chamber

Do all volcanoes erupt all the time? • Volcanoes can be described as: • Active- a volcano that erupts regularly • Dormant- is an active volcano that is not erupting, but supposed to erupt again • Extinct- has not had an eruption for at least 10, 000 years and is not expected to erupt again in a comparable time scale of the future

Active Mauna Loa - Hawaii

Dormant Vesuvius - Italy

Extinct Volcano O’Leary Peak - Arizona

Types of Volcanoes • Composite volcanoes are steep-sided and cone-shaped, made up of layers of ash and lava and containing sticky lava which doesn't flow very far.

Types of Volcanoes • Shield volcanoes have gently sloping sides and runny lava that covers a wide area. Gases escape very easily from shield volcanoes. This makes eruptions less violent.

During an eruption… • Gases and lava are expelled from the vent. As well as volcanic bombs • Depending on the type of volcano the characteristic of the eruption will be different. • Pyroclastic flows are common at composite cone volcanoes, they are a superheated mixture of steam and rocks that rolls down the slides of a volcano at high speed.

Impacts Positive Negative The dramatic scenery created by volcanic eruptions attracts tourists Many lives can be lost as a result of a volcanic eruption. Very fertile soil in the area surrounding the volcano which is good for agriculture Lahars The high level of heat and activity inside the Earth, close Lava flows and lahars can destroy settlements and clear to a volcano, can provide opportunities for generating areas of woodland or agriculture. geothermal energy. Human and natural landscapes can be destroyed and changed forever.

• https: //www. youtube. com/watch? v=U 1 p. Gxu. Wy. Kfo

Summary • Composite Cone volcanoes are steep sided and tend to have explosive eruptions • Shield Volcanoes have gentle slopes and runny lava • Volcanoes can destroy infrastructure and settlements, and lives can be lost • Volcanoes can provide fertile soils and dramatic scenery which can bring income to the areas surrounding them.

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