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

学术价值：认识到上新世和中新世的冰川冰埋藏在干谷最冷地区的升华山丘下，很可能在南极横贯山脉的其他地方，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提出了对马林斯冰川的定量分析，这是最古老的高山冰川。初步研究表明，古代大气被困在马林斯冰川中，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，而在本提案中，他试图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。要解决的问题包括：蒸汽扩散、大气表面相互作用和土壤特征的哪些方面鼓励埋藏冰的长期保存？冰表面的升华丘和升华多边形如何影响地下冰的损失和冰川冰中被困气体的组成？升华多边形的形态参数是否揭示了地下冰的深度和纯度？如果是这样的话，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被发现的埋藏冰沉积物？穆林斯冰川中冰川碎片的浓度/样式的变化能告诉我们几百万年前当地环境的变化吗？为了回答这些问题，PI提出了许多关于马林斯冰川的实验。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变和气候变化的最长记录。这项研究与了解火星上埋藏的冰有关。这项研究将支持一名研究生和本科生。PI将继续他与洛杉矶谷社区学院系统的成功推广活动，并进一步发展他在波士顿大学的数字图像分析实验室，向访问的学生，教师，家长和对南极洲感兴趣的人展示他的南极和行星3D工作。

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.