Plate Tectonics

Front 1

Continental Drift

Back 1

The hypothesis that states that the continents once formed a singlelandmass, broke up, and drifted to their present locations.

Front 2

Convection Currents

Back 2

___Transfer of thermal energy from warmer regions ofmagma below the crust to cooler regions.

Front 3

Lithosphere

Back 3

A rigid layer made up of the upper most part of the mantle and thecrust.Oceanic crust.

Front 4

Seafloor Spreading

Back 4

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.

Front 5

Tectonic Plate

Back 5

_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.

Front 6

Asthenosphere

Back 6

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.

Front 7

Plate Tectonics

Back 7

A theory stating that the earth’s surface is broken into plates that move.

Front 8

Converging plate boundary

Back 8

A plate boundary where two plates move toward eachother.

Front 9

Diverging plate boundary

Back 9

A boundary where the plates are moving AWAY from eachother.

Front 10

Mid-ocean ridge

Back 10

An underwater mountain chain where new ocean floor is formed.

Front 11

Moho/Mohorovicic discontinuity

Back 11

the zone between the crust and mantle that marks aboundary between the 2, discovered because it changes the speed of seismic waves.

Front 12

Ocean trench

Back 12

very deep, elongated cavity bordering a continent or an island arc.

Front 13

Pangaea

Back 13

A supercontinent containing all of Earth’s land that existed about 225 millionyears ago.

Front 14

Rift Valley

Back 14

When continental crust begins to separate, the split crust forms a longnarrow depression.

Front 15

Subduction zone

Back 15

One plate going under another plate.

Front 16

Transform Boundary

Back 16

The boundary between tectonic plates that are sliding past eachother horizontally.

Front 17

Fault

Back 17

A break in the earth’s crust.

Front 18

Folding

Back 18

A bend in layers of rock

Front 19

Normal Fault

Back 19

A type of fault where the hanging wall slides downward caused bytension in the crust.

Front 20

P-waves / Primary wave

Back 20

primary earthquake waves travel the fastest.

Front 21

Reverse fault

Back 21

A type of fault where the hanging wall slides upward caused bycompression in the crust.

Front 22

Seismic waves

Back 22

Vibrations of the ground during an earthquake.Thrust Faults- a reverse fault in which the hanging wall slides over the foot wall.

Front 23

S-waves / Shear wave

Back 23

secondary earthquake waves only goes through solids.

Front 24

Stricke-Slip Fault

Back 24

A type of fault where rocks on either side move past each othersideways with little up or down motion.

Front 25

Stress

Back 25

A force that acts on rock to change its shape or volume.

Front 26

Compression

Back 26

stress that squeezes rock until it folds or breaks.

Front 27

Tension

Back 27

stress that stretches rock so that it becomes thinner in the middle.

Front 28

Anticline

Back 28

A fold in rock that beds upward into an arch

Front 29

Syncline

Back 29

A downward fold in rock formed by compression in Earth’s crust.

Front 30

Earthquake Focus

Back 30

The point where slippage first occurs under the Earth’s surface wherean earthquake originates.

Front 31

Epicenter

Back 31

the point on Earth’s surface directly above the focus of an earthquake.

Front 32

Hot Spots

Back 32

Volcanoes located far from plate boundaries caused by unusually thin areas ofcrust where hot magma is able to push through the surface.

Front 33

Magnetic Reversal

Back 33

A change in the Earth’s magnetic field.

Front 34

Modified Mercalli Intensity Scale

Back 34

A scale that rates earthquakes according to theirintensity and how much damage they cause at a particular place.

Front 35

Richter Scale

Back 35

A logarithmic scale of 1 to 10 used to express the energy released by anearthquake.

Front 36

Magnitude

Back 36

Measure of the energy released during an earthquake, which can bemeasured/described using the Richter Scale.

Front 37

Viscosity

Back 37

The resistance of a substance to flow (i.e. water has a lower viscosity thanmaple syrup)

Front 38

Ridge Push

Back 38

The process in which new material at a ridge or rift pushes older materialaside, moving the tectonic plates away from the ridge.

Front 39

Gravity Pull

Back 39

dense oceanic crust sink into the subduction zone and pulls the whole crustwith it.

Front 40

Lava

Back 40

Magma that reaches Earth’s surface

Front 41

Magma

Back 41

Molten rock beneath the earth’s surface

Front 42

Cinder Cone

Back 42

a short, steep, cone-shaped hill or small mountain made of volcanic ash,cinders, and bombs piled up around a volcano’s opening.

Front 43

Composite Volcano or Stratovolcano

Back 43

tall explosive volcano characterized by highviscosity magma and large amounts of trapped gas.

Front 44

Shield Volcano

Back 44

A low, flat, gently sloping volcano built from many flows of fluid, low-viscosity basaltic lava.

Front 45

Tephra

Back 45

Rock fragments thrown into the air during a volcanic eruption.

Front 46

Ring of Fire

Back 46

A major belt of volcanoes that rims the Pacific Ocean.