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A Hawaiian term for sharp and pointy basaltic lava flow.


The erosion of rock by being either carried along a stream or sandblasted by wind. The process wears down the rock

abyssal plain

A large, flat area of the deep ocean floor.

acid rain

Acid precipitation which can cause serious environmental damage. It is caused by pollution, especially from the burning of coal, car exhaust, and smoke from factories.


Any wind-related process. Refers to things carried, deposited, or eroded by the wind. Named for the Greek god of the wind.


A mini earthquake that occurs after a large earthquake, sometimes intermittently for several years.

air mass

The weight of air above any point. It decreases as altitude increases.


The percentage of the sun's radiation that is reflected offf a surface. For example: the ________ of snow is very high because its white color is very reflective.

alluvial fan

Fan-shaped deposits of sediment found at the foot of a mountain range brought there by mountain streams on their way from the mountains to the valley below.

alpine glacier

A glacier that forms high in the mountains.


An instrument that measures the speed of wind.


An area of high pressure with winds that rotate clockwise in the Northern Hemisphere and counter-clockwise in the Southern Hemisphere. (opposite of a cyclone)


Two points or regions on opposite sides of the planet from each other. For example, if you were able to dig a hole through the earth from the United States, you would reach the Indian Ocean -- not China -- because the ________ of the United States is a region in the Indian Ocean.


The point in Earth's orbit when the Earth is farthest from the sun.


The point in the moon's orbit where the moon is farthest from the Earth.


An underground rock layer that groundwater cannot enter or pass through.


A rock layer that holds groundwater.

Arctic Circle

Latitude 66.5 degrees N., marking the southern boundary of that portion of the N. Hemisphere that receives a 24 hour period of sunlight once each year - occurs on June 22.

Antarctic Circle

Latitude 66.5 degrees S, marking the northern boundary of that portion of the S. Hemisphere that receives a 24 hour period of sunlight once each year - occurs on December 22.


Dry, often used to describe the land, which is an area that is dry due to limited precipitation.


A Spanish term meaning a dry streambed that fills with water following heavy rains. Similar to a wadi and a wash.

artesian well

A well from which water rises due to underground pressure.


Tiny particles ejected from a volcano during an eruption.


One of the four spheres of the Earth. The layer of gas that surrounds the Earth where weather and climate take place. Often referred to as air. The other three spheres are the biosphere, the hydrosphere, and the lithosphere.


A ring of coral reef that encloses a lagoon.


Colorful lights in the night sky. Known in the Northern Hemisphere as the northern lights.


The rapid fall of snow, ice, or rocks from a mountainside.


An imaginary line that runs from the north pole to the south pole around which the earth turns. It is angled at 23.5 degrees which causes the seasons.


An instrument that measures atmospheric pressure.

barrier island

An island parallel to the shoreline, typically formed by sand deposited by waves.


A body of water formed by a curved indention of a coastal shoreline, larger than a cove and smaller than a gulf.

Beaufort scale

A scale developed by a British admiral to measure wind speed using visual clues. It runs from 0-12 with 0 being calm and 12 being hurricane force winds.


The variety of living things in an area.


One of the four spheres of the earth. The areas of Earth that are home to all living things. The other three spheres are the lithosphere, hydrosphere and atmosphere.


A flat-topped hill with steep sides. Larger than a pinnacle and smaller than a mesa.


A large, circular cavity that remains after the explosion and collapse of a volcano.


The breaking off of large chunks of ice from a glacier or an ice seet, sometimes forming icebergs.


A deep valley with steep sides carved by a river.


Rapids or a waterfall that flows down multiple steps.


A series of rapids, especially those along the Nile River, or of a large river with a single drop.


A system for the measurement of temperature, with 0 degrees the temperature at which water freezes and 100 degrees the temperature at which water boils.

chinook winds

A warm and dry wind that blows downt he east slope of the Rocky Mountains.


Chemicals that destroy ozone in the atmosphere.


A circular basin in the high mountains carved by a glacier.


Very high, feathery-looking clouds made up of ice crystals.


The average weather for a place over a long period of time, typically determined by 30 years of daily records.


A collection of water moisture and ice crystals in the atmosphere.

cold front

The boundary between a mass of cold air and a mass of warm air where the cold air is pushing the warm air upward, creating a storm.


The transformation of water from gas (vapor) to liquid.


The place where two rivers or streams meet.

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