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science ch 4 vocab
Chapter 4 Vocab
Term | Definition |
---|---|
asthenosphere | The soft layer of the mantle on which the lithosphere floats. |
colliding boundary | A plate boundary where two plates move toward each other. |
conduction | The direct transfer of thermal energy from one substance to another substance that it is touching. |
continental drift | The hypothesis that the continents slowly move across Earth's surface. |
convection | The transfer of thermal energy by the movement of a fluid. |
convection current | The movement of a fluid, caused by differences in temperature that transfers heat from one part of the fluid to another. |
crust | The layer of rock that forms Earth's outer surface. |
deep-ocean trench | A deep valley along the ocean floor beneath which oceanic crust slowly sinks toward the mantle. |
density | The amount of mass of a substance in a given volume; mass per unit volume. |
fault | A break or crack in Earth's lithosphere along which the rocks move. |
fossil | A trace of an ancient organism that has been preserved in rock. |
inner core | A dense sphere of solid iron and nickel at the center of Earth. |
lithosphere | A rigid layer made up of the uppermost part of the mantle and the crust. |
mantle | The layer of hot, solid material between Earth's crust and core. |
mid-ocean ridge | An undersea mountain chain where new ocean floor is produced. |
outer core | A layer of molten iron and nickel that surrounds the inner core of Earth. |
Pangaea | The name of the single landmass that broke apart 200 million years ago and gave rise to today's continents. |
plate | A section of the lithosphere that slowly moves over the astenosphere, carrying pieces of continental oceanic crust. |
plate tectonics | The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle. |
pressure | The force exerted on a surface divided by the total area over which the force is exerted. |
radiation | The direct transfer of energy through space by electromagnetic waves. |
rift valley | A deep valley that forms where two plates move apart. |
sea-floor spreading | The process by which molten material adds new oceanic crust to the ocean floor. |
seismic waves | Vibrations that travel through Earth carrying the energy released during an earthquake. |
sliding boundary | A place where two plates slip past each other, moving in opposite directions. |
sonar | A device that determines the distance of an object under water by recording echoes of sound waves. |
spreading boundary | The place where two plates move apart. |
subduction | The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary. |