FOURTH NINE WEEKS VOCABULARY FROM HARCOURT SCIENCE

Air pressure The weight of air.

Anthracite A hard, black rock in the third stage of coal formation

Atmosphere The layer of air that surrounds the earth

Axis An imaginary line that passes through the Earth’s
Center and its North and South Poles

Bitumen The third stage in coal formation. This rock is softer
than Anthracite coal, but is still useable energy .

Climate The average of all weather conditions through all
seasons over a period of time

Core The center of the Earth

Continental Drift The theory of how the continents move

Crust The thin, outer layer of the Earth

Deposition The process of dropping sediment in a new location

Desalinization The process of removing salt from seawater

Earthquake Shaking of the earth due to a sudden release of
energy in the Earth’s crust

Eclipse The passing of one object through the shadow of
another.

El Nino A short term climate change that occurs every two
to ten years.

Erosion The process of moving sediment from one place to another.

Estuary The place where fresh water empties into the ocean

Fault A break or place where pieces of the Earth’s crust move

Fossil Remains or traces of past life found in sedimentary rock

Fossil Fuel A fuel formed from the remains of once living organisms

Galaxy A group of stars, gas and dust

Global Warming The hypothesized rise in Earth’s average temperature from excess carbon dioxide

Greenhouse Effect Process by which the Earth’s atmosphere absorbs heat

Humidity A measure of the amount of water in the air

Landform A physical feature on the Earth’s surface

Light-year The distance light travels in one Earth year; about 9.5 trillion km

Lignite A soft, brown rock, the second stage in coal formation

Local winds Winds dependent on local weather conditions

Magma A hot, soft rock from the Earth’s lower mantle

Magnitude Brightness of stars

Main Sequence A band of stars that includes most stars of average color, size, magnitude and temperature

Mantle The layer of rock beneath the Earth’s crustMass Movement The downhill movement of rock and soil due to Earth’s gravity

Microclimate The climate of a very small area

Natural Gas A gas,methane,usually found with petroleum

Natural Resource Any useful minerals and other materials that people take from the Earth

Nonrenewable Resource A resource that can not be readily replaced once it is used

Orbit The path one body in space takes as it revolves around another body, such as that of the Earth as it revolves around the sun

Pangea A super continent containing all of Earth’s land that existed about 225 million years ago

Photosphere The visible surface of the sun

Plate The rigid blocks of the Earth’s crust and upper mantle rock

Precipitation Any form of water that falls from clouds such as rain or snow

Prevailing winds The global winds that blow constantly from the same direction

Recycling Reusing something again

Renewable resource A resource that can be replaced as it is used

Reusable resource A resource that is renewed by natural cycles and can be used more than once; an inexhaustible resource

Revolve To travel in a closed path around an object such as the Earth does as it moves around the sun

Rotate The spinning of the Earth on its axis

Satellite A natural body like the moon, or an artificial body that orbits another object

Solar Flare A brief burst of energy from the sun’s photosphere

Solar Wind A fast moving stream of particles thrown into space by solar flares

Sonar A device that uses sound waves to determine water depthj

Space Probe A robot vehicle used to explore deep space

Sunspot A dark,cooler spot on the photosphere or surface of the sun

Telescope An instrument that magnifies distant objects

Tide The repeated rise and fall in the level of the ocean caused by the gravitational pull of the moon and to a lesser degree, the sun

Tide Pool A pool of sea water found along the rocky shoreline

Universe Everything that exists-planets,stars,gasses and energy

Volcano A mountain formed by lava and ash

Weathering The process of breaking rock into soil, sand and other tiny pieces

Weight A measure of the pull of gravity on an object