Mass Balance and Accumulation Rate Along US ITASE Routes

US ITASE 航线沿线的质量平衡和累积率

• 批准号: 9815110
• 负责人: Gordon Hamilton
• 金额: --
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2001-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9815110&HistoricalAwards=false
• 关键词: Mass; Balance; Accumulation; Rate; Along

This award provides support for five years of funding to determine the mass balance and accumulation rate of ice along the traverse routes of the U.S. International Trans-Antarctic Scientific Expedition (US ITASE) program. The rate of ice sheet thickening or thinning will be measured along flow lines, along ice divides and along elevation contours in West Antarctica using a method which measures the vertical velocities of markers buried in subsurface ice. This method uses the Global Positioning System (GPS) and surveying techniques to determine the precise location of these markers. Vertical velocities so obtained are compared with long-term rates of snow accumulation and the difference in the two is a measure of ice sheet thickness change. A series of recording instruments will be installed to provide continuous records of firn densification and snow surface elevation change. These instruments will be deployed at selected sites to link transient changes in snow surface elevation, as measured by altimeters, to long-term rates of ice thickness change. Ice motion at drill sites, upglacier topography and upglacier gradients in accumulation rate will be measured and used to calculate ice flow-induced accumulation rate variations and remove them from the ice core records. This work will provide the capability to deduce true past climatic variations in accumulation rate from the US ITASE ice core records.

该奖项为确定美国国际跨南极科学考察(US ITASE)计划横贯路线上冰的质量平衡和积累率的五年资金提供支持。将使用一种测量埋藏在地下冰中的标记物的垂直速度的方法，测量南极洲西部的冰盖增厚或变薄的速度，这些速度将沿着流线、冰区和海拔等高线进行测量。这种方法使用全球定位系统(GPS)和测量技术来确定这些标记的精确位置。将获得的垂直速度与长期积雪速度进行比较，两者之间的差异是冰盖厚度变化的衡量标准。将安装一系列记录仪器，以提供积雪密实度和雪面海拔变化的连续记录。这些仪器将部署在选定的地点，将高度计测量的雪面高度的瞬时变化与冰层厚度的长期变化率联系起来。将测量钻探地点的冰运动、冰川上地形和上冰川堆积速率梯度，并用于计算冰流引起的堆积速率变化，并将它们从冰芯记录中删除。这项工作将提供从美国ITASE冰芯记录中推断过去真实的气候累积速率变化的能力。