Earth’s Changing Structures SSA Review 5 – Earth’s Changing Structures

Earth’s Interior Layer Depth Temp Description Crust 3 – 25 miles Solid rock, covered with land and oceans. Up to 230° F

Earth’s Interior Layer Depth Temp Description Mantle Goes down to 1,800 miles From 230° to 4400° F Made of rock material Lithosphere * top part (25 - 60 miles) * solid rock * combines with the crust Asthenosphere * below the lithosphere * 60-120 miles below the Earth’s surface *hot, melted rock (magma)

Convection in the Earth’s Mantle https://www.youtube.com/watch?v=ryrXAGY1dmE

Earth’s Interior Layer Depth Temp Description Core Goes down to 3,900 miles 4,400 to 10,000°F Made of metal: nickel and iron. Outer core * 1,800-3,100 miles below Earth’s surface *liquid metal As hot as the sun Inner core *3,100-3900 miles below Earth’s surface *solid ball of metal *very high pressure

Mid-ocean Ridge – an underwater chain of mountains along the ocean floor. *35,000 miles long

Sea-floor spreading: at the mid-ocean ridge, magma rises from the mantle and erupts. The lava spreads out, pushing older seafloor away from the ridge, adding new rock material to the ocean floor. https://www.youtube.com/watch?v=sgDM6m0lUGY&index=8&list=PLK5QnX_5Gp3WGL-fJivkzK_dhtUcd0ZZF

Subduction - The process where the ocean floor sinks into a trench and down into the mantle. Ocean trench - An underwater canyon that forms where the Oceanic crust sinks downward.

Plate Boundaries – the cracks that separate the Earth’s tectonic plates Juan de Fuca Plate Phillipine Plate Cocos Plate

Types of Plate Boundaries Name Description Two plates sliding past one another at a fault ( a crack in the Earth’s crust.) 1-Transform *Earthquakes occur along these boundaries.

Rift valleys form at divergent boundaries on land. Description Name 2 - Divergent Two plates moving apart from one another. *Divergent boundaries in the ocean occur at the mid-ocean ridge. (Sea-floor Spreading) Rift valleys form at divergent boundaries on land.

Description Name 3 - Convergent Two plates moving into one another. *Oceanic plates sink into a trench. Most volcanoes form here.

Name Description Two plates moving into one another. Convergent *Mountains form when two continental plates collide and the land pushes upward.