An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper, and an ice core contains ice formed over a range of years. Cores are drilled with hand augers or powered drills; they can reach depths of over two miles (3.2 km), and contain ice up to 800,000 years old.
Dansgaard–Oeschger events are rapid climate fluctuations that occurred 25 times during the last glacial period. Some scientists say that the events occur quasi-periodically with a recurrence time being a multiple of 1,470 years, but this is debated. The comparable climate cyclicity during the Holocene is referred to as Bond events.
Willi Dansgaard was a Danish paleoclimatologist. He was Professor Emeritus of Geophysics at the University of Copenhagen and a member of the Royal Danish Academy of Science and Letters, the Royal Swedish Academy of Sciences, the Icelandic Academy of Sciences, and the Danish Geophysical Society.
Hans Oeschger was the founder of the Division of Climate and Environmental Physics at the Physics Institute of the University of Bern in 1963 and director until his retirement in 1992.
Roosevelt Island is an ice-covered island, about 130 km (81 mi) long in a NW-SE direction, 65 km (40 mi) wide and about 7,500 km2 (2,896 sq mi) in area, lying under the eastern part of the Ross Ice Shelf of Antarctica. Its central ridge rises to about 550 m (1,804 ft) above sea level, but this and all other elevations of the island are completely covered by ice, so that the island is invisible at ground level.
The Greenland ice sheet is a vast body of ice covering 1,710,000 square kilometres (660,000 sq mi), roughly 79% of the surface of Greenland.
The European Project for Ice Coring in Antarctica (EPICA) is a multinational European project for deep ice core drilling in Antarctica. Its main objective is to obtain full documentation of the climatic and atmospheric record archived in Antarctic ice by drilling and analyzing two ice cores and comparing these with their Greenland counterparts. Evaluation of these records will provide information about the natural climate variability and mechanisms of rapid climatic changes during the last glacial epoch.
The Greenland Ice Core Project (GRIP) was a multinational European research project, organized through the European Science Foundation. Funding came from 8 nations, and from the European Union.
The drilling site of the North Greenland Ice Core Project is near the center of Greenland. Drilling began in 1999 and was completed at bedrock in 2003. The cores are cylinders of ice 11 centimeters in diameter that were brought to the surface in 3.5-meter lengths. The NGRIP site was chosen to extract a long and undisturbed record stretching into the last glacial, and it succeeded. The site was chosen for a flat basal topography to avoid the flow distortions that render the bottom of the GRIP and GISP cores unreliable. Unusually, there is melting at the bottom of the NGRIP core - believed to be due to a high geothermal heat flux locally. This has the advantage that the bottom layers are less compressed by thinning than they would otherwise be: NGRIP annual layers at 105 kyr age are 1.1 cm thick, twice the GRIP thicknesses at equal age.
An abrupt climate change occurs when the climate system is forced to transition to a new climate state at a rate that is determined by the climate system energy-balance, and which is more rapid than the rate of change of the external forcing. Past events include the end of the Carboniferous Rainforest Collapse, Younger Dryas, Dansgaard-Oeschger events, Heinrich events and possibly also the Paleocene–Eocene Thermal Maximum. The term is also used within the context of global warming to describe sudden climate change that is detectable over the time-scale of a human lifetime, possibly as the result of feedback loops within the climate system.
Dome Fuji, also called Dome F or Valkyrie Dome, is an Antarctic base located in the eastern part of Queen Maud Land at 77°30′S37°30′E. With an altitude of 3,810 m or 12,500 ft above sea level, it is the second-highest summit or ice dome of the East Antarctic ice sheet and represents an ice divide. Dome F is the site of Dome Fuji Station, a research station operated by Japan.
Dye 3 is an ice core site and previously part of the Distant Early Warning (DEW) line, located at in Greenland. As a DEW line base, it was disbanded in years 1990/1991.
Camp Century was an Arctic United States military scientific research base in Greenland. situated 150 miles east of Thule Air Base. When built, Camp Century was publicized as a demonstration for affordable ice-cap military outposts and a base for scientific research.
Summit Camp, also Summit Station, is a year-round research station on the apex of the Greenland Ice Sheet. Its coordinates are variable, since the ice is moving. The coordinates provided here are as of July 2009. The station is located 3,216 metres (10,551 ft) above sea level. The population of the station is typically five in wintertime, and has a maximum of 38 in the summer. The station is operated by the United States' National Science Foundation through the logistical support contractorBattelle Arctic Research Operations. A permit from the Danish Polar Center under the auspices of the Home Rule Government of Greenland is required to visit the station.
NEEM Camp was a small research facility on the northern Greenland Ice Sheet, used as a base for ice core drilling. It is located about 313 km east of the closest coast, Peabody Bay in northern Greenland, 275 km northwest of the historical ice sheet camp North Ice, and 484 km east-northeast of Siorapaluk, the closest settlement. There is only one heavy-duty tent for accommodation of the researchers during summer. Access is by skiway .
Ice drilling allows scientists studying glaciers and ice sheets to gain access to what is beneath the ice, to take measurements along the interior of the ice, and to retrieve samples. Instruments can be placed in the drilled holes to record temperature, pressure, speed, direction of movement, and for other scientific research, such as neutrino detection.
Herbert T. Ueda was a retired American ice drilling engineer.
Scientific ice drilling began in 1840, when Louis Agassiz attempted to drill through the Unteraargletscher in the Alps. Rotary drills were first used to drill in ice in the 1890s, and thermal drilling, with a heated drillhead, began to be used in the 1940s. Ice coring began in the 1950s, with the International Geophysical Year at the end of the decade bringing increased ice drilling activity. In 1966, the Greenland ice sheet was penetrated for the first time with a 1,388 m hole reaching bedrock, using a combination of thermal and electromechanical drilling. Major projects over the following decades brought cores from deep holes in the Greenland and Antarctic ice sheets.
Pavel Grigorievich Talalay, is a Russian Professor of drilling engineering and director of the Polar Institute for Polar Science and Engineering in Jilin University, Changchun, China. His research interests are focused on different features of drilling technology in ice and permafrost; dynamics of ice sheets; ice properties and environmental issues in Polar Regions.
