VOLCANOES

WHAT IS A VOLCANO?

A volcano is a mountain that forms when magma escapes the through the crust and cools.

WHY DOES MAGMA COME TO THE SURFACE?

Magma comes to the surface because it is less dense then the rock. Remember, substances of lesser density float on top of more dense items.

WHAT ARE THE PARTS OF A VOLCANO?

Magma chamber : The large

underground pool of liquid rock found beneath the surface of the Earth

Main Vent: A point

source of the Earth's surface where lavas ash and gas are erupted. 

Lava: Molten rock

that reaches the earth's surface through a volcano 

Crater: a bowl-

shaped formation at the top of a volcano.

Layers of Ash and Lava: As ash

settles and lava cool, more and more layers accumulate.

Secondary Cone: A second

opening to the volcano attached to the main tube, allowing gas, ash and lava to escape.

ARE ALL VOLCANOES ALIKE?

Is wide and flat.

It forms from a quiet eruption.

Lava flows out quietly and for great distances

SHIELD VOLCANO

Has tall, very steep sides.

Has explosive eruptions.

This eruption produces a lot of cinder and ash.

CINDER CONE VOLCANO

Form from explosive eruptions.

Produce a lot of lava and ash.

Is small, with steep sides.

COMPOSITE VOLCANO