Chapter 4 - Volcanoes

Question 1

Volcano

Answer 1

Openings in the earths surface through which magma, ash, cinder and gas erupt

Question 2

Formation of a volcano

Answer 2

1. Magma seeps up from the magma reservoir in the mantle through cracks in the crust. When pressure builds up near the surface, this causes an eruption that fires gas, ash and cinders up into the sky.
2. The magma is called lava at the surface. It flows out of the crater at the top and flows down the sides and hardens.
3. Layers of lava and ash build up during eruptions to form a cone shaped volcano.
4. Sometimes a secondary volcano forms on the cone.

Question 3

The mid-Atlantic ridge

Answer 3

Occurs in the middle of the Pacific Ocean where the North American and Eurasian plate are separating. This is called seafloor s