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Definition
| The breaking away of a block of ice, usually from the front of a tidewater glacier, that produces an iceberg |
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Term
| chlorofluorocarbons (CFCs) |
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Definition
| A group of compounds that, on escape to the atmosphere, break down, releasing chlorine atoms that destroy ozone molecules; for example, Freon, which is widely used in refrigeration, air-conditioning, and formerly was a propellant in aerosol-spray cans. |
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Definition
| The relatively constant factors that dictate a region’s climate. |
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Term
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Definition
A condition peculiar to motion on a rotating body such as Earth. It appears to deflect moving objects in the Northern Hemisphere to the right and objects in the Southern Hemisphere to the
left, to an observer on the rotating body. |
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Term
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Definition
| The deviation of the earth’s path around the sun from a perfect circle. |
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Term
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Definition
| A moraine that is produced at the front of an actively flowing glacier; a moraine that has been deposited at the lower end of a glacier. |
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Term
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Definition
| The belt of low-pressure air masses near the equator. (See doldrums.) |
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Term
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Definition
| A rock fragment that has been carried by glacial ice or floating ice and deposited when the ice melted at some distance from the outcrop from which it was derived. |
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Term
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Definition
| A narrow, steep-walled inlet of the sea between cliffs or steep slopes, formed by the passage of a glacier. A drowned glacial valley. |
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Term
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Definition
| A transitional material between snow and glacial ice, being older and denser than snow, but not yet transformed into glacial ice. Snow becomes firn after surviving one summer melt season; firn becomes ice when its permeability to liquid water becomes zero |
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Term
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Definition
| Deposits of stratified sand, gravel, and silt that have been removed from a glacier by meltwater streams. |
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Term
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Definition
| A large mass of ice formed, at least in part, on land by the compaction and recrystallization of snow. It moves slowly downslope by creep or outward in all directions due to the stress of its weight, and it survives from year to year. |
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Term
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Definition
| The general term for the steady rise in the average global temperatures over the last 100 years. |
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Term
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Definition
| The warming of the atmosphere by an increase in the amount of certain gases in the atmosphere, primarily CO2 and CH4, that increase the retention of heat that has been radiated by the earth. |
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Term
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Definition
| Uplift of the crust of the earth that results from unloading such as results from the melting of ice sheets. |
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Definition
A bowl-shaped depression without surface drainage in glacial-drift deposits, often containing a lake, believed to have formed by the melting of a large detached block of stagnant ice left behind by a
retreating glacier. |
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Term
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Definition
| A mound, ridge, hill, or other distinct accumulation of unsorted, unstratified glacial drift, predominantly till, deposited chiefly by direct action of glacial ice in a variety of landforms. |
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Term
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Definition
| The tilt of the earth’s axis. |
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Term
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Definition
| The boundary in the atmosphere where cold polar surface air and mild-temperature surface air converge. |
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Term
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Definition
| The region of cold, high-density air that exists in the polar regions. |
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Term
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Definition
| The slow gyration of the Earth’s axis, analogous to that of a spinning top, which causes the slow change in the orientation of the Earth’s axis relative to the sun that accounts for the reversal of the seasons of winter and summer in the Northern and Southern Hemispheres every 11,500 years. |
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Term
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Definition
| An ice-marginal lake formed just beyond the frontal moraine of a retreating glacier and generally in direct contact with the ice. |
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Term
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Definition
| One of a series of nested end moraines that record the stepwise retreat of a glacier at the end of an ice age. |
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Term
| subtropical highs (horse latitudes): |
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Definition
| The climatic belts at latitudes of approximately 30°-35° north and and south of the equator characterized by semi-permanent high-pressure air masses, moderate seasonal rainfall, summer heat, dryness, and generally clear skies. |
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Term
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Definition
| : A glacier that alternates periodically between brief periods (usually 1-4 years) of very rapid flow, called surges, and longer periods (usually 10-100 years) of near stagnation. |
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Term
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Definition
| Unsorted and unstratified drift, generally unconsolidated, that is deposited directly by and beneath a glacier without subsequent reworking by water from the glacier. |
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Term
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Definition
| A process whereby cold, nutrient-rich water is brought to the surface. Coastal upwelling occurs mostly in trade-wind belts. |
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Term
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Definition
| The movement of air from a region of high pressure to a region of low pressure. |
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Term
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Definition
| The lower part of a glacier that deforms due to the glacier’s own weight. |
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