Deglaciation of the Marble Hills, Southern Ellsworth Mountains

南埃尔斯沃斯山脉大理石山冰川消融

• 批准号: 0230198
• 负责人: John Stone
• 金额: $ 5.57万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0230198&HistoricalAwards=false
• 关键词: Deglaciation; Marble; Hills; Southern; Ellsworth

This award supports a project to date a series of samples that were collected during some reconnaissance fieldwork in the Marble Hills, at the southern end of the Ellsworth Mountains, where the WAIS flows into the head of the Ronne- Filchner Ice Shelf. These glacial erratic samples cover a range of altitudes up to 500 m above the present ice surface and are mostly faceted till stones that were stranded as overriding, glacial-maximum ice retreated from the highest point in the Marble Hills to its present level. The samples will be dated with cosmogenic 10 Be, allowing us to obtain a preliminary thinning history for this largely unconstrained sector of the ice sheet. The results will provide the first numerical dating control on the history of the WAIS in the Weddell Sea region since the last glacial maximum. This new data will constrain ice sheet reconstructions, which up to now have been based heavily on geomorphological observations lacking age control, in the Ellsworth Mountains. The results will complement marine geophysical constraints on the expansion of grounded ice into the Weddell Sea during the glacial maximum, and mapping and dating of ice limits along the northern coasts of the Weddell Sea. The exposure ages from the Marble Hills will provide an interesting comparison with reconstructions of the time-course of Holocene deglaciation in the Ross Sea and in Marie Byrd Land. Because of differences in climate, bathymetry, and bed characteristics between these regions, comparison of their deglaciation histories will provide insight into the dynamics of the ice sheet, and perhaps help to explain the prolonged WAIS retreat in and around the Ross Sea. The Weddell Sea is also an important site of Antarctic Bottom Water (AABW) formation, and it may act as an important link between the WAIS and the global climate system. Because an expanded ice sheet in the Weddell Sea would have altered the distribution of AABW production, knowing the timing of deglaciation is important for understanding the establishment of present-day patterns of ocean circulation.

该奖项支持了一个项目，即在埃尔斯沃思山脉（Ellsworth Mountains）南端的大理石山（Marble Hills）的一些侦察现场工作中收集的一系列样品，那里的wais流入了罗恩·菲尔奇纳（Ronne-Filchner）冰架的头部。 这些冰川不稳定的样品覆盖了当前冰表面高达500 m的一系列高度，并且大部分被刻在石头上，直到石头被搁浅，冰川最大的冰冰从大理石山的最高点撤退到当前水平。样品将以宇宙基础10的方式进行日期，从而使我们能够为冰盖的这一不受限制的部门获得初步的稀疏病史。结果将提供对自上次冰川最大值以来Weddell Sea地区病史的第一个数值约会控制。这些新数据将限制冰盖的重建，到目前为止，这些重建基于Ellsworth山区缺乏年龄控制的地貌观察。 结果将补充海洋地球物理限制在冰川最大值期间接地冰扩展到韦德尔海的情况，以及在韦德尔海北部海岸沿冰极限的地图和约会。大理石丘陵的暴露年龄将与罗斯海和玛丽·伯德（Marie Byrd Land）的全新世脱离时期的重建进行有趣的比较。由于这些区域之间的气候，测深和床特征的差异，其脱气历史的比较将为冰盖的动力学提供洞察力，并可能有助于解释罗斯海和周围的长时间的WAIS静修。韦德尔海也是南极底水（AABW）地层的重要地点，它可能充当WAIS与全球气候系统之间的重要联系。因为在韦德尔海扩大的冰盖将改变AABW生产的分布，因此知道脱气的时机对于理解当今海洋循环模式的建立很重要。