Non-polar ice core

A non-polar ice core is an ice core taken south of the arctic circle or north of the antarctic circle. These are often from atop an ice sheet, ice cap, ice field, or from a high mountain glacier. The non-polar ice caps, such as found on mountain tops, are traditionally ignored as serious places to drill ice cores because the ice may not be more than a few thousand years old. However, since the 1970s ice has been found that is older, with clear chronological dating and climate signals going as far back as the beginning of the most recent ice age. Although polar cores have the clearest and longest chronological record, four-times or more as long, ice cores from tropical regions offer data and insights not available from polar cores and have been very influential in advancing understanding of the Earth’s climate history and mechanisms.
Because glaciers are retreating rapidly worldwide, some important glaciers are now no longer scientifically viable for taking cores, and many more glacier sites will continue to be lost, the "Snows of Mount Kilimanjaro" (Hemingway) for example could be gone by 2015.
Ice core
An 'ice core' is a core sample that is typically removed from an ice sheet, most commonly from the polar ice caps of Antarctica, Greenland or from high mountain glaciers elsewhere. As the ice forms from the incremental build up of annual layers of snow, lower layers are older than upper, and an ice core contains ice formed over a range of years. The properties of the ice and the recrystallized inclusions within the ice can then be used to reconstruct a climatic record over the age range of the core, normally through isotopic analysis. This enables the reconstruction of local temperature records and the history of atmospheric composition.
Non-polar ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km (20,000 mile ), thus also known as continental glacier.
South Dome, Greenland
The South Dome at 2850 meters above sea level (masl) (, 2850 masl) of the Greenland ice sheet covers about 150,000 km and is an ice sheet probably separate from the northwest ice sheet during the Eemian interglacial period. Although it stretches to the north, the South Dome ice sheet is south of the Arctic Circle and as such is not strictly a polar ice sheet. The southern dome reaches almost 3,000 metres at latitudes 63°-65°N.
Temperatures at the crest of the south dome are about -20°C (-4°F).
The first core at South Dome used a Shallow (Swiss) drill type for a 7.6 cm diameter core to 80 m in 1975.
Dye 2
Drilling with a Shallow (Swiss) drill type at Dye 2 (, 2338 masl) began in 1973. The core is 7.6 cm in diameter to a depth of 50 m.
A second core is drilled in 1974 to 101 m at 10.2 cm in diameter.
An additional core at Dye 2 is drilled in 1977 using a Shallow (US) drill type, 7.6 cm diameter, to 84 m.
Dye 3
'Dye 3' is an ice core site and previously part of the Distant Early Warning (DEW) line, located at (, 2480 masl) in Greenland. Dye 3 has at least seven ice cores taken from various depth.
Non-polar ice cap
A 'non-polar ice cap' is an ice mass that covers less than 50,000 km of land area (usually a highland area) in the mid latitudes or tropics of a planet or natural satellite. Non-polar ice caps lie outside the arctic and antarctic circles, i.e., the polar regions.
Quelccaya Ice Cap
Although the ice cores from Quelccaya ice cap only go back ~2 ka, It is an extensive area of interconnected valley glaciers from which the higher peaks rise as nunataks. Ice fields are larger than alpine glaciers, smaller than ice sheets and similar in area to ice caps. Presently, the Earth may still be in the fifth ice age, there being numerous ice fields in the northern continental region and ice fields in New Zealand, Argentina and Chile in the southern hemisphere.
Columbia Icefield
The Columbia Icefield () is an icefield located in the Canadian Rockies, astride the Continental Divide of North America. The icefield lies partly in the northwestern tip of Banff and the southern end of Jasper National Park. It is about 325 km in area, 100 to 365 metres (328 to 1,197 ft) in depth and receives up to seven metres (275 in) of snowfall per year. The Columbia Ice Field has actually grown during the Holocene.
Flint Icefield
At least one ice core is taken from the Flint ice field (, 2290 masl) in 1982.
Mount Kilimanjaro ice field
Evidence for three periods of abrupt climate change in the Holocene climatic optimum have been recovered from six Kilimanjaro (, 5895 masl) ice cores drilled in January and February 2000.
These cores provide a ~11.7 ka record of Holocene climate and environmental variability including three periods of abrupt climate change at ~8.3, ~5.2 and ~4 ka.
Upper Fremont Glacier
Ice core samples are taken from Upper Fremont Glacier at in 1990-1991. These ice cores are analyzed for climatic changes as well as alterations of atmospheric chemicals. In 1998 an unbroken ice core sample of 164 m is taken from the glacier and subsequent analysis of the ice showed an abrupt change in the oxygen isotope ratio oxygen-18 to oxygen-16 in conjunction with the end of the Little Ice Age, a period of cooler global temperatures between the years 1550 and 1850. A linkage is established with a similar ice core study on the Quelccaya Ice Cap in Peru. This demonstrated the same changes in the oxygen isotope ratio during the same period.
The same ice cores are also tested for mercury deposition from natural and human-induced activities. This is the first known instance in which ice cores have been used to determine mercury deposition from a mid-latitude glacier in North America, as all previous studies have been derived from other sources. The majority of mercury deposition is by way of the atmosphere and sources of the element may be from volcanic activity or from industrialization, but volcanoes contribute a small proportion of the mercury. The ice core samples from the Upper Fremont Glacier indicate that levels of mercury increase dramatically during the industrial revolution and have decreased significantly since the mid 1980s. It is believed that the decrease in mercury deposition since the 1980s coincides with the passage of the Clean Air Act.
East Rongbuk Glacier
A shallow ice core drilled from the East Rongbuk glacier () showed a dramatic increasing trend of black carbon concentrations in the ice stratigraphy since the 1990s.
Schneeferner
The 'Schneeferner' () in the Bavarian Alps is Germany's highest and largest glacier. It is located on the Zugspitzplatt, a plateau south of the country's highest peak, the Zugspitze, that descends from west to east and forms the head of the Reintal valley. The meltwaters from the glacier seep away into the karstified plateau and surface again in the Reintal, where they feed the River Partnach. The Schneeferner is one of the northernmost glaciers in the Alps.The Northern Schneeferner was first described in 1820 and covers an area of 340,000 m .
Sampling of glacier ice from the Northern Schneeferner (Germany; 47°25'N, 10°59'E) in June 2005 consisted of an ice core.

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