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The West Antarctic Ice Sheet (WAIS) Divide is a deep ice core drilling project run by the United States Antarctic Program (USAP) and funded by the National Science Foundation (NSF). The general purpose of the WAIS Divide project is to collect a deep ice core from the flow divide in the central West Antarctic Ice Sheet that can be used for scientific analysis and research. Specifically, scientists are looking to create the largest and most detailed record of greenhouse gases possible for the last 100,000 years, and also plan to look at the role climate change could have had on these amounts.〔(WAIS Divide Ice Core Project )〕 ==History== The WAIS Divide project began during the 2005/2006 field season when the first team of Antarctic Support Contract staff established the seasonal field camp and began construction on the ice core handling and processing facility. During this first season, Scientists dug a few shallow ice cores to test out the site. Over the 2006/2007 season, work continued on the arch handing and processing facility, as well as set up for the eventual Deep Ice Sheet Coring (DISC) drill. At the end of the 2009/2010 field season, the project had reached a depth of 2,564 meters, with a targeted depth of about 3,330 meters, about 100 meters above bedrock.〔(Core Truths )〕 The WAIS Divide project will begin its 2010/2011 field season in November 2010, with the goal of reaching the target depth.〔(Core Truths )〕 Additional work is planned for two more seasons beyond that, including borehole analysis and replicate coring.〔(Core Truths )〕 == Site selection == In order to get the necessary types of ice core samples for successful research, scientists sought out an area of the Antarctic Continent that would be the most beneficial. The WAIS Divide was chosen because of the relative smoothness of the bed topography, the fact that the internal layers of ice are flat and undisturbed, and that the annual layers, each about 1 cm thick, will be detectable to at least 40,000 years within the ice sheet. Also significant is the fact that at the WAIS Divide, there is minimal horizontal ice flow, which guarantees more accurate data due to the ability to pin-point the specific atmospheric conditions in the same location as the ice sheet. One last important fact about the WAIS Divide location is the significance that the gas-age to ice-age difference is about 200 years for the Holocene epoch, and about 300 to 500 years for the last glacial period.〔(Site info )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「WAIS Divide」の詳細全文を読む スポンサード リンク
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