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.

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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...

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...

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...

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...

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...

Is glacier ice a type of rock?

Yes – glacier ice, like granite, 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). It forms through the metamorphism of tens of thousands of individual snowflakes into crystals of...

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). Reputedly, Utah’s Timpanogos Glacier is now a rock glacier (in which the ice is hidden by rocks), and Idaho’s Otto...

Why is glacier ice 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.

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...

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...

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...
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Date published: September 28, 2016

Fifty Years of Glacier Change Research in Alaska

ANCHORAGE, Alaska — This year marks the 50th anniversary of one of the longest continuous glacier research efforts in North America.

Date published: January 5, 2016

First Ever Digital Geologic Map of Alaska Published

ANCHORAGE, Alaska – A new digital geologic map of Alaska is being released today providing land users, managers and scientists geologic information for the evaluation of land use in relation to resource extraction, conservation, natural hazards and recreation.

Date published: March 18, 2015

From Icefield to Ocean - What Glacier Change Might Mean for the Future of Alaska

Frozen bodies of ice cover nearly 10 percent of the state of Alaska, but the influence of glaciers on the environment, tourism, fisheries, hydropower, and other important Alaska resources is rarely discussed.

Date published: January 20, 2015

Melting Glaciers Increase the Flow of Carbon to Downstream Ecosystems

ANCHORAGE, Alaska Melting glaciers are not just impacting sea level, they are also affecting the flow of organic carbon to the world’s oceans, according to new research that provides the first ever global-scale estimates for the storage and release of organic carbon from glaciers.

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Gilkey Glacier, Juneau Icefield, Alaska
December 31, 2017

Gilkey Glacier, Juneau Icefield, Alaska

Interactions between glaciers, bedrock, and surface debris on the Gilkey Glacier, Juneau Icefield, Alaska.

Photo flat glacier surface, Juneau Icefield, Alaska
December 31, 2016

Flat glacier surface, Juneau Icefield, Alaska

An ideal ice core site is the highest, flattest glacier in a region. In 2016, a transect of 7-9 m ice cores was drilled on the Matthes Glacier, Juneau Icefield to determine if recent fires are affecting the glacier surface. (Photo: Lucas Foglia, used with permission)

Image shows a satellite view of Glacier Bay National Park
September 14, 2016

Landsat View of Glacier Bay

A view of Glacier Bay National Park, taken on September 13, 2015. Credit: USGS/NASA Landsat Program.

Alaska Topographic Map Contours on Glacier
April 25, 2016

Alaska Map with Contours on Glacier

Alaska US Topo map sample image of contours over Chedotlothna Glacier in Denali National Park and Preserve.

Image: Alaskan Glacier
June 1, 2005

Alaskan Glacier

Near Seward, Alaska

Image: Central Alaska Range
November 7, 2002

Central Alaska Range

View of central Alaska Range from the south.

Image: Muir and Riggs Glaciers, Muir Inlet, Alaska - 1941
August 13, 1941

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. Muir Glacier had been retreating

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Image: Exit Glacier, Alaska (In Full Retreat)

Exit Glacier, Alaska (In Full Retreat)

USGS ecologist Kevin Lafferty visits the Exit Glacier in Alaska.

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