The Changing Earth The Changing Earth

continental drift theory movement of the continents over time

movement of the earth’s crust plate tectonics movement of the earth’s crust

Plate Movement The earth’s plates move 5 different ways 1) spreading: moving apart 2) subduction: diving under another plate 3) collision: crashing into one another 4) sliding: sliding past each other, side to side 5) folding: a process that causes a bend/fold in a layer of rock

fault – a break in the earth’s crust subduction zone – where one of the earth’s plates slides under another

Earthquake – Violent movement of the earth along faults Seismograph – measures the intensity of earthquakes Focus – the point in the earth where an earthquake begins Epicenter – the point on the surface above the focus of an earthquake Richter scale – used to determine the relative strength of an earthquake Tsunami – A giant wave in the ocean

volcanic activity involving the flow of magma or molten rock volcanism volcanic activity involving the flow of magma or molten rock

The Ring of Fire A zone around the rim of the Pacific Ocean where the majority of active volcanoes are located

magma – melted rocks contained in pockets in the earth’s mantle lava – molton rock on the earth’s surface

Caldera A large, bowl-shaped volcanic depression

Forces that Change the Earth’s Surface Weathering Erosion Deposition

Weathering: breaking down of rocks at or near the earth’s surface Weathering: breaking down of rocks at or near the earth’s surface. Erosion: The wearing away of land or soil by the action of wind, water, or ice. Deposition: Process by which sediments are deposited in a new location, usually by wind or water.