Earth & Space Science

earth science

the study of Earth and its natural processes

astronomy

the study of space, stars, planets, and other celestial objects

geology

the study of Earth’s rocks, structure, and history

meteorology

the study of weather and the atmosphere

oceanography

the study of oceans and their physical and chemical properties

paleontology

the study of ancient life through fossils

seismology

the study of earthquakes and seismic waves

climatology

the study of climate and long-term weather patterns

crust

the thin, solid outermost layer of Earth

mantle

the thick layer of hot, mostly solid rock beneath the crust

outer core

the liquid layer of iron and nickel surrounding the inner core

inner core

the solid center of Earth, made mostly of iron and nickel

lithosphere

Earth’s rigid outer layer, made of the crust and uppermost mantle

asthenosphere

a softer, slowly flowing region of the upper mantle beneath the lithosphere

atmosphere

the layer of gases surrounding Earth

geosphere

the solid parts of Earth, including rocks, soil, and the interior

magnetic field

the invisible region of magnetic influence around Earth, generated mainly by its liquid outer core

plate tectonics

the theory that Earth’s lithosphere is divided into moving plates

tectonic plates

large pieces of Earth’s lithosphere that move slowly

continental drift

the idea that continents have moved over Earth’s surface over time

pangaea

a supercontinent that once contained nearly all Earth’s landmasses

convergent boundary

where two tectonic plates move toward each other

divergent boundary

where two techtonic plates move apart

transform boundary

where two techtonic plates slide past each other

subduction

when one tectonic plate sinks beneath another

fault

a fracture in Earth’s crust where rocks have moved

earthquake

sudden shaking of Earth caused by the release of energy along a fault

focus (hypocenter)

the underground location where an earthquke begins

epicenter

the point on Earth’s surface directly above an earthquake’s focus

seismic waves

energy waves tha travel through Earth during an earthquake

seismograph

an instrument that records earthquake vibrations

magnitude

a measure of the size of an earthquake

volcano

an opening in Earth’s crust where lava, ash, and gases escape

magma

molten rock beneath Earth’s surface

lava

molten rock that reaches Earth’s surface

ring of fire

a region around the Pacific Ocean with many earthquakes and volcanoes

tsunami

a series of large ocean waves caused by underwater earthquakes or landslides

mineral

a naturally occurring, inorganic solid with a definite chemical composition and crystal structure

rock

a naturally occurring solid made of one or more minerals or other geological materials

igneous rock

rock formed when magma or lava cools and hardens

sedimentary rock

a rock formed when accumulated sediments or chemical and biological deposits

metamorphic rock

rock changed by heat, pressure, or fluids without fully melting

rock cycle

the process by which rocks change from one type to another

intrusive igneous rock

the rock formed when magma cools beneath Earth’s surface

extrusive igneous rock

rock formed when lava cools at Earth’s surface

sediment

small particles of rock, minerals, or organic material

compaction

the process of pressing sediments together

cementation

the process of minerals binding sediment particles together

fossil

preserved remains, traces, or evidence of ancient life

mohs hardness scale

a scale from 1-10 measuring a mineral’s resistance to scratching

streak

the color of a mineral in powdered form

luster

the way a mineral reflects light

cleavage

the tendency of a mineral to break along flat surfaces

fracture

the way a mineral breaks when it does not split along cleavage planes

weathering

the breaking down of rocks into smaller pieces

mechanical weathering

breaking rocks apart without changing their chemical composition

chemical weathering

breaking down or changingg rocks through chemical reactions

erosion

the movement of soil and rock by water, wind, ice or gravity

deposition

the dropping or settling of transported sediments

glacier

a large mass of ice that slowly moves across land

valley

a low area of land between hills or mountains

plateau

a large area of elevated, relatively flat land

plain

a broad area of relatively flat or gently rolling land

delta

an area of sediment deposited where a river enters a body of water

canyon

a deep valley with steep sides, often carved by a river

topography

the shape and physical features of Earth’s surface

topographic map

a map that shows elevations and landforms using contour lines

contour line

a line connecting points of equal elevation

soil

a mixture of minerals, organic matter, water, air, and living organisms

troposphere

the lowest atmospheric layer where most weather occurs

stratosphere

the atmospheric layer containing most of the ozone layer

mesosphere

the atmospheric layer where most meteors burn up

thermosphere

a very thin, hot atmospheric layer where many auroras occur

exosphere

the outermost atmospheric layer, gradually merging into space

ozone layer

a region of the stratosphere that absorbs much of the Sun's harmful ultraviolet radiation

weather

short-term atmospheric conditions in a particular location

climate

the long-term average pattern of weather in a region

temperature

a measure of how hot or cold something is

air pressure

the force exerted by the weight of air

humidity

the amount of water vapor in the air

relative humidity

the percentage of water vapor in the air compared with the maximum possible at that temperature

wind

air moving from areas of higher pressure toward lower pressure

air mass

a large body of air with similar temperature and moisture characteristics

weather front

the boundary between two different air masses

cold front

when colder air advances and pushes warmer air upward

warm front

when warmer air advances over a colder air mass

high-pressure system

an area of relatively high air pressure, often associated with clear weather

low-pressure system

an area of relatively low air pressure, often associated with clouds and storms

barometer

an instrument used to measure air pressure

thermometer

an instrument used to measure temperature

anemometer

an instrument used to measure wind speed

hygrometer

an instrument used to measure humidity

rain guage

an instrument used to measure rainfall

cumulus clouds

puffy clouds that often form in fair weather

stratus clouds

low, layered clouds that may bring overcast skies or light precipitation

cirrus clouds

thin, wispy clouds found high in the atmosphere

cumuloniumbus clouds

tall storm clouds associated with thunderstorms and heavy rain

greenhouse effect

the process by which gases in the atmosphere trap heat and warm Earth

coriolis effect

the apparent deflection of moving air and water caused by Earth's rotation

water cycle

the continuous movement of water between Earth's surface and atmosphere