Greenland Ice Sheet Project
Encyclopedia
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...
s in Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
that involved scientist
Scientist
A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...
s and funding agencies from Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
, Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
and the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. Besides the U.S. National Science Foundation
National Science Foundation
The National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...
, funding was provided by the Swiss National Science Foundation
Swiss National Science Foundation
The Swiss National Science Foundation is a science research support organization mandated by the Swiss Federal Government. The SNSF was established in 1952 as a foundation under private law. Its secretariat is based in Bern....
and the Danish Commission for Scientific Research in Greenland. The ice cores provide a proxy
Proxy (climate)
In the study of past climates is known as paleoclimatology, climate proxies are preserved physical characteristics of the past that stand in for direct measurements , to enable scientists to reconstruct the climatic conditions that prevailed during much of the Earth's history...
archive of temperature and atmospheric constituents that help to understand past climate variations.
The preliminary GISP field work started in 1971 at Dye 3
Dye 3
Dye 3 is an ice core site and previously part of the Distant Early Warning line, located at in Greenland. As a DEW line base, it was disbanded in years 1990/1991....
(65°N 43°W), where a 372 meter deep, 10.2 cm diameter core was recovered. After this, annual field expeditions were carried out to drill intermediate depth cores at various locations on the ice sheet
Ice sheet
An ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² , thus also known as continental glacier...
. The first was a 398 m core at Milcent and another was a 405 m core at the Crete station in 1974. After working out various logistical
Logistics
Logistics is the management of the flow of goods between the point of origin and the point of destination in order to meet the requirements of customers or corporations. Logistics involves the integration of information, transportation, inventory, warehousing, material handling, and packaging, and...
and engineering
Engineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...
problems related to the development of a more sophisticated drilling rig
Drilling rig
A drilling rig is a machine which creates holes or shafts in the ground. Drilling rigs can be massive structures housing equipment used to drill water wells, oil wells, or natural gas extraction wells, or they can be small enough to be moved manually by one person...
, drilling to bedrock
Bedrock
In stratigraphy, bedrock is the native consolidated rock underlying the surface of a terrestrial planet, usually the Earth. Above the bedrock is usually an area of broken and weathered unconsolidated rock in the basal subsoil...
at Dye 3 began in the summer of 1979 using a new Danish electro-mechanical ice drill. In the first year, an 18 cm diameter hole was drilled and cased to a depth of 80 m. Coring continued for two more seasons, and on August 10, 1981, bedrock was reached at a depth of 2037 m. The Dye 3 site was a compromise: glaciologically
Glaciology
Glaciology Glaciology Glaciology (from Middle French dialect (Franco-Provençal): glace, "ice"; or Latin: glacies, "frost, ice"; and Greek: λόγος, logos, "speech" lit...
, a higher site on the ice divide
Ice divide
An ice divide is the boundary on an ice sheet, ice cap or glacier separating opposing flow directions of ice, analogous to a water divide. Such ice divides are important for geochronology investigations using ice cores, because such coring is typically made on top of a dome of an ice sheet to avoid...
with smooth bedrock would have been better; logistically, such a site would have been too remote.
GISP2
There was a follow-up U.S. GISP2 project, which drilled at a glaciologically better location on the summit of the ice sheet. This hit bedrock (and drilled another 1.55 m into bedrock) on July 1, 1993 after five years of drilling, while EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
an scientists produced a parallel core in the GRIP
Greenland ice core project
The Greenland Ice Core Project was a multinational European research project, organised through the European Science Foundation. Funding came from 8 nations , and from the European Union...
project. GISP2 produced an ice core 3053.44 meters in depth, the deepest ice core recovered in the world at the time.
The location of the GISP2 drilling was revisited annually during summer campaigns to investigate the post-depositional properties of gasses and aerosols in the firn
Firn
Firn is partially-compacted névé, a type of snow that has been left over from past seasons and has been recrystallized into a substance denser than névé. It is ice that is at an intermediate stage between snow and glacial ice...
. Eventually, GISP2 and Summit Camp
Summit Camp
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 3216 meters above sea level...
became the site of a year round NSF / NOAA climate observatory and research facility known as the Greenland Environmental Observatory or GEOSummit.
The bulk of the GISP2 ice core is archived at the National Ice Core Laboratory
National Ice Core Laboratory
The National Ice Core Laboratory located at the Denver Federal Center is the primary repository for ice cores collected by the United States. The facility is managed by the United States Geological Survey , and jointly funded by the USGS, National Science Foundation, and the University of New...
in Lakewood, Colorado
Lakewood, Colorado
Lakewood is a Home Rule Municipality that is the most populous city in Jefferson County, Colorado, United States. Lakewood is the fifth most populous city in the State of Colorado and the 172nd most populous city in the United States. The United States Census Bureau estimates that in April 1, 2010...
, United States.
See also
- Clair Patterson
- Dye 3Dye 3Dye 3 is an ice core site and previously part of the Distant Early Warning line, located at in Greenland. As a DEW line base, it was disbanded in years 1990/1991....
- EPICAEPICAThe European Project for Ice Coring in Antarctica 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...
- Greenland ice cores
- North Greenland Ice Core Project (NGRIP)
External links
- GISP from the NOAANational Oceanic and Atmospheric AdministrationThe National Oceanic and Atmospheric Administration , pronounced , like "noah", is a scientific agency within the United States Department of Commerce focused on the conditions of the oceans and the atmosphere...
World Data CenterWorld Data CenterThe World Data Center system was created to archive and distribute data collected from the observational programs of the 1957-1958 International Geophysical Year. Originally established in the United States, Europe, Soviet Union, and Japan, the WDC system has since expanded to other countries and...
for paleoclimatology - GISP2