Unit 2- Flash Cards

Front 1

Asthenosphere

Back 1

Zone of mantle beneath the lithosphere that consists of slowly flowing solid rock

Front 2

Continental crust

Back 2

Material that makes up landmasses

Front 3

Continental drift

Back 3

hypothesis stating that the continents once formed a single landmass, broke up, and drifted to their present locations

Front 4

convection

Back 4

transfer of heat through the movement of a fluid material

Front 5

convection current

Back 5

Movement in a fluid caused by uneven heating

Front 6

convergent boundary

Back 6

Border formed by the direct collision of two lithospheric plates

Front 7

divergent boundary

Back 7

Boundary formed by two lithospheric plates that are moving part

Front 8

island arc

Back 8

Chain of volcanic islands formed along an ocean trench

Front 9

lithosphere

Back 9

Thin outer shell of the earth consisting of the crust and the rigid upper mantle

Front 10

Mid-Atlantic ridge

Back 10

Undersea mountain range with a steep, narrow valley along its center

Front 11

Mid-ocean ridges

Back 11

System of undersea mountain range that wind around the earth

Front 12

Ocean trench

Back 12

deep valley in the ocean floor that forms along a subduction zone

Front 13

Oceanic crust

Back 13

Material that makes up the ocean floor

Front 14

Pangaea

Back 14

single landmass thought to have been the origin of all continents

Front 15

Panthalassa

Back 15

Giant ocean surrounding Pangaea

Front 16

Plate tectonics

Back 16

Theorythat the lithosphere is made up of plates that float on the asthenosphere and that the plates possibly are moved by convection currents

Front 17

rift valley

Back 17

steep, narrow valley formed as lithospheric plate seperate

Front 18

seafloor spreading

Back 18

Movement of the oceanfloor away from either side of a mid-ocean ridge

Front 19

subduction zone

Back 19

Region where one lithospheric plat moves under another

Front 20

terrane

Back 20

piece of land with a geologic history distinct from that of the surrounding land

Front 21

theory of supect terranes

Back 21

Theory that continents are a patchwork of pieces of land that have individual geologic histories

Front 22

transform fault boundary

Back 22

Boundaryformed where two lithospheric plates slide past each other

Front 23

Anticline

Back 23

Upcurved fold in horizontal rock layers

Front 24

compression

Back 24

stress that squeezes crustal rocks together

Front 25

deformation

Back 25

bending, tilting, and breaking of the earth's crust

Front 26

dome mountain

Back 26

Landform created when molten rock pushes up rock layers on the earth's surface and the layers thenare worn away in places, leaving separate high peaks

Front 27

fault

Back 27

Break in rock along which rocks on either side of the break move

Front 28

fault plane

Back 28

Surface of a fault along which movement of rocks occurs

Front 29

fault-block mountain

Back 29

Mountain formed where faulting breaks the earth's crust into larg blocks and the blocks are uplifted, and tilted

Front 30

folded muntain

Back 30

Landform created when tectonic movements bend and uplift rock layers

Front 31

folding

Back 31

permanent deformation or bending of a rock under stress

Front 32

footwall

Back 32

rock below a fault plane

Front 33

fracture

Back 33

Break in rock along which there is no movement

Front 34

graben

Back 34

long, narrow valley formed by faulting and downward slippage of a crustal block

Front 35

hanging wall

Back 35

rock above a normal fault plane

Front 36

isostasy

Back 36

balancing of the forces pressing up and down on the earth's crust

Front 37

isostatic adjustment

Back 37

up-and-down movements of the earth's crust to reach isostasy

Front 38

Monocline

Back 38

gently dipping bend in horizontal rock layers

Front 39

mountain belt

Back 39

group of lrage mountain systems

Front 40

mountain range

Back 40

group of adjacent mountains with the same general shape and structures

Front 41

mountain system

Back 41

group of adjacent mountain ranges

Front 42

normal fault

Back 42

fault in which the hanging wall moves down relative to the footwall

Front 43

plateau

Back 43

large area of flat-topped rocks high above sea level

Front 44

reverse fault

Back 44

fault in which the hganging wall mvoes up relative to the footwall

Front 45

shearing

Back 45

stress that pushes rocks in opposite horizontal directions

Front 46

strain

Back 46

change in shape and volume of rocks that occurs during stress

Front 47

stress

Back 47

force that causes pressure in rocks of the earth's crust

Front 48

strike-slip fault

Back 48

fault in which the rock on either side of a fault plane slides horizontally

Front 49

syncline

Back 49

downcurved fold in horizontal rock layers

Front 50

tension

Back 50

Stress that pulls rocks apart

Front 51

thrust fault

Back 51

type of reverse fault in which the fault plane is nearly horizontal rather than vertical

Front 52

volcanic mountain

Back 52

mountain formed when molten rock erupts onto the earth's surface

Front 53

aftershock

Back 53

Tremor that follows and is smaller than a major earthquake

Front 54

earthquake

Back 54

vibration of the earth's crust

Front 55

elastic rebound theory

Back 55

theory that rocks that are strained past a certain point will fracture and spring back to their original shape

Front 56

epicenter

Back 56

point on the earth's surface directly above the focus of an earthquake

Front 57

fault zone

Back 57

group of interconnected faults

Front 58

focus

Back 58

area along a fault at which slippage first occurs,initating an earthquake(99); one of two points within an ellipse that determines the shape of the figure

Front 59

intensity

Back 59

amount of damage caused by an earthquake

Front 60

L wave

Back 60

Surface or long wave; the slowest wave generated by and earthquake and the last to be recorded by a seismograph

Front 61

Mercalli scale

Back 61

scale that expresses the intensity of an earthquake with a roman numeral and a description

Front 62

microquake

Back 62

earthquake with a amgnitudeless than 2.5 on the richter scale

Front 63

P wave

Back 63

primary wave; the fastest wave enerated by an earthquake and the first to be recorded by a seismograph

Front 64

Pacific Ring of Fire

Back 64

major earthquake zone tha forms a ring around the Pacific Ocean

Front 65

Richter scale

Back 65

sclae that expressesthe magnitude of and earthquake

Front 66

S wave

Back 66

Secondary wave; a wave generated by an earthquake and the second to be recorded by a seismograph

Front 67

Seismic gap

Back 67

Zone of rock in which a fault is locked and unable to move and in which no major earthquake has occured for at least 30 years

Front 68

seismograph

Back 68

instrument used todetect and record seismic waves

Front 69

tsunami

Back 69

giant ocean wave that oftenoccurs after a major earthquake with an epicenter on the ocean floor

Front 70

aa

Back 70

jagged chunks of lava formed by rapid cooling on the surface of a lava flow (120)

Front 71

caldera

Back 71

large basin-shaped depression formed whenan explosion destroys the upper part of a volcanic cone (124)

Front 72

cinder cone

Back 72

steep-sloped deposit of solid fragments ejected from a volcano (122)

Front 73

composite cone

Back 73

also called (stratovolcano),steep sloped volcanic deposit with alternating layers of hardened lava flows and tephra
(123)

Front 74

crater

Back 74

funnel-shapped pit at the top a volcanic cone(124); bowl-saped depression on the surface of a planetary body

Front 75

felsic lava

Back 75

silica-rich lava (120)

Front 76

fissure

Back 76

crack in a rock surface trough which lava flows
(119)

Front 77

hot spot

Back 77

area of volcanism within a lithospheric plate (119)

Front 78

lapilli

Back 78

tephra particles between 2mm and 64mm in diameter (121)

Front 79

lava

Back 79

magma that reaches the earth's surface (117)

Front 80

mafic lava

Back 80

dark-colored lave rich in magnesium and iron (120)

Front 81

magma

Back 81

liquid rock produced deep inside the earth (117)

Front 82

pahoehoe

Back 82

solidified mafic lava with a wrinkled surface (120)

Front 83

pillow lava

Back 83

lava that flows outof fissures on the ocean floor and cools rapidly in rounded shapes (120)

Front 84

pyroclastic material

Back 84

also called tephra, all of the rock fragments ejectedfrom a volcano (121)

Front 85

shield cone

Back 85

volcanic deposit of hardened lava with a broad base and gentle slopes (122)

Front 86

stratovolcano

Back 86

also called ( composite cone), steep-sloped volcanic deposit with alternating layers of hardened lava flows and tepphra (123)

Front 87

tephra

Back 87

also called (pyroclastic material), all the rock fragments ejected from a volcano (121)

Front 88

vent

Back 88

opening through which molten rock flows onto the earth's surface (117)

Front 89

volcanic ash

Back 89

tephra particles between 0.25mm and 2mm in diameter (121)

Front 90

volcanic block

Back 90

the largest tephra, fromed from slid rock blasted from a fissure (122)

Front 91

volcanic bomb

Back 91

large, spindle-shaped cloth of lava thrown out of a volcano (122)

Front 92

volcanic dust

Back 92

tephra particles less than 0.25mm in diamter (121)

Front 93

volcanism

Back 93

any activity that includes the movement of magma toward or onto the earth's surface (117)

Front 94

volcano

Back 94

lava and tephra built up on the earth's surface around a vent (117)