NSFGEO-NERC: Ice-shelf Instability Caused by Active Surface Meltwater Production, Movement, Ponding and Hydrofracture

NSFGEO-NERC：活跃地表融水产生、移动、积水和水力压裂导致的冰架不稳定

• 批准号: 1841467
• 负责人: Douglas MacAyeal
• 金额: $ 14.41万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1841467&HistoricalAwards=false
• 关键词: NSFGEO; NERC; Ice; shelf; Instability

The evolution of surface and shallow subsurface meltwater across Antarctic ice shelves has important implications for their (in)stability, as demonstrated by the 2002 rapid collapse of the Larsen B Ice Shelf. It is vital to understand the causes of ice-shelf (in)stability because ice shelves buttress against the discharge of inland ice and therefore influence ice-sheet contributions to sea-level rise. Ice-shelf break-up may be triggered by stress variations associated with surface meltwater movement, ponding, and drainage. These variations may cause an ice shelf to flex and fracture. This four-year project will provide key geophysical observations to improve understanding of ice-shelf meltwater and its effects on (in)stability. The work will be conducted on the George VI Ice Shelf on the Antarctic Peninsula, where hundreds of surface lakes form each summer. Over a 27-month period, global positioning systems, seismometers, water pressure transducers, automatic weather stations, and in-ice thermistor strings will be deployed to record ice shelf flexure, fracture seismicity, water depths, and surface and subsurface melting, respectively, in and around several surface lakes on the George VI Ice Shelf, within roughly 20 km of the British Antarctic Survey's Fossil Bluff Station. Field data will be used to validate and extend the team's approach to modelling ice-shelf flexure and stress, and possible "Larsen-B style" ice-shelf instability and break-up.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.

南极冰架表面和浅层地下融水的演变对其稳定性（不稳定）具有重要影响，2002 年拉森 B 冰架的快速崩塌就证明了这一点。了解冰架稳定性（不稳定）的原因至关重要，因为冰架支撑内陆冰的排放，从而影响冰盖对海平面上升的贡献。冰架破裂可能是由与地表融水运动、积水和排水相关的应力变化引发的。 这些变化可能会导致冰架弯曲和断裂。这个为期四年的项目将提供关键的地球物理观测，以增进对冰架融水及其对稳定性影响的了解。 这项工作将在南极半岛的乔治六世冰架上进行，那里每年夏天都会形成数百个地表湖泊。在 27 个月的时间内，将部署全球定位系统、地震仪、水压传感器、自动气象站和冰内热敏电阻串，分别记录冰架弯曲、断裂地震活动、水深以及地表和地下融化，乔治六世冰架上的几个表层湖泊及其周围，距离英国南极调查局化石崖站约 20 公里。现场数据将用于验证和扩展团队模拟冰架弯曲和应力以及可能的“拉森-B 型”冰架不稳定和破裂的方法。该奖项反映了 NSF 的法定使命，并被认为是值得的通过使用基金会的智力优势和更广泛的影响审查标准进行评估来提供支持。

项目成果

Treatment of ice-shelf evolution combining flow and flexure

结合流动和弯曲处理冰架演化

• DOI: 10.1017/jog.2021.39
• 发表时间: 2021-10
• 期刊: Journal of Glaciology
• 影响因子: 3.4
• 作者: MacAyeal, Douglas R.;Sergienko, Olga V.;Banwell, Alison F.;Macdonald, Grant J.;Willis, Ian C.;Stevens, Laura A.
• 通讯作者: Stevens, Laura A.

Enigmatic surface rolls of the Ellesmere Ice Shelf

埃尔斯米尔冰架神秘的表面滚动

• DOI: 10.1017/jog.2022.3
• 发表时间: 2022-01
• 期刊: Journal of Glaciology
• 影响因子: 3.4
• 作者: Coffey, Niall B.;MacAyeal, Douglas R.;Copland, Luke;Mueller, Derek R.;Sergienko, Olga V.;Banwell, Alison F.;Lai, Ching
• 通讯作者: Lai, Ching

Formation of sea ice ponds from ice-shelf runoff, adjacent to the McMurdo Ice Shelf, Antarctica

南极洲麦克默多冰架附近的冰架径流形成的海冰池

• DOI: 10.1017/aog.2020.9
• 发表时间: 2020-09
• 期刊: Annals of Glaciology
• 影响因子: 2.9
• 作者: Macdonald, Grant J.;Popović, Predrag;Mayer, David P.
• 通讯作者: Mayer, David P.

Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica

南极洲麦克默多冰架上基座遗迹湖的形成

• DOI: 10.1017/jog.2019.17
• 发表时间: 2019-04
• 期刊: Journal of Glaciology
• 影响因子: 3.4
• 作者: MACDONALD, GRANT J.;BANWELL, ALISON F.;WILLIS, IAN C.;MAYER, DAVID P.;GOODSELL, BECKY;MacAYEAL, DOUGLAS R.
• 通讯作者: MacAYEAL, DOUGLAS R.