The cryosphere is every part of Earth where water is frozen: snow, glaciers, ice sheets, ice shelves, freshwater ice, sea ice and permafrost. It is both a climate indicator and a climate regulator.
- Surface ice and snow store fresh water and make Earth's surface bright white, controlling how much sunlight is absorbed or reflected.
- Below ground, permafrost and ground ice hold water and other materials — carbon, nutrients, heavy metals, even viruses. Storing carbon in permafrost is one way the cryosphere regulates climate.
- It spans the planet, from the subtropical Himalayas to the Arctic and Antarctica, and touches the lithosphere, biosphere, atmosphere and hydrosphere.
Thawing permafrost drives coastal erosion. Photograph by Brandt Meixell, U.S. Geological Survey.
Why it matters
| Frozen water | What's at stake |
|---|---|
| Snow | About 50 percent of runoff in the western United States comes from snowmelt; on average 27 people die in snow avalanches every year |
| Glaciers | Melting glaciers and ice sheets, plus ocean water expanding as it warms, are expected to raise sea level at least 43 centimeters by 2100; hundreds of millions of coastal residents will likely be affected, and more by the displacement it causes |
| Sea ice | Arctic September sea ice is shrinking, opening new shipping routes, changing how storms hit coasts and endangering wildlife; the Arctic Ocean hasn't been seasonally ice-free in more than 100,000 years |
| Permafrost | Holds twice as much carbon as the atmosphere; USGS scientists are working globally to pin down how its thaw feeds back on climate |
Wet slab avalanche debris in Glacier National Park, Montana. U.S. Geological Survey.
Who relies on USGS cryosphere research
The cryosphere is changing fast, with cascading effects on water supplies, ecosystems, sea level, climate feedbacks and hazards such as avalanches, floods, droughts, landslides and coastal erosion. The USGS provides unbiased data to:
- NASA — ground validation for satellite and airborne missions such as ICESat-2;
- the Departments of Defense and Transportation — sea ice, permafrost and snow assessments for transportation corridors and national security, through efforts like the USGS Snow and Avalanche Project and Arctic sea-ice research;
- policymakers — research behind the Fifth National Climate Assessment and the IPCC's Special Report on the Ocean and Cryosphere;
- federal, tribal and state land managers — current and future snow, ice and permafrost conditions, through USGS permafrost research, the Next Generation Water Observing System, a high-resolution Crown of the Continent Snowpack dataset for Glacier National Park, the Benchmark Glacier Project and the From Snow to Flow web page;
- NOAA — projections of glacier and ice-sheet contributions to sea-level rise, and USGS measurements of mountain glacier change;
- the U.S. Fish and Wildlife Service — how the changing cryosphere threatens species such as the western glacier stonefly;
- local communities — information for subsistence harvest, food storage, hazards and infrastructure; USGS avalanche research supports forecasts that keep recreationists and commerce corridors safe.
Sunset over Arctic Ocean sea ice. Photograph by Jessica Robertson, U.S. Geological Survey.
USGS researchers collect a permafrost core. Photograph by Miriam Jones, U.S. Geological Survey.
The Garden Wall station, a high-elevation climate and weather monitoring site in Glacier National Park. Photograph by Erich Peitzsch, U.S. Geological Survey.
USGS cryosphere science helps everyone who depends on it understand how snow, glaciers, permafrost and sea ice regulate and respond to Earth's climate — and how they connect to people, plants and animals.
Sources
Based on U.S. Geological Survey Fact Sheet 2024–3043, "Cryospheric sciences at the U.S. Geological Survey"; a work of the United States government in the public domain.
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