Chapter 3: Volcanoes---Section 1: Volcanoes and Plate Tectonics

What features form as an oceanic plate moves across a hot spot?

Series of Volcanic mountains

Island Arc

a string of islands formed by volcanoes along a deep-ocean trench.

Lava

Liquid magma that reaches the surface: also the rock formed when liquid lava hardens.

Ring of Fire

A major belt of volcanoes that rims the pacific ocean

Hot Spot

A plume of magma that has broken through earth's crust

How does a hot spot volcano form?

A volcano forms above a hot spot when magma erupts through the crust and reaches the surface

Where are most volcanoes located?

Along diverging and converging plate boundaries

Magma

The molten mixture of rock-forming substances, gases, and water from the mantle.

Volcano

1. A weak spot in the crust where magma has come to the surface. 2. An opening in earth's crust where gas, ash, dust, and lave erupt.

What causes volcanoes to form at a divergent plate boundary?

The crust fractures as plates diverge (pull apart) allowing magma to reach the surface