| 词条 | Greenland Ice Sheet Project | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 释义 |
The Greenland Ice Sheet Project (GISP) was a decade-long project to drill ice cores in Greenland that involved scientists and funding agencies from Denmark, Switzerland and the United States. Besides the U.S. National Science Foundation (NSF), funding was provided by the Swiss National Science Foundation and the Danish Commission for Scientific Research in Greenland. The ice cores provide a proxy archive of temperature and atmospheric constituents that help to understand past climate variations. The preliminary GISP field work started in 1971 at Dye 3 ({{coord|65|N|43|W|name=Dye 3}}), 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. 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 and engineering problems related to the development of a more sophisticated drilling rig, drilling to bedrock at Dye 3 began in the summer{{When|date=February 2011}} 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, a higher site on the ice divide with smooth bedrock would have been better; logistically, such a site would have been too remote. GISP drilling operations
GISP2There 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 European scientists produced a parallel core in the GRIP project. GISP2 produced an ice core 3053.44 meters in depth, the deepest ice core recovered in the world at the time.[4] 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. Eventually, GISP2 and Summit Camp became the site of a year-round NSF / NOAA climate observatory and research facility known as the Greenland Environmental Observatory or GEOSummit.[5] The bulk of the GISP2 ice core is archived at the National Ice Core Laboratory in Lakewood, Colorado, United States. {{wide image|GISP2D1837 crop.jpg|1000px|Photograph of a section of the GISP2 ice core from 1837 m depth with clearly visible annual layers.}}{{clear}}See also
References1. ^1 Langway et al. (1985), p. 3. 2. ^1 2 Langway (2008), p. 28. 3. ^Talalay (2016), p. 80. 4. ^The GISP2 Ice Coring Effort, National Climatic Data Center 5. ^NSF's Summit Greenland Observatory Sources
External links
3 : Geochronological institutions and organizations|Arctic research|Climate of Greenland |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。