Geol 1121 Exam 2

Front 1

Broad, relatively flat regions of the ocean that lie at a depth of about 5 km below sea level

Back 1

Abyssal Plains

Front 2

Elongate submarine mountain ranges whose peaks lie only about 2 - 2.5 km below sea level

Back 2

Mid - ocean Ridges

Front 3

Deep areas in elongate troughs where the ocean floor reaches depths of 8 - 12 km

Back 3

Deep - ocean Trenches

Front 4

Curving chains of active volcanoes bordering trenches

Back 4

Volcanic Arcs

Front 5

Once active volcanoes located below sea level; isolated submarine mountains.

Back 5

Sea Mounts

Front 6

Narrow bands of vertical cracks and broken up rock; lie at roughly right angles to mid - ocean ridges

Back 6

Fracture Zones

Front 7

Layer of the earth which consists of the crust and the top (cooler part) of the upper mantle

Back 7

Lithosphere

Front 8

Layer of earth the lithosphere flows on; composed of warmer mantle that can flow slowly when acted on by force.

Back 8

Athenosphere

Front 9

Lithosphere that ranges from 25 - 70 km in thickness and consists of relatively low density felsic and intermediate rocks.

Back 9

Continental lithosphere

Front 10

Lithosphere that ranges from 7 - 10 km in thickness and consists of relatively high density mafic rocks.

Back 10

Oceanic Lithosphere

Front 11

A plate boundary in which two plates move apart from one another

Back 11

Divergent Boundary

Front 12

A plate boundary in which two plates move toward each other so that one plate sinks beneath the other

Back 12

Convergent Boundary

Front 13

A plate boundary at which one plate slips along the side of another plate

Back 13

Transform Boundary

Front 14

The plate boundary activity which results in the formation of mid - ocean ridges

Back 14

Divergent Boundary

Front 15

A zone at a convergent boundary where one plate (usually oceanic) sinks beneath another plate, into the athenosphere

Back 15

Subduction Zone

Front 16

Zone name for the belt of earthquakes that occur in a downgoing plate

Back 16

Wadati-Benioff Zone

Front 17

Earthquakes cannot occur at a depth greater than this

Back 17

660 km

Front 18

Stationary volcanoes or areas of hot magma located in the middle of plates, not along boundaries.

Back 18

Hot Spots

Front 19

The source for hot spots; a column of very hot rick rising up through the mantle to the base of the lithosphere.

Back 19

Mantle Plume

Front 20

The chain of extinct volcanoes formed when an overlying plate moves over a fixed plume.

Back 20

Hot Spot Track

Front 21

The process by which new divergent plate boundaries are formed and one continent separates into two continents

Back 21

Rifting

Front 22

The process by which a convergent boundary ceases to exist when a piece of buoyant lithosphere moves into the subduction zone

Back 22

Collision

Front 23

A linear belt in which continental lithosphere undergoes rifting, or pulls apart. The lithosphere stretches horizontally, so it thins vertically. Near the surface of the continent, brittle rocks stretches and breaks, forming faults.

Back 23

Continental rift

Front 24

The process by which two buoyant pieces of lithosphere converge and squeeze together

Back 24

Collision

Front 25

Develops because the region of a rift is elevated, so the mass of the ridge pushes sideways

Back 25

Ridge-Push Force

Front 26

Develops because lithosphere is denser than the underlying athenosphere and sinks like a stone in water.

Back 26

Slab-Pull Force

Front 27

Seismic waves that pass through the center of the earth

Back 27

Body waves

Front 28

Seismic waves that travel along earth's surface

Back 28

Surface waves

Front 29

Seismic waves that cause particles of material to move back and forth parallel to the direction the wave itself moves (compression and dilation)

Back 29

Compressional waves

Front 30

Seismic waves that cause particles of material to move perpendicular to the direction the wave itself moves

Back 30

Shear waves

Front 31

P-Waves (primary)

Back 31

Compressional Body Waves

Front 32

S-Waves (secondary)

Back 32

Shear Body Waves

Front 33

L-Waves (love)

Back 33

Surface waves that cause the ground to ripple back and forth, producing a snake like movement

Front 34

R-Waves (rayleigh)

Back 34

Surface waves that cause the ground to ripple up and down

Front 35

Fastest waves; travel in same direction as principal direction of force; travel through all material

Back 35

P-Waves

Front 36

Travel perpendicular to primary direction of force; will not travel through liquid/molten materials

Back 36

S-Waves

Front 37

The waves that we feel; cause shaking and damage to buildings.

Back 37

L-Waves (surface waves)

Front 38

The phenomenon resulting in waves bending as they travel through layers of varying density

Back 38

Wave refraction

Front 39

Waves move _____ through higher densities

Back 39

Faster

Front 40

Scale for determining the magnitude based on the damage is causes; from 1 - 12.

Back 40

Mercalli Intensity Scale