Plate Tectonics Flashcards
What are plate tectonics?
Plates are pieces of the lithosphere that move around
What are Hot spots?
A hot spot is an intensely hot area in the mantle below Earth’s crust; a volcanically active area of Earth’s surface far from tectonic plate boundaries
What is a earthquake?
movements or trembling of the ground that is caused by a sudden release of energy when rocks along a fault move
What is a fault?
a break in a body of rock along which one block slides relative to another
What is a fault zone?
a region of numerous, closely spaced faults
What is seismology?
the study of earthquakes and seismic waves
What is a seismograph?
an instrument that records vibrations in the ground
What is a seismogram?
a tracing of earthquake motion that is recorded by a seismograph
What are seismic waves?
vibrations caused by the release of energy along a fault
What are P waves?
primary waves/compression waves; Fastest, first to be detected; Can move through solids, liquids, and gases; Causes particles of rock to move in a back-and-forth in direction that is parallel; Travel in the direction that the waves are traveling; The more rigid the material, the faster the waves move
What are S waves?
secondary waves/shear waves; move up and down; can only move through liquids; slower then primary waves
What is deformation?
the bending, tilting, and breaking of Earth’s crust in response to stress
What is a fold?
A bend in rock layers from stress
What is an epicenter?
the point on the Earth’s surface directly above an earthquake’s starting point (focus)
What is intensity?
The amount of damage caused by an earthquake
What is the continental crust?
Located beneath land masses and under shallow seas close to continents; very thick and lighter rock
What is the oceanic crust?
Located beneath deep ocean; very thin; dense heavy rock
What are divergent plate boundaries?
When two plates move away from each other
What are convergent plate boundaries?
When two plates collide
What are transform plate boundaries?
When two plates move past each other horizontally
What kind of crust does a divergent plate boundary occur in?
They can occur in continental or oceanic crust
What are the different types of convergent plate boundaries?
Continental-Continental; OCEANIC-OCEANIC; Continental-Oceanic
What is intensity?
The amount of damage an earthquake causes
What is pyrolastic material?
Fragments of rock that form during a volcanic eruption
What gases are released in a volcano?
Sulfur dioxide, Carbon dioxide, and water vapor.
What is a crater?
A funnel shaped pit at the top of a volcano
What plate boundary causes volcanoes?
Convergent plate boundaries
What plate boundary causes earthquakes?
Convergent plate boundaries
What are oceanic to continental plates?
The denser plate moves beneath the less dense plate. Oceanic plates are denser than continental plates.
What are oceanic to oceanic plates?
The densest plate will subduct and a deep ocean trench forms.
What are continental to continental plates?
when two continental plates collide, they just smash together; rift valley forms
Are hot spots on plate boundaries?
No
What are mantle plumes?
A stationary area of high heat flow in the mantle
What is a thrust fault?
the upper block, above the fault plane, moves up and over the lower block
What is a reverse fault?
the block above the fault moves up relative to the block below the fault.
What is a strike slip fault?
occur along the boundaries of plates that are sliding past each other; rock slides horizontally in response to shear stress
What kind of plate boundaries are normal and strike slip faults?
Divergent boundaries
What kind of plate boundaries are reverse and thrust faults?
Convergent boundaries
What is a normal fault?
the hanging wall moves downward relative to footwall
