Unit at a Glance Chapter 9: Volcanoes Standards S6E5: Students will investigate the scientific view of how the earth’s surface is formed. a. Compare and contrast the Earth’s crust, mantle and core including temperature, density, and composition. d. Recognize that lithospheric plates constantly move and cause major geological events on the Earth's surface. e. Explain the effects of physical processes (plate tectonics, erosion, deposition, volcanic eruption, gravity) on geological features including oceans (composition, currents, and tides). Unit Vocabulary Volcano: a vent or fissure (split) in the Earth’s surface through which magma and gasses are expelled. Vent: an opening at the surface of the Earth through which volcanic material passes. Magma: hot, molten rock beneath the Earth’s surface. Lava: magma that flows onto the Earth’s surface. Pyroclastic Material: material including ash and large blocks of rock that are blasted into the air during an explosive volcanic eruption. Ash: dust-sized particles of hardened lava. Crater: the funnel-shaped pit near the top of the central vent of a volcano. Caldera: a large, semicircular depression that forms when the magma chamber below a volcano partially empties and causes the ground above to sink. Lava Plateau: a wide, flat landform that results from the repeated nonexplosive eruptions of lava that spread out over a large area. Rifts: long cracks in the Earth’s crust. Rift Zone: an area of deep cracks that form between two tectonic plates that are pulling away from each other. Mid-Ocean Ridge: a long, undersea mountain chain that forms along the floor of the world’s major oceans. Divergent Boundary: where two tectonic plates separate or divide. Hot Spot: a volcanically active area on the Earth’s surface that is far from a tectonic plate boundary. Unit at a Glance Convergent Boundary: where two tectonic plates collide. Mantle Plume: a column of magma that rises from deep within the Earth. Essential Questions 1. What are the two types of volcanic eruptions? 2. What are the parts of a volcano? 3. What are some things that come out of a volcano when it erupts? 4. What effects can eruptions have on our planet? 5. What are the three different types of volcanoes and volcanic landforms? 6. What can cause magma to form? 7. Where can volcanoes form?