The water stored in ice and glaciers moves slowly through are part of the water cycle, even though the water in them moves very slowly. Did you know? Ice caps influence the weather, too. The color white reflects sunlight (heat) more than darker colors, and as ice is so white, sunlight is reflected back out to the sky, which helps to create weather patterns.
• Water Science School HOME • The Water Cycle •
Water cycle components » Atmosphere · Condensation · Evaporation · Evapotranspiration · Freshwater lakes and rivers · Groundwater flow · Groundwater storage · Ice and snow · Infiltration · Oceans · Precipitation · Snowmelt · Springs · Streamflow · Sublimation · Surface runoff
Credit: NASA
Water stored as ice is part of the water cycle
The water cycle describes how water moves above, on, and through the Earth. But, in fact, much more water is "in storage" at any one time than is actually moving through the cycle. By storage, we mean water that is locked up in its present state for a relatively long period of time; we call these storage places pools within the water cycle.
Short-term storage might be days or weeks for water in a lake, but it could be thousands of years for deep groundwater storage or even longer for water at the bottom of an ice cap, such as in Greenland. In the grand scheme of things, this water is still part of the water cycle.
At high elevations or latitudes where snowpack persists year-round, the weight of the accumulated snow compresses it into ice. When the ice forms in a steep mountain environment, it slowly flows downhill, forming a glacier. Ice sheets are glaciers that have spread outward to cover an area larger than 50,000 square kilometers. Ice sheets and glaciers are a water cycle pool.
Ice caps around the world
The white areas in this map show glaciers and ice sheets around the world. The vast majority, almost 90 percent, of Earth's ice mass is in Antarctica, while the Greenland ice cap contains 10 percent of the total global ice mass. The Greenland ice cap is an interesting part of the water cycle. The ice cap became so large over time (about 600,000 cubic miles (mi3) or 2.5 million cubic kilometers (km3)) because more snow fell than melted. Over the millennia, as the snow got deeper, it compressed and became ice. The ice cap averages about 5,000 feet (1,500 meters) in thickness, but can be as thick as 14,000 feet (4,300 meters). The ice is so heavy that the land below it has been pressed down into the shape of a bowl. In many places, glaciers on Greenland reach to the sea, and one estimate is that as much as 125 mi3 (517 km3) of ice "calves" into the ocean each year—one of Greenland's contributions to the global water cycle. Ocean-bound icebergs travel with the currents, melting along the way. Some icebergs have been seen, in much smaller form, as far south as the island of Bermuda.
Ice and glaciers come and go, daily and over millennia
The climate, on a global scale, is always changing, although usually not at a rate fast enough for people to notice. There have been many warm periods, such as when the dinosaurs lived (about 100 million years ago) and many cold periods, such as the last ice age of about 18,000 years ago. During the last ice age much of the northern hemisphere was covered in ice and glaciers. This map indicates by the surface air temperature, ice and glaciers likely covered nearly all of Canada, much of northern Asia and Europe, and extended well into the United States.
Glaciers are still around today; tens of thousands of them are in Alaska. Climatic factors still affect them today and during the current warmer climate, they can retreat in size at a rate easily measured on a yearly scale. Read more about what a changing climate means for glaciers.
Glaciers worldwide are shrinking in size
This picture shows the Grinnell Glacier in Glacier National Park, Montana, USA in 2005. The glacier has been retreating rapidly since the early 1900's. The year markers point to the former extent of the glacier in 1850, 1937, 1968, and 1981. Mountain glaciers are excellent monitors of climate change; the worldwide shrinkage of mountain glaciers is thought to be caused by a combination of a temperature increase since the Little Ice Age, which ended in the latter half of the 19th century, and increased greenhouse-gas emissions.
Ice caps influence the weather
Just because water in an ice cap or glacier is not moving does not mean that it does not have a direct effect on other aspects of the water cycle, the weather, and the climate. Ice is very white, and since white reflects sunlight (and thus, heat), large ice fields can determine weather patterns. Air temperatures can be higher a mile above ice caps than at the surface, and wind patterns, which affect weather systems, can be dramatic around ice-covered landscapes.
Read more about how glaciers are important indicators of a changing climate on this EPA page.[F(1]
Ice caps and global water distribution
Even though the amount of water locked up in glaciers and ice caps is a small percentage of all water on (and in) the Earth, it represents a large percentage of the world's total freshwater. As these charts and the data table show, the amount of water locked up in ice and snow is only about 1.7 percent of all water on Earth, but the majority of total freshwater on Earth, about 68.7 percent, is held in ice caps and glaciers.
One estimate of global water distribution
| Water source | Water volume, in cubic miles | Water volume, in cubic kilometers | Percent of total water | Percent of total freshwater |
|---|---|---|---|---|
| Ice caps, Glaciers, & Permanent snow | 5,773,000 | 24,064,000 | 1.7% | 68.7% |
| Total global freshwater | 8,404,000 | 35,030,000 | 2.5% | -- |
| Total global water | 332,500,000 | 1,386,000,000 | -- | -- |
Source: Gleick, P. H., 1996: Water resources. In Encyclopedia of Climate and Weather, ed. by S. H. Schneider, Oxford University Press, New York, vol. 2, pp. 817-823.
Sources and more information
- Glacier Studies - USGS Northern Rocky Mountain Science Center
- Glacier Facts & Figures, National Snow & Ice Data Center
- Greatest Places Physical Geography: Greenland
More topics and other components of the water cycle:
Precipitation and the Water Cycle
Streamflow and the Water Cycle
Snowmelt Runoff and the Water Cycle
Evaporation and the Water Cycle
The Atmosphere and the Water Cycle
Condensation and the Water Cycle
Infiltration and the Water Cycle
Sublimation and the Water Cycle
Surface Runoff and the Water Cycle
Ice, Snow, and Glaciers and the Water Cycle
Groundwater Flow and the Water Cycle
Groundwater Storage and the Water Cycle
The water stored in ice and glaciers moves slowly through are part of the water cycle, even though the water in them moves very slowly. Did you know? Ice caps influence the weather, too. The color white reflects sunlight (heat) more than darker colors, and as ice is so white, sunlight is reflected back out to the sky, which helps to create weather patterns.
• Water Science School HOME • The Water Cycle •
Water cycle components » Atmosphere · Condensation · Evaporation · Evapotranspiration · Freshwater lakes and rivers · Groundwater flow · Groundwater storage · Ice and snow · Infiltration · Oceans · Precipitation · Snowmelt · Springs · Streamflow · Sublimation · Surface runoff
Credit: NASA
Water stored as ice is part of the water cycle
The water cycle describes how water moves above, on, and through the Earth. But, in fact, much more water is "in storage" at any one time than is actually moving through the cycle. By storage, we mean water that is locked up in its present state for a relatively long period of time; we call these storage places pools within the water cycle.
Short-term storage might be days or weeks for water in a lake, but it could be thousands of years for deep groundwater storage or even longer for water at the bottom of an ice cap, such as in Greenland. In the grand scheme of things, this water is still part of the water cycle.
At high elevations or latitudes where snowpack persists year-round, the weight of the accumulated snow compresses it into ice. When the ice forms in a steep mountain environment, it slowly flows downhill, forming a glacier. Ice sheets are glaciers that have spread outward to cover an area larger than 50,000 square kilometers. Ice sheets and glaciers are a water cycle pool.
Ice caps around the world
The white areas in this map show glaciers and ice sheets around the world. The vast majority, almost 90 percent, of Earth's ice mass is in Antarctica, while the Greenland ice cap contains 10 percent of the total global ice mass. The Greenland ice cap is an interesting part of the water cycle. The ice cap became so large over time (about 600,000 cubic miles (mi3) or 2.5 million cubic kilometers (km3)) because more snow fell than melted. Over the millennia, as the snow got deeper, it compressed and became ice. The ice cap averages about 5,000 feet (1,500 meters) in thickness, but can be as thick as 14,000 feet (4,300 meters). The ice is so heavy that the land below it has been pressed down into the shape of a bowl. In many places, glaciers on Greenland reach to the sea, and one estimate is that as much as 125 mi3 (517 km3) of ice "calves" into the ocean each year—one of Greenland's contributions to the global water cycle. Ocean-bound icebergs travel with the currents, melting along the way. Some icebergs have been seen, in much smaller form, as far south as the island of Bermuda.
Ice and glaciers come and go, daily and over millennia
The climate, on a global scale, is always changing, although usually not at a rate fast enough for people to notice. There have been many warm periods, such as when the dinosaurs lived (about 100 million years ago) and many cold periods, such as the last ice age of about 18,000 years ago. During the last ice age much of the northern hemisphere was covered in ice and glaciers. This map indicates by the surface air temperature, ice and glaciers likely covered nearly all of Canada, much of northern Asia and Europe, and extended well into the United States.
Glaciers are still around today; tens of thousands of them are in Alaska. Climatic factors still affect them today and during the current warmer climate, they can retreat in size at a rate easily measured on a yearly scale. Read more about what a changing climate means for glaciers.
Glaciers worldwide are shrinking in size
This picture shows the Grinnell Glacier in Glacier National Park, Montana, USA in 2005. The glacier has been retreating rapidly since the early 1900's. The year markers point to the former extent of the glacier in 1850, 1937, 1968, and 1981. Mountain glaciers are excellent monitors of climate change; the worldwide shrinkage of mountain glaciers is thought to be caused by a combination of a temperature increase since the Little Ice Age, which ended in the latter half of the 19th century, and increased greenhouse-gas emissions.
Ice caps influence the weather
Just because water in an ice cap or glacier is not moving does not mean that it does not have a direct effect on other aspects of the water cycle, the weather, and the climate. Ice is very white, and since white reflects sunlight (and thus, heat), large ice fields can determine weather patterns. Air temperatures can be higher a mile above ice caps than at the surface, and wind patterns, which affect weather systems, can be dramatic around ice-covered landscapes.
Read more about how glaciers are important indicators of a changing climate on this EPA page.[F(1]
Ice caps and global water distribution
Even though the amount of water locked up in glaciers and ice caps is a small percentage of all water on (and in) the Earth, it represents a large percentage of the world's total freshwater. As these charts and the data table show, the amount of water locked up in ice and snow is only about 1.7 percent of all water on Earth, but the majority of total freshwater on Earth, about 68.7 percent, is held in ice caps and glaciers.
One estimate of global water distribution
| Water source | Water volume, in cubic miles | Water volume, in cubic kilometers | Percent of total water | Percent of total freshwater |
|---|---|---|---|---|
| Ice caps, Glaciers, & Permanent snow | 5,773,000 | 24,064,000 | 1.7% | 68.7% |
| Total global freshwater | 8,404,000 | 35,030,000 | 2.5% | -- |
| Total global water | 332,500,000 | 1,386,000,000 | -- | -- |
Source: Gleick, P. H., 1996: Water resources. In Encyclopedia of Climate and Weather, ed. by S. H. Schneider, Oxford University Press, New York, vol. 2, pp. 817-823.
Sources and more information
- Glacier Studies - USGS Northern Rocky Mountain Science Center
- Glacier Facts & Figures, National Snow & Ice Data Center
- Greatest Places Physical Geography: Greenland
More topics and other components of the water cycle: