A new rift is forming across the Petermann Glacier. If this rift connects to existing rifts, it could result in another large iceberg breaking free.
At the USGS EROS Center, we study land change, operate the Landsat satellites, and maintain the longest, continuously acquired collection of images of the Earth's land surface.
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 throughout the rest of the year do not result in the complete loss of the previous winter’s snow accumulation
Over multiple decades this continuing accumulation of snow results in the presence of a large enough mass of snow for the metamorphism from snow to glacier ice process to begin. Glaciers are classified by their size (i.e. ice sheet, ice cap, valley glacier, cirque glacier), location, and thermal regime (i.e., polar vs. temperate). Glaciers are sensitive indicators of changing climate.
Learn more: USGS Water Science School: Glaciers and Icecaps
Related
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...
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...
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 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 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...
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
Do ice worms exist?
Yes, ice worms do, in fact, exist! They are small worms that live in glacial ice in Alaska, Washington, Oregon, and British Columbia; they have not been found in glaciers elsewhere. Contrary to stories and songs, they do not give glacier ice its blue color and they don't grow to lengths of 50 feet. These myths were made popular by poet Robert Service and the annual Cordova Iceworm Festival in...
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 2 O). Most glacier ice forms through the metamorphism of tens of thousands of individual snowflakes into crystals of glacier ice. Each snowflake is...
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
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...
Where are Earth’s glaciers located?
Glaciers exist on every continent except Australia. Approximate distribution is: 91% in Antarctica 8% in Greenland Less than 0.5% in North America (about 0.1% in Alaska) 0.2% in Asia Less than 0.1% are in South America, Europe, Africa, New Zealand, and Indonesia.
What are the impacts of glacier loss, other than losing an aesthetic landscape feature?
Glaciers act as reservoirs of water that persist through summer. Continual melt from glaciers contributes water to the ecosystem throughout dry months, creating perennial stream habitat and a water source for plants and animals. The cold runoff from glaciers also affects downstream water temperatures. Many aquatic species in mountainous environments require cold water temperatures to survive. Some...
Image of the Week - New Rift on Greenland's Petermann Glacier
A new rift is forming across the Petermann Glacier. If this rift connects to existing rifts, it could result in another large iceberg breaking free.
At the USGS EROS Center, we study land change, operate the Landsat satellites, and maintain the longest, continuously acquired collection of images of the Earth's land surface.
Image of the Week - Pine Island Glacier’s Newest Iceberg
These Landsat 8 images show the latest iceberg to break free in Antarctica's Pine Island. Warmer ocean waters are melting the ice from beneath, causing increasing instability.
These Landsat 8 images show the latest iceberg to break free in Antarctica's Pine Island. Warmer ocean waters are melting the ice from beneath, causing increasing instability.
USGS Public Lecture: Warm Ice—Dynamics of Rapidly Changing Glaciers
- Glacier Numerology – The how big, how long, how thick, how much, how often, of glacier science.
- Glacier Photography – While a picture may be worth a thousand words, a collection of images may tell a complete forensic story.
- Glacier Numerology – The how big, how long, how thick, how much, how often, of glacier science.
- Glacier Photography – While a picture may be worth a thousand words, a collection of images may tell a complete forensic story.
Monitoring glaciers in Glacier National Park.
Monitoring glaciers in Glacier National Park.
Monitoring glaciers in Glacier National Park.
Petermann Glacier
Located on the northwestern coast of Greenland, Petermann Glacier covers 1,295 square kilometers (500 square miles). The glacier's floating tongue of ice extends from the lower right corner of the image toward the top center. At 15–20 kilometers (9–12 miles) wide and 70 kilometers (43 miles) long, it is the longest floating glacier in the Northern Hemisphere.
Located on the northwestern coast of Greenland, Petermann Glacier covers 1,295 square kilometers (500 square miles). The glacier's floating tongue of ice extends from the lower right corner of the image toward the top center. At 15–20 kilometers (9–12 miles) wide and 70 kilometers (43 miles) long, it is the longest floating glacier in the Northern Hemisphere.
Getting the Shot, Grinnell Glacier, Glacier National Park.
USGS scientist shoots a repeat photograph of Grinnell Glacier in Glacier National Park to illustrate glacial recession due to impacts of climate change.
*note – logo on scientists hat is logo from USGS Northern Rocky Mountain Science Center, not private.
USGS scientist shoots a repeat photograph of Grinnell Glacier in Glacier National Park to illustrate glacial recession due to impacts of climate change.
*note – logo on scientists hat is logo from USGS Northern Rocky Mountain Science Center, not private.
USGS Public Lecture Series: Baked Alaska--What's Happening to the Glaciers in Alaska?
Glaciers are Earth's largest reservoir of freshwater. As they change, so does global sea level. Alaska has one of the largest accumulations of glaciers anywhere on Earth outside of the Polar regions. For most of the past half century, Alaska has experienced a significant increase in temperature that has profoundly impacted its glaciers. Join USGS scientist Dr.
Glaciers are Earth's largest reservoir of freshwater. As they change, so does global sea level. Alaska has one of the largest accumulations of glaciers anywhere on Earth outside of the Polar regions. For most of the past half century, Alaska has experienced a significant increase in temperature that has profoundly impacted its glaciers. Join USGS scientist Dr.
Surprise Glacier
Surprise Glacier, Harriman Fiord, western Prince William Sound.
Surprise Glacier, Harriman Fiord, western Prince William Sound.
Surprise Glacier
Surprise Glacier (in background), Harriman Fiord, western Prince William Sound.
Surprise Glacier (in background), Harriman Fiord, western Prince William Sound.
Barry Glacier
Barry Glacier, Barry Arm, western Prince William Sound.
Barry Glacier, Barry Arm, western Prince William Sound.
Denali Fault: Canwell Glacier
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
Related
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...
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...
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 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 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...
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
Do ice worms exist?
Yes, ice worms do, in fact, exist! They are small worms that live in glacial ice in Alaska, Washington, Oregon, and British Columbia; they have not been found in glaciers elsewhere. Contrary to stories and songs, they do not give glacier ice its blue color and they don't grow to lengths of 50 feet. These myths were made popular by poet Robert Service and the annual Cordova Iceworm Festival in...
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 2 O). Most glacier ice forms through the metamorphism of tens of thousands of individual snowflakes into crystals of glacier ice. Each snowflake is...
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
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...
Where are Earth’s glaciers located?
Glaciers exist on every continent except Australia. Approximate distribution is: 91% in Antarctica 8% in Greenland Less than 0.5% in North America (about 0.1% in Alaska) 0.2% in Asia Less than 0.1% are in South America, Europe, Africa, New Zealand, and Indonesia.
What are the impacts of glacier loss, other than losing an aesthetic landscape feature?
Glaciers act as reservoirs of water that persist through summer. Continual melt from glaciers contributes water to the ecosystem throughout dry months, creating perennial stream habitat and a water source for plants and animals. The cold runoff from glaciers also affects downstream water temperatures. Many aquatic species in mountainous environments require cold water temperatures to survive. Some...
Image of the Week - New Rift on Greenland's Petermann Glacier
A new rift is forming across the Petermann Glacier. If this rift connects to existing rifts, it could result in another large iceberg breaking free.
At the USGS EROS Center, we study land change, operate the Landsat satellites, and maintain the longest, continuously acquired collection of images of the Earth's land surface.
A new rift is forming across the Petermann Glacier. If this rift connects to existing rifts, it could result in another large iceberg breaking free.
At the USGS EROS Center, we study land change, operate the Landsat satellites, and maintain the longest, continuously acquired collection of images of the Earth's land surface.
Image of the Week - Pine Island Glacier’s Newest Iceberg
These Landsat 8 images show the latest iceberg to break free in Antarctica's Pine Island. Warmer ocean waters are melting the ice from beneath, causing increasing instability.
These Landsat 8 images show the latest iceberg to break free in Antarctica's Pine Island. Warmer ocean waters are melting the ice from beneath, causing increasing instability.
USGS Public Lecture: Warm Ice—Dynamics of Rapidly Changing Glaciers
- Glacier Numerology – The how big, how long, how thick, how much, how often, of glacier science.
- Glacier Photography – While a picture may be worth a thousand words, a collection of images may tell a complete forensic story.
- Glacier Numerology – The how big, how long, how thick, how much, how often, of glacier science.
- Glacier Photography – While a picture may be worth a thousand words, a collection of images may tell a complete forensic story.
Monitoring glaciers in Glacier National Park.
Monitoring glaciers in Glacier National Park.
Monitoring glaciers in Glacier National Park.
Petermann Glacier
Located on the northwestern coast of Greenland, Petermann Glacier covers 1,295 square kilometers (500 square miles). The glacier's floating tongue of ice extends from the lower right corner of the image toward the top center. At 15–20 kilometers (9–12 miles) wide and 70 kilometers (43 miles) long, it is the longest floating glacier in the Northern Hemisphere.
Located on the northwestern coast of Greenland, Petermann Glacier covers 1,295 square kilometers (500 square miles). The glacier's floating tongue of ice extends from the lower right corner of the image toward the top center. At 15–20 kilometers (9–12 miles) wide and 70 kilometers (43 miles) long, it is the longest floating glacier in the Northern Hemisphere.
Getting the Shot, Grinnell Glacier, Glacier National Park.
USGS scientist shoots a repeat photograph of Grinnell Glacier in Glacier National Park to illustrate glacial recession due to impacts of climate change.
*note – logo on scientists hat is logo from USGS Northern Rocky Mountain Science Center, not private.
USGS scientist shoots a repeat photograph of Grinnell Glacier in Glacier National Park to illustrate glacial recession due to impacts of climate change.
*note – logo on scientists hat is logo from USGS Northern Rocky Mountain Science Center, not private.
USGS Public Lecture Series: Baked Alaska--What's Happening to the Glaciers in Alaska?
Glaciers are Earth's largest reservoir of freshwater. As they change, so does global sea level. Alaska has one of the largest accumulations of glaciers anywhere on Earth outside of the Polar regions. For most of the past half century, Alaska has experienced a significant increase in temperature that has profoundly impacted its glaciers. Join USGS scientist Dr.
Glaciers are Earth's largest reservoir of freshwater. As they change, so does global sea level. Alaska has one of the largest accumulations of glaciers anywhere on Earth outside of the Polar regions. For most of the past half century, Alaska has experienced a significant increase in temperature that has profoundly impacted its glaciers. Join USGS scientist Dr.
Surprise Glacier
Surprise Glacier, Harriman Fiord, western Prince William Sound.
Surprise Glacier, Harriman Fiord, western Prince William Sound.
Surprise Glacier
Surprise Glacier (in background), Harriman Fiord, western Prince William Sound.
Surprise Glacier (in background), Harriman Fiord, western Prince William Sound.
Barry Glacier
Barry Glacier, Barry Arm, western Prince William Sound.
Barry Glacier, Barry Arm, western Prince William Sound.
Denali Fault: Canwell Glacier
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.