Quantifying Surface Processes above Buried Ice in Antarctica: Implications for Terrestrial Climate Change and Glaciation on Mars

量化南极洲埋冰上方的表面过程：对陆地气候变化和火星冰川作用的影响

• 批准号: 0944702
• 负责人: David Marchant
• 金额: $ 11.56万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0944702&HistoricalAwards=false
• 关键词: Quantifying; Surface; Processes; above; Buried

Intellectual Merit: The recognition that Pliocene and Miocene age glacier ice lies buried beneath sublimation tills in the coldest parts of the Dry Valleys, and likely elsewhere in the Transantarctic Mountains, opens up the possibility of establishing multi-million year records of climate and atmospheric evolution. The PI proposes a quantitative analysis of the Mullins Glacier, the oldest debris-covered alpine glacier. Preliminary work suggests that ancient atmosphere is trapped within Mullins Glacier, however, geomorphic processes, have modified the glacier in unforeseen ways. In prior work, the PI developed qualitative models defining these processes, and in this proposal he seeks to quantify and test these models through quantitative modeling and higher-level data acquisition. Questions to be addressed include: What aspects of vapor diffusion, atmosphere-surface interactions, and till characteristics encourage long-term preservation of buried ice? How might sublimation tills and sublimation polygons at the ice surface influence subsurface ice loss and the composition of trapped gases in glacier ice? Do morphometric parameters of sublimation polygons shed light on the depth and purity of subsurface ice? If so, can these morphometric parameters be used to map undetected buried-ice deposits elsewhere on Earth and Mars? What can variations in the concentration/ style englacial debris in Mullins Glacier tell us about local environmental change over multi-million year old time scales? To answer these questions, the PI proposes numerous experiments for Mullins Glacier.Broader impacts: This work will quantify surface processes that modify what may be the longest record of atmospheric evolution and climate change. This research has relevance for understanding buried ice on Mars. The research will support a graduate student and undergraduates. The PI will continue his successful outreach activities with the Los Angeles Valley Community College system and in further developing his digital image analyses lab at Boston University, which showcases his Antarctic and planetary work in 3D to visiting students, faculty, parents, and those interested in Antarctica in the wider community.

智力优点：认识到上新世和中新世冰川冰埋藏在干谷最冷地区的升华碓下，很可能在横贯南极山脉的其他地方，这为建立数百万年的气候和大气演化记录提供了可能性。 PI 提议对马林斯冰川（最古老的被碎片覆盖的高山冰川）进行定量分析。初步研究表明，古代大气被困在马林斯冰川内，然而，地貌过程以不可预见的方式改变了冰川。在之前的工作中，PI 开发了定义这些过程的定性模型，在本提案中，他寻求通过定量建模和更高级别的数据采集来量化和测试这些模型。需要解决的问题包括：蒸汽扩散、大气-地表相互作用以及冰斗特性的哪些方面促进埋冰的长期保存？冰表面的升华物和升华多边形如何影响地下冰损失和冰川冰中滞留气体的成分？升华多边形的形态参数能否揭示地下冰的深度和纯度？如果是这样，这些形态测量参数是否可以用于绘制地球和火星其他地方未发现的埋冰沉积物的地图？马林斯冰川中冰川碎片浓度/类型的变化可以告诉我们什么关于数百万年时间尺度上当地环境变化的信息？为了回答这些问题，PI 提出了针对马林斯冰川的大量实验。更广泛的影响：这项工作将量化地表过程，这些过程可能会改变大气演化和气候变化的最长记录。这项研究对于了解火星上埋藏的冰具有相关性。该研究将为研究生和本科生提供支持。该 PI 将继续在洛杉矶谷社区学院系统中开展成功的外展活动，并进一步开发他在波士顿大学的数字图像分析实验室，该实验室以 3D 方式向来访的学生、教师、家长和更广泛的社区中对南极洲感兴趣的人们展示他的南极和行星工作。