Unit 4 Test Review - Fhs Earth Science

Front 1

Aa

Back 1

lava that hardens into rough, jagged rocks with a crumbly texture

Front 2

asthenosphere

Back 2

the solid, plastic layer of the mantle beneath the lithosphere

Front 3

caldera

Back 3

a large, circular depression that forms when the magma chamber below a volcano empties

Front 4

cinder cone

Back 4

very steep edges; rarely more than a few hundred meters high; form from small, explosive eruptions

Front 5

composite (stratovolcano)

Back 5

form from alternating layers of hardened lava flows and pyroclastic material; example includes Mt. St. Helens

Front 6

continental drift

Back 6

continents have drifted to their present location; the movement of continents

Front 7

convection current

Back 7

movement of a matter due to differences in density that are caused by temperature variations

Front 8

convergent boundary

Back 8

the boundary between tectonic plates that are colliding

Front 9

crater

Back 9

top section of a volcano where the eruption typically occurs from

Front 10

divergent boundary

Back 10

the boundary between two tectonic plates that are moving away from each other

Front 11

earthquake

Back 11

a movement or trembling of the ground that is caused by a sudden release of energy when rocks along a fault move

Front 12

epicenter

Back 12

point on Earth's surface directly above an earthquake's starting point, or focus

Front 13

fault zone

Back 13

a region of numerous, closely spaced faults

Front 14

focus

Back 14

the location within Earth along a fault at which the first motion of an earthquake occurs

Front 15

hot spot

Back 15

a volcanically active area of Earth's surface, far from a tectonic plate boundary

Front 16

intensity

Back 16

the amount of damage caused by an earthquake

Front 17

L-Wave

Back 17

last seismic waves, are slowest and most damaging to structures

Front 18

lava

Back 18

magma that flows onto the Earth's surface

Front 19

lithosphere

Back 19

the solid, outer layer of Earth that consists of the crust and the rigid upper part of the mantle

Front 20

magma

Back 20

liquid rock produced under the Earth's surface

Front 21

magma chamber

Back 21

an underground pool of molten rock; feeds the volcano

Front 22

magnitude

Back 22

a measure of the strength and energy released during an earthquake

Front 23

Mercalli Scale

Back 23

scale that measures an earthquake's damage

Front 24

mid-ocean ridge

Back 24

a long, undersea mountain chain formed at divergent plate boundaries

Front 25

P wave

Back 25

a primary wave, or compression wave

Front 26

Pahoehoe

Back 26

lava that hardens to form smooth, ropelike coils, pillowy and smooth when it hardens

Front 27

Pangea

Back 27

supercontinent that formed 300 million years ago and that began to break up 200 million years ago

Front 28

Panthalassa

Back 28

single, large ocean that covered Earth's surface during the time the supercontinent Pangea existed

Front 29

plate tectonics

Back 29

theory that explains that Earth's crust is broken into pieces

Front 30

pyroclastics

Back 30

fragments of rock and ash that form during a volcanic eruption, hot and fast moving

Front 31

Richter Scale

Back 31

scale that measures earthquake's strength, or magnitude, or energy

Front 32

rift valley

Back 32

long, narrow depression that forms within a mid-ocean ridge

Front 33

S wave

Back 33

a secondary seismic wave that causes particles to move in a side-to-side direction

Front 34

sea-floor spreading

Back 34

process by which new oceanic land forms as magma rises to Earth's surface at a mid-ocean ridges at divergent plate boundaries

Front 35

seismogram

Back 35

the recorded waves of an earhquake

Front 36

seismograph

Back 36

an instrument that records vibrations in the ground

Front 37

shield volcano

Back 37

broad at the base and have gently sloping sides; generally formed by quiet, non-explosive eruptions; example is Kilauea in Hawaii

Front 38

subduction zone

Back 38

the region where an oceanic plate sinks down and melts at a convergent boundary

Front 39

supercontinent cycle

Back 39

the process by which supercontinents form and break apart over millions of years

Front 40

transform boundary

Back 40

the boundary between tectonic plates that are sliding past each other horizontally

Front 41

tsunami

Back 41

a giant ocean wave that forms after an earthquake

Front 42

Types of Convergent Boundaries

Back 42

ocean to ocean

ocean to continent

continent to continent

Front 43

volcano

Back 43

a vent or fissure in the Earth's surface through which magma and gases are expelled