Plate Tectonics Vocab Flashcards
Plate Tectonics
the theory that the Earth’s lithosphere is divided into tectonic plates that move around on top of the asthenosphere
Lithosphere
the solid, outer layer of the Earth that consists of the crust and the rigid upper part of the mantle
Asthenosphere
the soft layer of the mantle on which pieces of the lithosphere move. Tectonic plates, parts of the lithosphere “float” or move on this layer
Mesosphere
the strong, lower part of the mantle between the asthenosphere and the outer core
Outer Core
the liquid layer of the Earth’s core that lies beneath the mantle and surrounds the inner core
Inner Core
a dense sphere of solid iron and nickel at the center of the Earth
Mantle
the thick layer of rock between Earth’s crust and core
Mid-Ocean Ridge
an underwater mountain chain where new ocean floor is formed
Subsidence
the sinking of regions of Earth’s crust to lower elevations
Uplift
a rise of land to a higher elevation (as in the process of mountain building)
Stress
a force that acts on rock to change its shape or volume
Ring of Fire
area around the Pacific Ocean known for frequent earthquakes and volcanoes
Hot Spot
volcanoes far from tectonic plate boundaries
Sea-Floor Spreading
when two oceanic plates pull apart, magma rises and new crust is formed
Rift Zone
an area of deep cracks that forms between two tectonic plates that are pulling away from each other
Oceanic Crust
Earth’s crust located under the ocean that is usually thinner but more dense than continental crust
Continental Crust
part of Earth’s crust that contains all continents and major islands, it is thicker and less dense than oceanic crust
Fault
a break or crack in Earth’s crust where masses of rock slip past each other
Boundary
an area where 2 tectonic plates meet
Layers of the Earth
lithosphere, asthenosphere, mesosphere, outer core, and inner core
Tectonic Plates
pieces of the lithosphere that move around on top of the asthenosphere. They can be made up of continental crust, oceanic crust, or a combination of both types of crust
Convection
hot rock deep within the Earth rises at a boundary that has less pressure, cools toward the surface, and sinks
Strike-Skip Fault
a fault in which the two fault blocks move past each other horizontally
Convergent Boundary
a plate boundary where 2 plates move toward each other. Can cause the formation of mountains
Transform Boundary
the boundary between tectonic plates that are sliding past each other horizontally- can cause earthquakes
Tension
stress that stretches rock so that it becomes thinner in the middle
Compression
stress that squeezes rock until it folds or breaks
Volcano
a mountain that forms when magma reaches the surface. Form along plate boundaries that move apart or collide
Earthquake
the shaking that results from the movement of rock beneath the Earth’s surface. Happen at the edges of tectonic plates or faults
Continental Drift
the theory that continents can drift apart from one another and have done so in the past
Divergent Boundary
a plate boundary where two plates move away from each other
Pangaea
single large landmass made up of all the continents connected together that broke apart 200 million years ago
Crust
the thin and solid outermost layer of earth above the mantle
