An ice core is a core sample from the accumulation of snow and ice over many years that have recrystallized and have trapped air bubbles from previous time periods.
The composition of these ice cores, especially the presence of hydrogen and oxygen isotopes, provides a picture of the climate at the time.
Because water molecules containing heavier isotopes exhibit a lower vapor pressure, when the temperature falls, the heavier water molecules will condense faster than the normal water molecules.
The relative concentrations of the heavier isotopes in the condensate indicate the temperature of condensation at the time, allowing for ice cores to be used in global temperature reconstruction.
In addition to the isotope concentration, the air bubbles trapped in the ice cores allow for measurement of the atmospheric concentrations of trace gases, including greenhouse gases carbon dioxide, methane, and nitrous oxide.
The air bubbles may also contain traces of aerosols, which are produced in great concentrations during volcanic eruptions.
Greenland ice sheet The Greenland Ice Sheet is a vast body of ice covering roughly 80% of the surface of Greenland. It is the second largest ice body in the world, after ... >
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Ice shelf An ice shelf is a thick, floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface, ... >
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Temperature record The temperature record shows the fluctuations of the temperature of the atmosphere and the oceans through various spans of time. The most detailed ... >
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Antarctic ice sheet The Antarctic ice sheet is the largest single mass of ice on Earth. It covers an area of almost 14 million square km and contains 30 million cubic km ... >
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Ice sheet An Ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 square kilometers (19,305 square miles). The only ... >
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Geologic temperature record This article is devoted to temperature changes in Earth's environment as determined from geologic evidence on multi-million to billion (109) year ... >
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Fog Fog is a cloud in contact with the ground. Fog differs from other clouds only in that fog touches the surface of the Earth. The same cloud that is ... >
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