Earth Science 2

Front 1

Tsunami

Back 1

a large wave along the sea surface triggered by an earthquake or large submarine slump.

Front 2

epicenter

Back 2

center of an earthquake

Front 3

focus(hypocenter)

Back 3

the location where a fault slips during an earthquake

Front 4

stress

Back 4

the push, pull, or shear that something feels when subjected to a force

Front 5

strain

Back 5

the change in shape of an object in response to deformation

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fault

Back 6

a fracture on which one body of rock slides past another

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joint (fracture)

Back 7

naturally formed crack(s) in rocks

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graben

Back 8

a down-dropped crustal block bounded on either side by a normal fault dipping towards the basin

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horst

Back 9

the high block between two grabens

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fault scarp

Back 10

a small step on the ground surface where one side of a fault has moved vertically with respect to the other

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elastic deformation

Back 11

a change in shape that disappears when the stress is removed.

Front 12

plastic deformation

Back 12

process where mineral grains behave like plastic; when compressed or sheared, become flattened or elongate without cracking.

Front 13

brittle deformation

Back 13

the cracking and fracturing of a material subjected to stress.

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anticline

Back 14

a fold with an arch-like shape in which the limbs dip away from the hinge

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syncline

Back 15

a trough-shaped fold whose limbs dip toward the hinge

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basin

Back 16

a fold or depression shaped like a right-side up bowl

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dome

Back 17

folded or arched layers with the shape of an overturned bowl

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plunging fold

Back 18

a fold with a tilted hinge

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monocline

Back 19

a fold in the land surface whose shape resembles that of a carpet draped over a stair step.

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craton

Back 20

a long-lived block of durable continental crust commonly found in the stable interior of a continent.

Front 21

cordillera

Back 21

extensive chain of mountains

Front 22

epeirogeny

Back 22

an event of epeirogenic movement; usually used in reference to the formation of broad mid-continent domes and basins

Front 23

accretion

Back 23

the gradual accumulation of additional layers or matter

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normal fault

Back 24

a fault in which the hanging-wall block moves down the slope of the fault

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reverse fault

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a steeply dipping fault on which the hanging-wall block slides up

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thrust fault

Back 26

a gently dipping reverse fault; the hanging wall block moves up the slope of the fault

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strike-slip fault

Back 27

a fault in which one block slides horizontally past another, so there is no relative vertical motion.

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primary wave

Back 28

(compressional wave) fastest, travels through solids, liquids, gases; travels same direction as the wave propagates.

Front 29

secondary wave

Back 29

shear waves; slower than p wave; only travel through solids; move up and down at right angles according to direction the wave propagates

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surface wave

Back 30

seismic waves that travel along earth's surface

Front 31

richter scale

Back 31

a scale that records an earthquake on the basis of the greatest amplitude felt by a seismogram.

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moment magnitude scale

Back 32

more accurate, accounts for amount and length of rupture on fault and strength of rocks involved.

Front 33

modified mercali scale

Back 33

an earthquake characterization scale based on the amount of damage that the earthquake causes

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EQ intensity

Back 34

based on by mercali intensity scale; how much damage, and what people feel.

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wadati benioff zone

Back 35

a sloping band of seismicity defined by intermediate and deep focus earthquakes that occur in the down going slab of a convergent plate boundry

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liquefaction

Back 36

the process by which wet sediment becomes a slurry; may be triggered by earthquake vibrations

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lateral continuity

Back 37

sediments generally accumulate in continuous sheets within a given region.

Front 38

crosscutting relationships

Back 38

if one geologic feature cuts across another another the feature that has been cut is older.

Front 39

superposition

Back 39

in a sequence of sedimentary rock layers, each layer must be younger than the one below, for a layer of sediment cannot not accumulate unless there is a substrate on which it can collect.

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original horizonality

Back 40

sediments of earth settle out of a fluid in a gravitational field. typically the surfaces are fairly horizontal.

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principle of inclusions

Back 41

if a rock contains fragments of another rock, the fragments must be older than the rock containing them

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unconformities

Back 42

a boundary between two different rock sequences representing an interval of time during which new strata were not deposited and or were eroded

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fossil

Back 43

the remnant or race of an ancient living organism that has been preserved in rock or sediment

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index fossil

Back 44

fossils used to identify and define geologic periods.

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rock correlation

Back 45

blah

Front 46

contact

Back 46

the boundary surface between two rock bodies

Front 47

stratigraphy

Back 47

the study of the record of earth history preserved in strata (pavement- or several beds together)

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comfortable contact

Back 48

i

Front 49

geologic cross section

Back 49

duuh

Front 50

half-life

Back 50

the time it takes for half of a group of radioactive element's isotopes to decay

Front 51

blocking temperature

Back 51

the temp below which isotopes in a mineral are no longer free to move, so the radiometric clock starts

Front 52

radiometric dating

Back 52

the science of dating geologic events in years by measuring the ratio of parent radioactive atoms to daughter product atoms

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radioactive decay

Back 53

the process by which a radioactive atom undergoes fission or releases particles, thereby being transformed into a new element

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geologic time scale

Back 54

a scale that describes the intervals of geologic time

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uniformitarianism

Back 55

oii

Front 56

mass movement

Back 56

gravitationally caused downslope transport of rock, regolith, snow, or ice

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talus

Back 57

a sloping apron of fallen rock along the base of a cliff

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slumps

Back 58

masses of rock/regolith

Front 59

rotational slides (slumps)

Back 59

1wq

Front 60

transitional slides

Back 60

y

Front 61

mudflow

Back 61

downslope movement of mud at slow to moderate speed

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debris flow

Back 62

downslope movement of mud mixed with larger rock fragements

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lahar

Back 63

a thick slurry formed when volcanic ash and debris mix with water, either in rivers or from rain or melting snow and ice on the flank of a volcano

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sinkholes

Back 64

a circular depression in the land that forms when an underground cavern collapses

Front 65

subsidence

Back 65

the vertical sinking of the earth's surface in a region, relative to a reference plane

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drainage basin

Back 66

an array of interconnecting streams that together drain an area.

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meander

Back 67

a snake-like curve along a stream's course

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infiltarion

Back 68

process of seeping down into

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braided stream

Back 69

a sediment choked stream consisting of entwined subchannels

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meandering stream

Back 70

a reach of stream containing many meanders

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delta

Back 71

a wedge of sediment formed at a river mouth when the running water of the stream enters standing water, the current slows, the stream loses competence, and sediment settles out

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alluvial fan

Back 72

a gently sloping apron of sediment dropped by an ephemeral stream at the base of a mountain in arid or semiarid regions

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cut bank

Back 73

the outside bank of the channel wall of a meander, which is continually undergoing erosion.

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point bar

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a wedge shaped deposit of sediment on the inside bank of a meander

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hydrologic cycle

Back 75

the continual passage of water from reservoir to reservoir in the earth system