USGS scientist Louis Sass assesses an on-glacier weather station on the Kahiltna Glacier in Denali National Park, Alaska. This weather station is located at Kahiltna Base Camp, where climbers attempting to summit Denali begin their ascent. Sultana (Mt. Foraker) is visible in the background.
Was all of Alaska covered by glaciers during the Pleistocene Ice Age?
No--most of interior Alaska, south of the Brooks Range and north of the Alaska Range, was a non-glaciated grassland refuge habitat for a number of plant and animal species during the maximum Pleistocene glaciation. This ice-free corridor also provided one route for humans to move into North America.
Learn more: USGS Water Science School - Glaciers: Things to Know
Related
Which mountain in the conterminous U.S. has the most glaciers?
Mount Rainier, Washington, at 14,410 feet (4,393 meters), the highest peak in the Cascade Range, is a dormant volcano whose glacier ice cover exceeds that of any other mountain in the conterminous United States. Mount Rainier has approximately 26 glaciers. It contains more than five times the glacier area of all the other Cascade volcanoes combined. Mount Baker (Washington) at 10,778 feet (3,285...
How old is glacier ice?
The age of the oldest glacier ice in Antarctica may approach 1,000,000 years old The age of the oldest glacier ice in Greenland is more than 100,000 years old The age of the oldest Alaskan glacier ice ever recovered (from a basin between Mt. Bona and Mt. Churchill) is about 30,000 years old. Glacier flow moves newly formed ice through the entire length of a typical Alaskan valley glacier in 100...
Are today's glaciers leftovers from the Pleistocene ice age?
Yes and no. It depends on which glaciers you are considering. Parts of the Antarctic Continent have had continuous glacier cover for perhaps as long as 20 million years. Other areas, such as valley glaciers of the Antarctic Peninsula and glaciers of the Transantarctic Mountains may date from the early Pleistocene. For Greenland, ice cores and related data suggest that all of southern Greenland and...
Is glacier ice a type of rock?
Glacier ice, like limestone (for example), is a type of rock. Glacier ice is actually a mono-mineralic rock (a rock made of only one mineral, like limestone which is composed of the mineral calcite). The mineral ice is the crystalline form of water (H 2O). Most glacier ice forms through the metamorphism of tens of thousands of individual snowflakes into crystals of glacier ice. Each snowflake is a...
Where are glaciers found in continental North America?
Glaciers exist in both the United States and Canada. Most U.S. glaciers are in Alaska; others can be found in Washington, Oregon, California, Montana, Wyoming, Colorado, and Nevada (Wheeler Peak Glacier in Great Basin National Park). Utah’s Timpanogos Glacier is now a rock glacier (in which the ice is hidden by rocks), and Idaho’s Otto Glacier has melted away. Canada has glaciers in Alberta...
How would sea level change if all glaciers melted?
There is still some uncertainty about the full volume of glaciers and ice caps on Earth, but if all of them were to melt, global sea level would rise approximately 70 meters (approximately 230 feet), flooding every coastal city on the planet. Learn more: USGS Water Science School: Glaciers and Icecaps National Snow and Ice Data Center: Facts about Glaciers U.S. Global Change Research Program: Sea...
What is a glacier?
A glacier is a large, perennial accumulation of crystalline ice, snow, rock, sediment, and often liquid water that originates on land and moves down slope under the influence of its own weight and gravity. Typically, glaciers exist and may even form in areas where: mean annual temperatures are close to the freezing point winter precipitation produces significant accumulations of snow temperatures...
How long can we expect the present Interglacial period to last?
No one knows for sure. In the Devils Hole, Nevada paleoclimate record, the last four interglacials lasted over ~20,000 years with the warmest portion being a relatively stable period of 10,000 to 15,000 years duration. This is consistent with what is seen in the Vostok ice core from Antarctica and several records of sea level high stands. These data suggest that an equally long duration should be...
How many glaciers currently exist in Alaska?
Based on the most recent comprehensive survey in 2011, there were about 27,000 glaciers in Alaska. However, the number of glaciers is a misleading statistic. Scientists are more interested in total glacial land coverage as a measure. The number of glaciers is less important since large ones can split up into several as they retreat. The amount of area glaciers occupy in Alaska is trending downward...
How much of the Earth's water is stored in glaciers?
About 2.1% of all of Earth's water is frozen in glaciers. 97.2% is in the oceans and inland seas 2.1% is in glaciers 0.6% is in groundwater and soil moisture less than 1% is in the atmosphere less than 1% is in lakes and rivers less than 1% is in all living plants and animals. About three-quarters of Earth's freshwater is stored in glaciers. Therefore, glacier ice is the second largest reservoir...
Why is glacier ice blue?
Glacier ice is blue because the red (long wavelengths) part of white light is absorbed by ice and the blue (short wavelengths) light is transmitted and scattered. The longer the path light travels in ice, the more blue it appears. Learn more: USGS Water Science School - Glaciers: Things to Know
Weather station on Kahiltna Glacier
USGS scientist Louis Sass assesses an on-glacier weather station on the Kahiltna Glacier in Denali National Park, Alaska. This weather station is located at Kahiltna Base Camp, where climbers attempting to summit Denali begin their ascent. Sultana (Mt. Foraker) is visible in the background.
A researcher gazes across Wolverine Glacier and the surrounding snow-covered mountains
A researcher gazes across Wolverine Glacier and the surrounding snow-covered mountains during an early spring visit to collect mass balance data.
A researcher gazes across Wolverine Glacier and the surrounding snow-covered mountains during an early spring visit to collect mass balance data.
Crevassed terminus of Gulkana Glacier
Heavily crevassed terminus of Gulkana Glacier, AK, near the end of the 2016 ablation (melt) season.
Heavily crevassed terminus of Gulkana Glacier, AK, near the end of the 2016 ablation (melt) season.
Columbia Glacier in Prince William Sound, Alaska
Columbia Glacer in Prince William Sound, Alaska.
Columbia Glacer in Prince William Sound, Alaska.
Central Alaska Range
View of central Alaska Range from the south.
View of central Alaska Range from the south.
Portage, Burns and Shakespeare glaciers in Southcentral Alaska
Portage Glacier (right), Burns Glacier (center), Shakespeare Glacier (left) in Southcentral Alaska from the air.
Portage Glacier (right), Burns Glacier (center), Shakespeare Glacier (left) in Southcentral Alaska from the air.
Muir and Riggs Glaciers, Muir Inlet, Alaska - 1941
This northeast-looking photograph, on the southeastern side of White Thunder Ridge ,shows the lower reaches of Muir Glacier, then a large tidewater calving valley glacier, and its tributary Riggs Glacier. The séracs in the lower right-hand corner of the photograph mark Muir Glacier’s terminus. The ice thickness is more than 700 meters.
This northeast-looking photograph, on the southeastern side of White Thunder Ridge ,shows the lower reaches of Muir Glacier, then a large tidewater calving valley glacier, and its tributary Riggs Glacier. The séracs in the lower right-hand corner of the photograph mark Muir Glacier’s terminus. The ice thickness is more than 700 meters.
Exit Glacier, Alaska (In Full Retreat)
USGS ecologist Kevin Lafferty visits the Exit Glacier in Alaska.
USGS ecologist Kevin Lafferty visits the Exit Glacier in Alaska.
Related
Which mountain in the conterminous U.S. has the most glaciers?
Mount Rainier, Washington, at 14,410 feet (4,393 meters), the highest peak in the Cascade Range, is a dormant volcano whose glacier ice cover exceeds that of any other mountain in the conterminous United States. Mount Rainier has approximately 26 glaciers. It contains more than five times the glacier area of all the other Cascade volcanoes combined. Mount Baker (Washington) at 10,778 feet (3,285...
How old is glacier ice?
The age of the oldest glacier ice in Antarctica may approach 1,000,000 years old The age of the oldest glacier ice in Greenland is more than 100,000 years old The age of the oldest Alaskan glacier ice ever recovered (from a basin between Mt. Bona and Mt. Churchill) is about 30,000 years old. Glacier flow moves newly formed ice through the entire length of a typical Alaskan valley glacier in 100...
Are today's glaciers leftovers from the Pleistocene ice age?
Yes and no. It depends on which glaciers you are considering. Parts of the Antarctic Continent have had continuous glacier cover for perhaps as long as 20 million years. Other areas, such as valley glaciers of the Antarctic Peninsula and glaciers of the Transantarctic Mountains may date from the early Pleistocene. For Greenland, ice cores and related data suggest that all of southern Greenland and...
Is glacier ice a type of rock?
Glacier ice, like limestone (for example), is a type of rock. Glacier ice is actually a mono-mineralic rock (a rock made of only one mineral, like limestone which is composed of the mineral calcite). The mineral ice is the crystalline form of water (H 2O). Most glacier ice forms through the metamorphism of tens of thousands of individual snowflakes into crystals of glacier ice. Each snowflake is a...
Where are glaciers found in continental North America?
Glaciers exist in both the United States and Canada. Most U.S. glaciers are in Alaska; others can be found in Washington, Oregon, California, Montana, Wyoming, Colorado, and Nevada (Wheeler Peak Glacier in Great Basin National Park). Utah’s Timpanogos Glacier is now a rock glacier (in which the ice is hidden by rocks), and Idaho’s Otto Glacier has melted away. Canada has glaciers in Alberta...
How would sea level change if all glaciers melted?
There is still some uncertainty about the full volume of glaciers and ice caps on Earth, but if all of them were to melt, global sea level would rise approximately 70 meters (approximately 230 feet), flooding every coastal city on the planet. Learn more: USGS Water Science School: Glaciers and Icecaps National Snow and Ice Data Center: Facts about Glaciers U.S. Global Change Research Program: Sea...
What is a glacier?
A glacier is a large, perennial accumulation of crystalline ice, snow, rock, sediment, and often liquid water that originates on land and moves down slope under the influence of its own weight and gravity. Typically, glaciers exist and may even form in areas where: mean annual temperatures are close to the freezing point winter precipitation produces significant accumulations of snow temperatures...
How long can we expect the present Interglacial period to last?
No one knows for sure. In the Devils Hole, Nevada paleoclimate record, the last four interglacials lasted over ~20,000 years with the warmest portion being a relatively stable period of 10,000 to 15,000 years duration. This is consistent with what is seen in the Vostok ice core from Antarctica and several records of sea level high stands. These data suggest that an equally long duration should be...
How many glaciers currently exist in Alaska?
Based on the most recent comprehensive survey in 2011, there were about 27,000 glaciers in Alaska. However, the number of glaciers is a misleading statistic. Scientists are more interested in total glacial land coverage as a measure. The number of glaciers is less important since large ones can split up into several as they retreat. The amount of area glaciers occupy in Alaska is trending downward...
How much of the Earth's water is stored in glaciers?
About 2.1% of all of Earth's water is frozen in glaciers. 97.2% is in the oceans and inland seas 2.1% is in glaciers 0.6% is in groundwater and soil moisture less than 1% is in the atmosphere less than 1% is in lakes and rivers less than 1% is in all living plants and animals. About three-quarters of Earth's freshwater is stored in glaciers. Therefore, glacier ice is the second largest reservoir...
Why is glacier ice blue?
Glacier ice is blue because the red (long wavelengths) part of white light is absorbed by ice and the blue (short wavelengths) light is transmitted and scattered. The longer the path light travels in ice, the more blue it appears. Learn more: USGS Water Science School - Glaciers: Things to Know
Weather station on Kahiltna Glacier
USGS scientist Louis Sass assesses an on-glacier weather station on the Kahiltna Glacier in Denali National Park, Alaska. This weather station is located at Kahiltna Base Camp, where climbers attempting to summit Denali begin their ascent. Sultana (Mt. Foraker) is visible in the background.
USGS scientist Louis Sass assesses an on-glacier weather station on the Kahiltna Glacier in Denali National Park, Alaska. This weather station is located at Kahiltna Base Camp, where climbers attempting to summit Denali begin their ascent. Sultana (Mt. Foraker) is visible in the background.
A researcher gazes across Wolverine Glacier and the surrounding snow-covered mountains
A researcher gazes across Wolverine Glacier and the surrounding snow-covered mountains during an early spring visit to collect mass balance data.
A researcher gazes across Wolverine Glacier and the surrounding snow-covered mountains during an early spring visit to collect mass balance data.
Crevassed terminus of Gulkana Glacier
Heavily crevassed terminus of Gulkana Glacier, AK, near the end of the 2016 ablation (melt) season.
Heavily crevassed terminus of Gulkana Glacier, AK, near the end of the 2016 ablation (melt) season.
Columbia Glacier in Prince William Sound, Alaska
Columbia Glacer in Prince William Sound, Alaska.
Columbia Glacer in Prince William Sound, Alaska.
Central Alaska Range
View of central Alaska Range from the south.
View of central Alaska Range from the south.
Portage, Burns and Shakespeare glaciers in Southcentral Alaska
Portage Glacier (right), Burns Glacier (center), Shakespeare Glacier (left) in Southcentral Alaska from the air.
Portage Glacier (right), Burns Glacier (center), Shakespeare Glacier (left) in Southcentral Alaska from the air.
Muir and Riggs Glaciers, Muir Inlet, Alaska - 1941
This northeast-looking photograph, on the southeastern side of White Thunder Ridge ,shows the lower reaches of Muir Glacier, then a large tidewater calving valley glacier, and its tributary Riggs Glacier. The séracs in the lower right-hand corner of the photograph mark Muir Glacier’s terminus. The ice thickness is more than 700 meters.
This northeast-looking photograph, on the southeastern side of White Thunder Ridge ,shows the lower reaches of Muir Glacier, then a large tidewater calving valley glacier, and its tributary Riggs Glacier. The séracs in the lower right-hand corner of the photograph mark Muir Glacier’s terminus. The ice thickness is more than 700 meters.
Exit Glacier, Alaska (In Full Retreat)
USGS ecologist Kevin Lafferty visits the Exit Glacier in Alaska.
USGS ecologist Kevin Lafferty visits the Exit Glacier in Alaska.
Updated Date: March 25, 2025