How does a volcano erupt? VOLCANOES How does a volcano erupt? VOLCANIC LANDFORMATIONS VOLCANOES AND PLATE TECTONICS VOLCANIC ERUPTIONS

RING OF FIRE One major belt of volcanoes. It includes the many volcanoes that rim the Pacific Ocean.

ISLAND ARC Many volcanoes form near converging plate boundaries, where two oceanic plates collide. Sometimes these volcanoes create a string of islands called an island arc. Volcanoes also occur where an oceanic plate is subducted beneath a continental plate.

ISLAND ARC

HOT SPOT

FORMATION OF A VOLCANO

SUBDUCTION

SHIELD VOLCANO

CINDER-CONE VOLCANO

COMPOSITE VOLCANO:Cotopaxi

Dormant Volcano. Cayambe

Island Formation. Plume Volcanism

Type of Lava: Pahoehoe

Type of Lava: Aa

Types of Lava: Aa Aa flows are emitted from the vent at high rates ranging to 50km an hour, often with much lava fountaining. They are characteristic of viscous magmas. Aa flows are animated with sporadic bursts of energy. They may push down houses, walls and forests. However, the hallmark of aa lava flows is the very rough surface it produces when it cools and solidifies.

Lava explosion hits the water in Hawaii

Pyroclastic Flow

Pyroclastic Flow

Volcanic Landformations:Caldera

Lava Plateau. Stromboli. Italy.

Crater. Erta Ale. Ethiopia

Erta Ale. Ethiopia

Parts of a Volcano

Parts of a Volcano

Volcanic Neck Magma hardens in a volcano’s pipe and the surrounding rock later wears away.

Volcanic Neck

Dikes Magma that forces itself across rock layers and hardens.

Dike

Sills Magma that squeezes between horizontal rock layers and hardens.

Dome Mountains Forms when uplift pushes a large body of hardened magma towards the surface, which eventually will become expose.

Dome Mountains

Batholiths Mass of rock form when a large body of magma cools inside the crust. Igneous intrusive ( plutonic)

Batholiths