Volcanoes Multiple Choice Test

Earth's Crust and Volcanic Eruptions

• The 18-mile thick layer of solid rock that we live on is called the lithosphere.
• When two of the Earth's plates move together, they can collide and cause the Earth's surface to buckle, forming mountains or volcanoes.
• Gas bubbles inside magma grow bigger when the pressure on them decreases, causing them to expand.
• A volcano erupts when the pressure of the gas bubbles in the magma becomes too great, causing the magma to burst out of the ground.
• When magma is runny and gas can escape easily, a gentle eruption is expected.
• Knowing about the Earth's crust is important for understanding volcanic eruptions because it helps us understand the movement of tectonic plates and the formation of volcanoes.
• The term used for molten rock that flows from a volcano is lava.
• The smallest pyroclasts thrown from a volcano are called ash.
• Volcanoes formed by runny lava spreading out over a wide area are called shield volcanoes.
• Mount Fuji is an example of a strato-volcano.
• Crater Lake in the United States was formed by a massive volcanic eruption that caused the volcano to collapse.