Collaborative Research: The demise of the world's largest piedmont glacier

合作研究：世界上最大的山麓冰川的消亡

• 批准号: 1929718
• 负责人: Douglas Brinkerhoff
• 金额: $ 30.06万
• 依托单位: University of Montana
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1929718&HistoricalAwards=false
• 关键词: Collaborative; Research; demise; world; largest

Located on the coast of Southeast Alaska, Malaspina Glacier is the world’s largest piedmont glacier, a type of glacier that starts in the mountains and spills out onto the coastal plain. The Malaspina Glacier is currently rapidly thinning and retreating, forming a series of proglacial lakes along the bottom edge. Some of these lakes are only separated from the open ocean by a narrow band of sediment moraine. The underside of the glacier is located well below sea level and all current indications are that retreat and thinning will continue, and most likely accelerate, even with little future climate change. This has the potential to be the largest loss of ice in Alaska from one glacier in the next several decades. As the Malaspina Glacier retreats and thins it will transform the landscape, exposing more rocks and moraine, creating new lakes, and/or leading to significant changes in the coastline, such as the formation of marine fjords. If this happens, it will be one of the largest modern changes to Alaska’s and the nation’s coastline with large impacts to both terrestrial and marine ecosystems. These changes would also constitute the largest single change in terrestrial land cover in the National Park system in recent history.The main goal of this work is to use a computer model to estimate what the future could look like for the Malaspina Glacier and surrounding area. Measurements collected in the field, on and around the glacier, will provide the necessary model input data. The work will result in a comprehensive data set on glacier mass balance, ice velocity, ice thickness, glacier bed conditions, surface debris extent and thickness, proglacial lake development, and proglacial thermokarst evolution. These data will be ingested into a numerical model that will be used to explore a large range of possible future scenarios for the evolution of Malaspina Glacier. The model scenarios will account for different climate trajectories as well as uncertainties of model parameters, such as those associated with hydrology and motion at the underside of the glacier. Specifically, the following questions will be addressed:1. Is a pathway from the ocean to the glacier front critical for catastrophic retreat?2. Will the retreat of Malaspina be dominated by surface mass balance?3. What are the main uncertainties for model predictions?This work will lead to a better understanding of how climate change interacts with dynamic instabilities that are independent of climate, in an area that has historically been characterized by large glacier fluctuations and spatial and temporal variability. While dynamically caused retreats are common for coastal glaciers, these effects are amplified in the presence of ongoing warming.Malaspina Glacier is located in the Wrangell-St. Elias National Park and has the potential to help people envision the potentially dramatic effects of climate change on the Earth’s cryosphere. A graphic artist will convert the model results into striking visuals that show the opening up of a new landscape. Using an online message testing experiment, the project will test and develop outreach materials to increase visitor knowledge of ongoing and anticipated future glacier change and climate change. Visuals and associated information will become interactive exhibits that will engage thousands of visitors at the Wrangell-St. Elias National Park visitor center and online. In addition, this project will train three graduate students in relevant geophysical techniques, modern ice sheet modeling approaches, and collaborative research. The project outcomes will be published in peer-reviewed literature and presented at professional meetings.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

马拉斯皮纳冰川位于阿拉斯加东南部海岸，是世界上最大的皮埃蒙特冰川，一种始于山区并溢出到沿海平原的冰川。马拉斯皮纳冰川目前正在迅速变薄和退缩，形成了一系列的冰前湖沿着底部边缘。这些湖泊中的一些只是通过一条狭窄的沉积物冰碛带与开阔的海洋隔开。冰川的底部位于海平面以下，目前的所有迹象表明，即使未来气候变化不大，退缩和变薄仍将继续，而且很可能加速。这有可能是阿拉斯加在未来几十年内从一个冰川中损失的最大冰。随着马拉斯皮纳冰川的退缩和变薄，它将改变景观，暴露出更多的岩石和冰碛，创造新的湖泊，和/或导致海岸线的重大变化，如海洋峡湾的形成。如果发生这种情况，这将是阿拉斯加和全国海岸线最大的现代变化之一，对陆地和海洋生态系统都有很大的影响。这些变化也将构成国家公园系统陆地覆盖物在近代历史上最大的单一变化。这项工作的主要目标是使用计算机模型来估计马拉斯皮纳冰川和周围地区的未来可能是什么样子。在冰川上和周围的实地收集的测量数据将提供必要的模型输入数据。这项工作将产生一套关于冰川物质平衡、冰速、冰厚、冰川床状况、表面碎片范围和厚度、冰前湖泊发展和冰前热岩溶演化的综合数据。这些数据将被纳入一个数值模型，该模型将用于探索马拉斯皮纳冰川演变的大范围可能的未来情景。模型情景将考虑不同的气候轨迹以及模型参数的不确定性，例如与冰川底部水文和运动有关的参数。具体而言，将解决以下问题：1。从海洋到冰川前沿的路径是灾难性退缩的关键吗？2.马拉斯皮纳的撤退会受到地表物质平衡的支配吗？3.模型预测的主要不确定性是什么？这项工作将有助于更好地了解气候变化如何与独立于气候的动态不稳定性相互作用，在一个历史上以大冰川波动和时空变异为特征的地区。虽然动态引起的退缩对沿海冰川来说很常见，但在持续变暖的情况下，这些影响会被放大。马拉斯皮纳冰川位于兰格尔-圣埃利亚斯国家公园，有可能帮助人们想象气候变化对地球冰冻圈的潜在巨大影响。一位平面艺术家将把模型结果转换成引人注目的视觉效果，展示一个新景观的开放。该项目将利用在线信息测试实验，测试和编写宣传材料，以增加游客对当前和预期未来冰川变化和气候变化的了解。视觉和相关信息将成为互动展览，将吸引成千上万的游客在兰格尔圣埃利亚斯国家公园游客中心和在线。此外，该项目还将培训三名研究生掌握相关的地球物理技术、现代冰盖建模方法和合作研究。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。