What are "Benchmark Glaciers" and what are the scientific objectives of the USGS "Benchmark Glaciers" Program?
The term “Benchmark Glaciers” refers to three North American glaciers that have been selected to be the subjects of a long-term glacier monitoring program which investigates climate, glacier geometry, glacier mass balance, glacier motion, and stream ru
Repeat photographs provide a good way to see how Alaska's glaciers are changing.
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.
“Eustacy” refers to a change in global sea level. For much of its multi-billion year history, Earth has experienced hundreds of periods of eustatic rise and eustatic fall of sea level.
How does present glacier extent and sea level compare to the extent of glaciers and global sea level during the Last Glacial Maximum (LGM)?
The Last Glacial Maximum (LGM) occurred about 20,000 years ago, during the last phase of the Pleistocene. At that time, glaciers covered: ~ 8 % of Earth’s surface ~ 25 % of Earth’s land area, and
Today, glaciers exists on every continent on Earth except Australia. If we use the analogy that 1,000 ice crystals represent all of the glacier ice on Planet Earth, then we learn that:
Temperate glaciers exist on the continents of North America, South America, Europe, Africa, and Asia, on both islands of New Zealand, and on the island of Irian Jaya.
Water is the most abundant chemical compound present on Earth's surface. About 2.1% of all of Earth's water is frozen in glaciers. If we use the analogy that 1,000 drops of water represent all of the water on Planet Earth, then we learn that:
Today, there are glaciers in both the United States and Canada. In the US, glaciers exist in Alaska, Washington, Oregon, California, Montana, Wyoming, Colorado, and Nevada.
About 99.3% of Earth’s glacier ice is located in the polar ice sheets, with about 91.4% in Antarctica and about 7.9% in Greenland. Therefore, the remaining glacier ice, about 0.7% is located in “temperate” ice caps, ice fields, and glaciers.