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Earth Science 9th Grade Glossary > Terms > Flashcards

Terms Flashcards

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1
Q

abrasion

A

the process of particles rubbing against each

other, wearing down the sharp edges into smaller pieces.

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2
Q

absolute magnitude

A

how bright a star appears from 32.6

light years away.

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3
Q

absolute zero

A

temperature at which all molecular motion

ceases (0°K, −273.15°C, or −459.67°F).

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4
Q

acid test

A

tests a mineral or rock for calcite or calcium in its

composition.

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5
Q

active continental margin

A

plate boundary where

mountains are formed.

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6
Q

active volcano

A

volcano that has erupted in recent history

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7
Q

advected fog

A

fog caused by air moving from one region to

another region with a different surface temperature.

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8
Q

advection

A

movement of air from one area to another,

creating unusually warm or cold conditions.

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9
Q

air mass

A

large mass of air at the surface of the Earth with
similar characteristics of temperature and humidity
throughout the mass.

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10
Q

albedo

A

reflection of sunlight.

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11
Q

altitude

A

angle of a celestial object above the horizon.

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12
Q

anemometer

A

instrument used to determine wind speed.

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13
Q

anticline

A

parallel rock layers folded upward, like an arch.

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14
Q

aphelion

A

point in an orbit farthest from the Sun.

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15
Q

apogee

A

point in an orbit farthest from the Earth.

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16
Q

apparent diameter

A

the diameter of an object as it appears

to an observer; changes with distance.

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17
Q

apparent magnitude

A

how bright a star appears to

someone on Earth.

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18
Q

arid

A

climates that are extremely dry, with low precipitation

and high evapotranspiration.

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19
Q

asteroid belt

A

the orbiting band of rocks between Mars and

Jupiter.

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20
Q

asthenosphere

A

the outer layer of the Earth’s mantle, which
has a plastic-like composition; site of convection currents
that move the plates on the surface.

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21
Q

astronomical unit

A

measurement used in the solar system,
the average distance from the Earth to the Sun
(150,000,000 km or 93,000,000 mi).

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22
Q

atmosphere

A

the gas layer surrounding the Earth.

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23
Q

atoll

A

ring of coral reefs surrounding a sunken island.

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24
Q

aurora

A

light created in the sky by the interference of

charged solar particles with the magnetic field of the Earth.

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25
Q

autumnal equinox

A

September 23, when the vertical ray of
the Sun is at the Equator; the entire Earth has 12 hours of
day and 12 hours of night.

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26
Q

azimuth

A

direction along the horizon when looking for an

object in the sky.

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27
Q

big bang hypothesis

A

says that origin of the universe was
when all matter was collected together and exploded, about
15 billion years ago

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28
Q

blue shift

A 
apparent shortening of starlight as it moves
toward you (Doppler).
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29
Q

buoyant

A

describes a property that causes materials to

appear to float in or on a fluid.

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30
Q

caldera

A

extinct volcano that has a collapsed cone.

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31
Q

capillary

A

water that works its way upward in the ground

through adhesion to rock particles and cohesion to itself.

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32
Q

carbonates

A

the family of minerals composed of carbon and

oxygen.

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33
Q

Cephid

A

a star that varies in its light output.

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34
Q

chemical weathering

A

the breaking down of rock material

by chemical means, forming a new substance.

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35
Q

chromosphere

A

reddish layer of the Sun that is hydrogen

burning.

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36
Q

cinder cone

A

steep cone of a volcano formed from ash and

loose rock.

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37
Q

cirrus

A

very high clouds formed by ice crystals; look like

feathers; usually associated with fair weather.

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38
Q

clastic

A

pieces of rock

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39
Q

cleavage

A

the way a mineral splits or breaks along weak

bonds in planes.

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40
Q

climate

A

the overall temperature, precipitation, and weather

conditions for an area.

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41
Q

cold front

A

the leading edge of a cold air mass.

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42
Q

color (as relates to ID)

A

an easy test in the identification of minerals, but not

always reliable

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43
Q

column

A

pillar of rock formed when a stalactite and

stalagmite merge.

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44
Q

comet

A

a mass of frozen gases, ice, and rock that orbits the

Sun.

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45
Q

composite volcano

A

a volcano consisting of a cone of

alternating layers of solidified lava and rock particles.

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46
Q

compound

A

a molecule made up of two or more elements.

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47
Q

condensation

A

the process of a substance changing states

from gas to liquid.

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48
Q

conduction

A

transfer of energy through solids by direct

contact.

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49
Q

constellation

A

a group of stars that appears to be in a

pattern.

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50
Q

contact metamorphism

A

the process of changing rocks into

metamorphic rocks by nearby magma.

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51
Q

continental glacier

A

a thick sheet of ice covering a mass of
land all year round, moving outward from the thickest part;
found only in Greenland and Antarctica.

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52
Q

continental rise

A

area which connects the continental slope

to the ocean floor

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53
Q

continental shelf

A

ocean bottom along the coasts with a low

gradient.

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54
Q

continental slope

A

ocean bottom that connects the

continental shelf to the deep ocean floor

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55
Q

contour farming

A

planting crops along contour lines on a hill

to help prevent soil erosion.

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56
Q

contour line

A

line connecting points of equal elevation.

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57
Q

convection

A

transfer of energy in fluids; can create currents

by density differences.

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58
Q

converging plate boundary

A

region where plates move

toward each other.

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59
Q

coordinate system

A

rectangular grid system for plotting

points.

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60
Q

Nicolas Copernicus

A

astronomer who developed the

heliocentric model.

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61
Q

corona

A

outermost layer surrounding the Sun.

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62
Q

crater

A

impact mark left on a planet or moon by a collision

with a another object

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63
Q

craton

A

core rock base of a continent.

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64
Q

creep

A

slow movement of rocks and sediments down a

hillside.

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65
Q

crust

A

the thin, outer layer of the solid part of the Earth.

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66
Q

crystal shape

A

the arrangement of molecules in a mineral.

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67
Q

cumulonimbus

A

cumulus cloud that builds vertically; usually

associated with a cold front and thunderstorms.

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68
Q

cumulus

A

puffy, cotton-like clouds formed by rising air.

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69
Q

cyclogenesis

A

the process of forming storm systems.

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70
Q

deficit

A

time during the water budget when drought
conditions occur; there is not enough water to supply the
needs of an area.

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71
Q

delta

A

a triangle-shaped area of deposition located at the

mouth of an older river.

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72
Q

density

A

the amount of matter in a given space.

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73
Q

deposition

A

the rare process of a substance changing states

from gas directly to a solid.

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74
Q

derived unit

A

unit that is a combination of basic units.

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75
Q

dew point

A

temperature at which water vapor condenses

into liquid water.

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76
Q

discharge

A

the amount of water in a river or stream that

passes a certain point in a given amount of time.

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77
Q

diverging plate boundary

A

region where plates move

apart.

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78
Q

doldrums

A

region along the Equator where the weather

conditions are fairly consistent.

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79
Q

dormant volcano

A

volcano that has not erupted during

recorded history.

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80
Q

drainage basin

A

the area around a stream that could drain

into the stream.

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81
Q

drainage divide

A

the outer edge between drainage basins

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82
Q

drift

A

small particles carried away from larger rocks by

glacial meltwater.

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83
Q

drizzle

A

liquid precipitation that is less than .02 cm in

diameter.

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84
Q

dry adiabatic lapse rate

A

e rate at which dry air cools as it

rises upward.

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85
Q

dry bulb temperature

A

temperature of the air.

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86
Q

dynamic equillibrium

A

a system that fluctuates, but overall

is in balance.

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87
Q

El Nino, La Nina

A

long-term weather patterns associated
with changing global winds and ocean temperatures in the
Pacific Ocean.

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88
Q

electromagnetic spectrum

A

diagram that breaks down

energy by wavelength.

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89
Q

epicenter

A

location on the Earth’s surface directly above the

focus of an earthquake.

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90
Q

epicycle

A

small circle made by a planet’s orbit in the

geocentric model.

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91
Q

equillibrium

A

a system that is in balance.

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92
Q

erosion

A

the transportation of weathered materials.

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93
Q

erratic

A

a large rock that is deposited by a glacier.

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94
Q

explosive eruption

A

volcanic activity containing thick lava

and more gases under pressure; creates steeper cones

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95
Q

extrusive

A

rock that forms on the Earth’s surface.

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96
Q

eye

A

center of circulation in a hurricane, where the conditions

are calm.

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97
Q

eye wall

A

area surrounding the eye of a hurricane, where

winds are most intense.

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98
Q

fault

A

a crack or break in a rock.

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99
Q

fault plane

A

the surface that rocks move along when plates

shift.

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100
Q

fault block mountain

A

mountain range formed when

sections of sedimentary rocks are tilted upward in sections

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101
Q

felsic

A

magma that is aluminum or silica based, lighter in

color, and less dense than mafic magma.

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102
Q

fetch

A

length of open ocean for wind to create waves.

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103
Q

field

A

an area where there is a measurable amount of a

specific value at every point

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104
Q

flood plain

A

the area along the banks of a meandering river

that are prone to flooding at various times.

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105
Q

focus

A

exact site of the origin of an earthquake, below the

epicenter.

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106
Q

folded mountains

A

mountain range formed by the collision
of continental plates, causing the rock layers to be
crumpled.

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107
Q

foliated texture

A

layered mineral crystals in a metamorphic

rock.

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108
Q

fossil

A

evidence that life was present, preserved in a rock.

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109
Q

fracture

A

the uneven breaking or cracking of a mineral.

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110
Q

frost

A

the boundary between two air masses.

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111
Q

frost point

A

dew point temperature, below 0°C.

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112
Q

Fujita scale

A

scale for measuring the intensity of a tornado

from F0 to F5.

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113
Q

Galileo

A

scientist whose observations supported the

Copernican model.

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114
Q

geocentric

A

a model in which Earth is at the center of the

universe.

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115
Q

geyser

A

groundwater deep in the Earth that turns to steam
and is forced to the surface when enough pressure is
generated.

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116
Q

granule

A

one of the individual cells that make up the

photosphere of the sun.

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117
Q

graphical model

A

a graph showing relationships.

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118
Q

greenhouse effect

A

incoming (shortwave) energy is
reradiated as heat energy (longwave) and trapped by the
greenhouse gases in the atmosphere; causes global
warming.

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119
Q

greenhouse gas

A

a gas produced from burn fossil fuels,
which hold and trap heat energy; carbon dioxide is an
example.

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120
Q

ground fog

A

fog formed by radiational cooling.

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121
Q

guyot

A

flat-topped seamount, eroded by ocean waves while

exposed.

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122
Q

hail

A

layers of ice formed in a large thunderstorm cloud that

fall to Earth.

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123
Q

half life

A

the amount of time it takes a radioactive element

to decay into half of its original mass.

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124
Q

heliocentric

A

sun-centered model of the solar system.

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125
Q

Horse Latitude

A

area of little surface winds and high

pressure along 30° N latitude.

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126
Q

hot spot

A

weak or thin area in a plate that allows magma to

rise up and reach the surface.

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127
Q

hot spring

A

groundwater heated by magma rising to the

surface through an opening in the ground.

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128
Q

hurricane

A

low-pressure system with sustained winds of 74

mph or greater.

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129
Q

hydrosphere

A

the water layer of the Earth.

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130
Q

hygrometer

A

an instrument used to measure humidity; can

be made from hair.

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131
Q

igneous

A

rock formed when molten rock cools.

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132
Q

impermeable

A

rock that water cannot sink into or through.

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133
Q

index fossil

A

a fossil of an organism that occurred for a
short amount of time and over a widespread area; used to
connect rock layers over long distances.

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134
Q

inference

A

an educated guess based on collected data

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135
Q

infiltration

A

water sinking into the ground.

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136
Q

inner core

A

the solid center of the Earth, composed of iron

and nickel.

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137
Q

insolation

A

a combination of the words incoming solar

radiation.

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138
Q

instrument

A

tool used to extend your senses and gather

data.

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139
Q

International Date Line

A

the longitude line measuring 180°

where the day changes.

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140
Q

Intertropical Convergence Zone

A

area along the Equator
where trade winds from the Northern and Southern
hemispheres meet, forming thunderstorms.

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141
Q

intrusion

A

magma that crosses through other rock layers,

cooling and hardening before reaching the surface.

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142
Q

intrusive

A

rock that forms below the Earth’s surface

plutonic

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143
Q

inversion

A

an atmospheric condition where warm air is on

top of cold air.

144
Q

isobar

A

line connecting areas of equal pressure on a map.

145
Q

isoline

A

line that connects equal values.

146
Q

isosurface

A

three-dimensional diagram showing surfaces

connecting equal values.

147
Q

isotherm

A

line connecting areas of equal temperature on a

map.

148
Q

isotopes

A

two elements that have the same atomic number

but different atomic masses.

149
Q

jet stream

A

band of fast-moving air in the upper

troposphere.

150
Q

Jovian Planet

A 
outer planet (Jupiter, Saturn, Uranus, and
Neptune) consisting of a gaseous surface.
151
Q

Kepler

A

astronomer who developed three laws
of planetary motion: planets move in elliptical orbits; planets
sweep out equal area in equal time; the period of revolution
is proportional to the distance to the Sun.

152
Q

kettle

A

a steep-sided pond created by a glacier when a block

of ice is left behind as the glacier retreats.

153
Q

key bed

A

a layer in the rock record showing an event that
occurred quickly and over a widespread area; is used like an
index fossil.

154
Q

land breeze

A

local wind that forms at night along a beach
due to uneven cooling rates of land and water, wind moves
from land to water.

155
Q

lateral moraine

A

the pile of rocks that accumulate along the

edges of a glacier.

156
Q

latitude

A

coordinate lines for locating a position on Earth
that run east and west and are parallel to each other,
running from 0° to 90° (angle from the equator).

157
Q

lava

A

liquid rock on the surface of the Earth.

158
Q

leeward

A

the side opposite from the prevailing wind

direction.

159
Q

lifting condensation level

A

formula used to find the height

at which clouds can form.

160
Q

light year

A

the distance that light travels in one year, about

9.5 trillion kilometers.

161
Q

lightning

A

electricity generated by a thunderstorm.

162
Q

line graph

A

points plotted on a coordinate system and

connected with a line.

163
Q

lithosphere

A

the rock layer on the outer edge of the Earth.

164
Q

local noon

A

occurs when the Sun is at its highest point for

the day.

165
Q

longitude

A

coordinate lines for locating position on Earth
that run north and south through the poles, are farthest
apart at the Equator, run from 0° to 180°, are equal in
length, and are measured from the Prime Meridian.

166
Q

longshore current

A

a current moving parallel to the coast.

167
Q

low pressure center

A

counterclockwise circulation center,

formed along a stationary front in the Northern Hemisphere.

168
Q

luminosity

A

actual brightness of a star.

169
Q

lunar eclipse

A

the Moon goes out of view as it moves into

the Earth’s shadow; occurs during the Full Moon phase.

170
Q

luster

A

the way a mineral shines in reflected light.

171
Q

L wave

A

longitudinal wave created by the P-wave and Swaves of an earthquake at the surface of the Earth; these
are the slowest and move outward like ripples on a pond.

172
Q

mafic

A

magma that is iron or magnesium-based, darker in

color, and more dense than felsic magma.

173
Q

magma

A

liquid rock below the Earth’s surface.

174
Q

magnetic declination

A

the number of degrees that a
compass needle is pulled away from True North to point
toward Magnetic North.

175
Q

Magnetic North

A

the area near Hudson Bay, Canada, where
the Earth’s magnetic field is strongest in the Northern
Hemisphere (location changes over time).

176
Q

main sequence star

A

star that falls into broad band along

the H-R diagram.

177
Q

mantle

A

the layer below the crust; about 2,900 km thick;

contains rocks rich in iron, magnesium, and silicon

178
Q

maria

A

large, flat areas on the Moon.

179
Q

Marianas Trench

A

deepest trench in the world; lies off the

coast of Japan.

180
Q

mathematical model

A

an equation representing an idea.

181
Q

matter

A

anything that has mass and takes up space.

182
Q

mechanical model

A

a physical model with moving parts.

183
Q

mechanical weathering

A

the physical breaking down of
rock, changing only its size (smaller); examples are ice
wedging, plant action, and pressure unloading.

184
Q

medial moraine

A

the moraine created when two glaciers

meet and their lateral moraines merge.

185
Q

mental model

A

an idea or model that exists in your mind.

186
Q

mercalli scale

A

scale for measuring earthquakes based on

obsevations.

187
Q

meridiean

A

line of longitude

188
Q

mesopause

A

region between the mesosphere and the

thermosphere.

189
Q

mesosphere

A

part of the atmosphere between the
stratosphere and the thermosphere; temperatures decrease
with altitude.

190
Q

metamorphic

A

existing rock that undergoes extreme heat or

pressure and is recrystallized.

191
Q

meteor

A

a meteoroid that enters the Earth’s atmosphere;

also known as a shooting star.

192
Q

meteorite

A

a meteor that reaches the surface of the Earth.

193
Q

meteoroid

A

a rock fragment orbiting in the solar system.

194
Q

mid latitude low

A

low-pressure system that forms along a

stationary front.

195
Q

mid ocean ridge

A

area between two diverging plates, where
magma reaches the surface and causes an area of increased
elevation and new crust along the ocean floor.

196
Q

Milankovich period

A

long term climate changes due the

wobble of the Earth’s revolution around the Sun.

197
Q

Milky Way galaxy

A

the spiral galaxy that includes our solar

system near its outer edge.

198
Q

model

A

a scale representation of another object or idea

199
Q

Moh’s Hardness Scale

A

a relative scale ranging from 1 to
10, measuring whether a mineral can scratch another
mineral.

200
Q

moist adiabatic lapse rate

A

rate at which humid air cools

as it rises upward.

201
Q

monsoon

A

seasonal wind pattern changes that cause rainy

and dry seasons.

202
Q

moraine

A

large area of deposition left behind from the

advance of a glacier.

203
Q

natural selection

A

theory by Charles Darwin which states
that organisms best fit for their environment will survive and
pass along these traits.

204
Q

neap tide

A

tide with the smallest tidal range; during both

quarter phases.

205
Q

nebula

A

a cloud of gas and dust in space.

206
Q

Newton

A

developed the universal law of gravity.

207
Q

nonrenewable resource

A

natural resources that cannot be

replenished for millions of years, if at all.

208
Q

normal fault

A

fault that occurs when rocks are pulled apart,

causing one side to move downward.

209
Q

oblate spheroid

A

the shape of the Earth; not a perfect
sphere, but flatter at the poles and slightly bulging at the
Equator.

210
Q

observation

A

data that is collected through your senses.

211
Q

occluded front

A

front that forms when a cold front catches

up to a warm front.

212
Q

orogeny

A

a mountain-building period or event.

213
Q

outer core

A

the iron- and nickel-rich liquid layer near the

center of the Earth.

214
Q

outgassing

A

gases that escape to the atmosphere during

volcanic eruptions.

215
Q

outwash plain

A

sandy area downstream from a moraine

created by drift particles and meltwater from a glacier.

216
Q

overriding plate

A

crustal plate which collides with a more

dense plate and moves above the plate.

217
Q

overturning

A

rock layers that are flipped upside-down

during the mountain-building process.

218
Q

parallax

A

the apparent change in the position of stars due

to Earth’s revolution.

219
Q

parallels

A

lines that never meet, such as latitude.

220
Q

passive continental margin

A

area along the coast where

sediments are deposited.

221
Q

pause

A

a region separating two layers of the atmosphere.

222
Q

penumbra

A

the lighter, gray area of a shadow.

223
Q

percent error

A

formula used to find the inaccuracy of a

measurement.

224
Q

perigee

A

position in an orbit that is closest to the Earth.

225
Q

perihelion

A

point in an orbit that is closest to the Sun

226
Q

permeability

A

the rate at which water sinks into the ground.

227
Q

photosphere

A

outer layer of the Sun.

228
Q

physical model

A

l a representation of an object that you can

hold.

229
Q

phytoplankton

A

microscopic plants floating freely in the

ocean.

230
Q

plutonic

A

rock that forms below the Earth’s surface

intrusive

231
Q

Polaris

A

the North Star, located in the Little Dipper

constellation.

232
Q

pollution

A

a substance that harms living organisms or the

environment.

233
Q

porosity

A

the percentage of open space between soil

particles and rocks.

234
Q

porphyritic texture

A

rocks that have different-sized

crystals, created at different times.

235
Q

prevailing westerlies

A

planetary winds between 30° and
60° latitude; they guide weather systems for the United
States (from SW to NE).

236
Q

Prime Meridian

A

0° longitude line, running though

Greenwich, England.

237
Q

profille

A

side view of land on a topographic map.

238
Q

psychrometer

A

an instrument with a dry-bulb thermometer
and a wet-bulb thermometer; used to measure dewpoint
and relative humidity.

239
Q

Ptolemy

A

astronomer who developed the geocentric model.

240
Q

pulsar

A

a star that sends energy out in pulses.

241
Q

punctuated equillibrium

A

theory that organisms just

“appear” on Earth.

242
Q

P Waves

A

primary waves generated by an earthquake; these
compression waves are the fastest and travel through solids,
liquids, and gases.

243
Q

radiation

A

transfer of energy through a vacuum; the way in

which the Sun supplies the Earth with energy.

244
Q

radioactive element

A

an atom that emits gamma rays,
alpha particles, and beta particles; can be used to determine
age.

245
Q

radiosonde

A

weather balloon that carries instruments to

record data and transmit readings to a base unit.

246
Q

rain

A

liquid precipitation larger than .02 cm in diameter.

247
Q

recharge

A

e the period of time during the water-budget cycle

when the water in the ground is being replenished.

248
Q

red giant

A

stage of the life cycle of a star in which it expands

and cools.

249
Q

Red Shift

A 
apparent lengthening of starlight as it moves away
from you (Doppler).
250
Q

regionally metamorphic

A

rock that undergoes intense heat

and pressure over large areas.

251
Q

relative humidity

A

a measure of how much water is in the
air compared to how much it can hold, given as a
percentage.

252
Q

renewable resources

A

energy sources or other natural

resources that are replenished shortly after being used.

253
Q

retrograde motion

A

the apparent backward movement of a

celestial object.

254
Q

reverse fault

A

t rocks that crack and are thrust upward,

forming an overhang; caused by the compression of rocks.

255
Q

Richter scale

A

e scale for measuring earthquakes based on

energy released.

256
Q

rift erruption

A

lava flows in long, narrow cracks of the Earth’s

crust

257
Q

rift valley

A

the space between diverging plates.

258
Q

rip current

A

strong surface currents that move like small
rivers perpendicular to the shoreline, caused by water
returning from the beach to the ocean.

259
Q

rock cycle

A

the continuous flow from one type of rock to

another.

260
Q

Saffir-Simpson scale

A

scale for measuring hurricane

intensity, from Category I to Category V.

261
Q

salinity

A

amount of dissolved salts in water.

262
Q

saturated

A 
cannot hold any more water, as in groundwater
or air (humidity).
263
Q

scalar

A

field values that measure magnitude

264
Q

scale

A

the proportion of a model in relation to the original.

265
Q

scientific notation

A

a method of converting very large or
very small numbers into a convenient value using
exponents.

266
Q

sea breeze

A

local wind that develops during the day along a
beach due to uneven heating of land and water; wind moves
from water to land.

267
Q

seamount

A

underwater mountain.

268
Q

sedimentary

A

rock formed from the compaction and

cementation of fragments from other rocks.

269
Q

seismogram

A

paper record graphing earthquake motions,

created by a seismograph.

270
Q

seismograph

A

machine that detects earthquakes.

271
Q

severe thunder storm

A

thunderstorm that has winds in

excess of 50 mph and can produce large hail.

272
Q

shadow zone

A

area of the Earth shielded from earthquake
waves by the outer core (where S-waves are absorbed and
P-waves are refracted).

273
Q

shield cone

A

broad cone of a volcano resulting from smooth

lava flows.

274
Q

silicates

A

group of minerals with silicon and oxygen as a

base.

275
Q

sliding plate boundary

A

region where plates move next to

each other.

276
Q

sling psychrometer

A

a handheld psychrometer than spins

around, used to measure dewpoint and relative humidity.

277
Q

slip face

A

the back side of a sand dune.

278
Q

slump

A

rock material that is moved downhill as a block of

land is uplifted.

279
Q

solar eclipse

A

event in which the view of the Sun is blocked
by the Moon during a New Moon phase, when the Moon’s
shadow reaches the Earth.

280
Q

solar noon

A

the highest point of the Sun on any day.

281
Q

solar prominence

A

flame-like arc extending out from the

Sun.

282
Q

specific gravity

A

the relative density of a mineral, compared

to water.

283
Q

specific humidity

A

a measure of how much water is

actually in the air.

284
Q

spectroscope

A

instrument for separating visible light into

colors.

285
Q

spiral galaxy

A

galaxy with bands of stars that rotate around

the center.

286
Q

spring tide

A

extreme tides during Full and New Moon

phases.

287
Q

stalactite

A

rock icicle forming from the ceiling of a cave.

288
Q

stalagmite

A

rock formation rising up from a cave floor.

289
Q

station model

A

a diagram on a weather map showing

weather data from a specific city at a given time.

290
Q

stationary front

A

initial boundary between two air masses.

291
Q

storm surge

A

bubble of water carried by a hurricane,

causing coastal flooding.

292
Q

stratopause

A

the region between the stratosphere and the

mesosphere.

293
Q

stratosphere

A

the layer of the atmosphere above the

troposphere; temperature increases with altitude.

294
Q

stratus

A

layered, sheet-like clouds, usually associated with

warm fronts and found at lower altitudes.

295
Q

streak

A

the color of the powder left behind when a mineral is

rubbed along an unglazed porcelain tile.

296
Q

striations

A

parallel scratches on the Earth’s surface caused
by rocks dragged by a glacier; the scratches point in the
direction of the glacial movement.

297
Q

strike slip fault

A

a fault where rock plates move horizontally

to each other.

298
Q

subducting plate

A

crustal plate which collides with another

plate and moves under it.

299
Q

sublimation

A

the rare process of a substance changing

states from solid directly to a gas.

300
Q

subsidence

A

land sinks into the sea; opposite of uplifting.

301
Q

summer solstice

A

June 21, when the vertical ray of the Sun
is at the Tropic of Cancer (23.5° N latitude), and is the
longest day of the year in the Northern Hemisphere.

302
Q

sunspot

A

cooler area on the surface of the Sun

303
Q

supercell

A

l thunderstorm with strong updrafts that exist for

hours and can spawn tornadoes.

304
Q

supernova

A

the explosion of a star

305
Q

surplus

A

the period of time when the precipitation exceeds
the needs for an area and the ground is saturated; runoff
occurs, causing flooding conditions.

306
Q

S-waves

A

secondary waves created by an earthquake; these
shearing waves move at right angles to the path of travel
and are stronger than P-waves, but only move through
solids.

307
Q

syncline

A

parallel rock layers folded downward in a valleylike formation.

308
Q

talus

A

a pile of rocks at the bottom of a hill.

309
Q

terminal moraine

A

a moraine created at the end of the

advance of a glacier.

310
Q

terrane

A

large pieces of rock that are moved large distances;

can be from another plate.

311
Q

terrestrial planet

A 
inner planet (Mercury, Venus, Earth, and
Mars) with a rocky surface.
312
Q

thermocline

A

zone in water where the temperature changes

drastically.

313
Q

thermosphere

A

uppermost layer of the atmosphere;

temperatures increase with altitude.

314
Q

thinskinned thrusting

A

thin, horizontal sheets of rock from

the edge of a continent are forced inland.

315
Q

till

A

an unsorted pile of sediment left behind when a glacier

melts.

316
Q

topographic map

A

map that shows elevations above sea

level.

317
Q

tornado

A

narrow, funnel-shaped column of wind created by a

thunderstorm.

318
Q

trace fossil

A

evidence that life existed in the past, such as

footprints and burrows.

319
Q

trade winds

A

planetary winds between 0° and 30° latitude.

320
Q

transform plate boundaries

A

region where plates move next

to each other.

321
Q

transparent

A

light can pass through the substance.

322
Q

trench

A

a deep canyon in the ocean caused by a plate being

subducted under another plate.

323
Q

tropical depression

A

strong low-pressure system formed in

low latitudes.

324
Q

tropical storm

A

low-pressure system with sustained winds

from 39 to 73 mph.

325
Q

tropopause

A

region between the troposphere and the

stratosphere.

326
Q

troposphere

A

lowest level of the atmosphere, where

weather occurs; temperature decreases with altitude.

327
Q

True North

A

geographic North Pole, latitude 90° N.

328
Q

tusnami

A

a large wave created by an underwater earthquake

or landslide.

329
Q

turbidity currents

A

undersea mudslides.

330
Q

umbra

A

the darkest part of a shadow.

331
Q

unconformity

A

a break or gap in the rock record where

layers of rock have been eroded.

332
Q

universal law of gravity

A

formula that measures the force

of gravity; developed by Isaac Newton.

333
Q

updraft

A

wind current moving upward in a cloud.

334
Q

upwelling

A

deep ocean water is pulled to the surface by

currents.

335
Q

urban heat island effect

A

city areas are warmer than
suburbs or rural areas due to less vegetation, more land
coverage and other infrastructure.

336
Q

usage

A

time in the water budget for an area when water is

being used faster than it is being replenished.

337
Q

valley glacier

A

a glacier located on top of a mountain, also
called an alpine glacier, that moves downhill through the
valley.

338
Q

vaporization

A

the process of boiling.

339
Q

varve

A

alternating layers of sediment showing yearly cycles.

340
Q

vector

A

field quantity that measures magnitude and

direction.

341
Q

Vernal equinox

A

March 21, when the vertical ray of the Sun
is at the Equator; the entire Earth has 12 hours of day and
12 hours of night.

342
Q

vertical ray

A

radiational energy from the Sun that strikes the

Earth at a right angle.

343
Q

vesicular texture

A

rock that has gas pockets and air that

was trapped during the rock’s formation.

344
Q

waning

A

part of the lunar cycle in which the Moon is getting

less full and the “left side is lit up” (left side lit).

345
Q

warm front

A

the leading edge of a warm air mass.

346
Q

water table

A

the surface of the water in the zone of

saturation.

347
Q

waxing

A

part of the lunar cycle when the Moon is getting

more full, and the “right side is lit up.”

348
Q

weathering

A

the physical or chemical breaking down of

rocks due to exposure to the atmosphere.

349
Q

wet bulb depression

A

difference between wet-bulb and
dry-bulb temperatures, used to find relative humidity and
dew point temperatures.

350
Q

white dwarf

A

final stage of a star as it collapses onto itself.

351
Q

windward

A

the side facing the wind.

352
Q

Winter solstice

A

December 21, when the vertical ray of the
Sun is at the Tropic of Capricorn (23.5° S latitude), the
shortest day of the year in the Northern Hemisphere.

353
Q

zenith

A

the point directly overhead of an observer.

354
Q

zone of accumulation

A

upper level of a glacier where more

snow falls than melts.

355
Q

zone of aeration

A

area underground above the water table
where the spaces between rocks contain a mixture of air and
water.

356
Q

zone of saturation

A

area underground where the spaces

between rock particles are filled with water.

Earth Science 9th Grade Glossary (1 decks)

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