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47 Cards in this Set
- Front
- Back
Continental Drift |
The hypothesis that states that the continents once formed a singlelandmass, broke up, and drifted to their present locations. |
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Convection currents |
Transfer of thermal energy from warmer regions ofmagma below the crust to cooler regions. |
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Lithosphere |
A rigid layer made up of the upper most part of the mantle and thecrust.Oceanic crust. |
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Seafloor spreading |
The process in which the ocean floor is extended when two platesmove apart, forming a crack where magma can rise to the surface, cooling and forming new crust |
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Tectonic plate |
The earth’s crust and rigid upper mantle are broken into enormouspieces called plates are moved by convection currents deep in the Earth’s mantle. |
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Asthenosphere |
The solid plastic layer of the mantle beneath the lithosphere, made ofmantle rock that flows very slowly, which allows tectonic plates to move on top of it. |
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Plate Tectonics |
A theory stating that the earth’s surface is broken inot plates that move. |
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Converging plate boundary |
A plate boundary where two plates move toward eachother. |
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Diverging plate boundary |
A boundary where the plates are moving away from eachother. |
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Mid-ocean ridge |
An underwater mountain chain where new ocean floor is formed. |
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Moho/Mohorovicic discontinuity |
The zone between the crust and mantle that marks aboundary between the 2, discovered because it changes the speed of seismic waves. |
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Ocean trench |
Very deep, elongated cavity bordering a continent or an island arc. |
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Pangaea |
A supercontinent containing all of Earth’s land that existed about 225 millionyears ago. |
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Rift Valley |
When continental crust begins to separate, the split crust forms a longnarrow depression. |
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Subduction zone |
One plate going under another plate. |
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Transform boundary |
The boundary between tectonic plates that are sliding past eachother horizontally. |
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Fault |
A break in the earth’s crust. |
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Folding |
A bend in layers of rock |
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Normal Fault |
A type of fault where the hanging wall slides downward caused bytension in the crust. |
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P-waves / Primary wave |
primary earthquake waves travel the fastest. |
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Reverse fault |
A type of fault where the hanging wall slides upward caused bycompression in the crust. |
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Seismic waves |
Vibrations of the ground during an earthquake. |
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Thrust Faults |
a reverse fault in which the hanging wall slides over the foot wall. |
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S-waves / Shear wave |
secondary earthquake waves only goes through solids. |
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Stricke-Slip Fault |
A type of fault where rocks on either side move past each othersideways with little up or down motion. |
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Stress |
A force that acts on rock to change its shape or volume. |
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Compression |
stress that squeezes rock until it folds or breaks. |
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Tension |
stress that stretches rock so that it becomes thinner in the middle. |
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Anticline |
A fold in rock that beds upward into an arch |
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Syncline |
A downward fold in rock formed by compression in Earth’s crust. |
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Earthquake focus |
The point where slippage first occurs under the Earth’s surface wherean earthquake originates. |
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Epicenter |
the point on Earth’s surface directly above the focus of an earthquake. |
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Hot spots |
Volcanoes located far from plate boundaries caused by unusally thin areas ofcrust where hot magma is able to push through the surface. |
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Magnetic Reversal |
A change in the Earth’s magnetic field. |
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Modified Mercalli Intensity Scale |
A scale that rates earthquakes according to theirintensity and how much damage they cause at a particular place. |
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Richter Scale |
A logarithmic scale of 1 to 10 used to express the energy released by anearthquake. |
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Magnitude |
Measure of the energy released during an earthquake, which can bemeasured/described using the Richter Scale. |
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Viscosity |
The resistance of a substance to flow (i.e. water has a lower viscosity thanmaple syrup) |
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Ridge Push |
The process in which new material at a ridge or rift pushes older materialaside, moving the tectonic plates away from the ridge. |
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Gravity pull |
dense oceanic crust sink into the subduction zone and pulls the whole crustwith it. |
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Lava |
Magma that reaches Earth’s surface |
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Magma |
Molten rock beneath the earth’s surface |
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Cinder Cone |
a short, steep, cone-shaped hill or small mountain made of volcanic ash,cinders, and bombs piled up around a volcano’s opening. |
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Composite Volcano or Stratovolcano |
tall explosive volcano characterized by highviscosity magma and large amounts of trapped gas. |
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Shield Volcano |
A low, flat, gently sloping volcano built from many flows of fluid, low-viscosity basaltic lava. |
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Tephra |
Rock fragments thrown into the air during a volcanic eruption. |
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Ring of Fire |
A major belt of volcanoes that rims the Pacific Ocean. |