Mechanisms for upstream migration of firn aquifer drainage: preliminary observations from Helheim Glacier, Greenland
Surface meltwater can influence subglacial hydrology and ice dynamics if it reaches ice sheet's base. Firn aquifers store meltwater and drain into wide crevasses marking the aquifer's downstream boundary, indicating water from firn aquifers can drive hydrofracture to establish surface-to-b...
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Cambridge University Press
2025-01-01
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| Series: | Journal of Glaciology |
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| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143024000789/type/journal_article |
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| author | Jessica Z. Mejia Kristin Poinar Colin R. Meyer Aleah N. Sommers Winnie Chu |
| author_facet | Jessica Z. Mejia Kristin Poinar Colin R. Meyer Aleah N. Sommers Winnie Chu |
| author_sort | Jessica Z. Mejia |
| collection | DOAJ |
| description | Surface meltwater can influence subglacial hydrology and ice dynamics if it reaches ice sheet's base. Firn aquifers store meltwater and drain into wide crevasses marking the aquifer's downstream boundary, indicating water from firn aquifers can drive hydrofracture to establish surface-to-bed hydraulic connections at inland locations. Yet, sparse observations limit our understanding of the physical processes controlling firn aquifer drainage. We assess the potential for future inland firn aquifer drainage migration with field observations and linear elastic fracture mechanics (LEFMs) modeling to determine the conditions needed to initiate and sustain hydrofracture on Helheim Glacier, Greenland. We find that local stress conditions alone can drive crevasse tips into the firn aquifer, allowing hydrofracture initiation year-round. We infer inland expansion of crevasses over the firn aquifer from crevasse-nucleated whaleback dune formation and Global Navigation Satellite System-station detected crevasse opening extending 14 and 4 km, respectively, inland from the current, farthest-upstream drainage point. Using our LEFM model, we identify three vulnerable regions with coincidence between dry crevasse depth and water table variability, indicating potential future inland firn aquifer drainage sites. These results suggest the downstream boundary of firn aquifers can migrate inland under future warming scenarios and may already be underway. |
| format | Article |
| id | doaj-art-51f209f294be425e8ca1ba28ab90c68d |
| institution | Kabale University |
| issn | 0022-1430 1727-5652 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj-art-51f209f294be425e8ca1ba28ab90c68d2025-01-16T21:53:05ZengCambridge University PressJournal of Glaciology0022-14301727-56522025-01-017110.1017/jog.2024.78Mechanisms for upstream migration of firn aquifer drainage: preliminary observations from Helheim Glacier, GreenlandJessica Z. Mejia0https://orcid.org/0000-0002-5489-4711Kristin Poinar1Colin R. Meyer2Aleah N. Sommers3https://orcid.org/0000-0001-8718-0603Winnie Chu4Department of Earth and Environmental Sciences, Syracuse University, Syracuse, NY, USA Department of Geology, University at Buffalo, Buffalo, NY, USADepartment of Geology, University at Buffalo, Buffalo, NY, USA RENEW Institute, University at Buffalo, Buffalo, NY, USAThayer School of Engineering, Dartmouth College, Hanover, NH, USAThayer School of Engineering, Dartmouth College, Hanover, NH, USASchool of Earth & Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USASurface meltwater can influence subglacial hydrology and ice dynamics if it reaches ice sheet's base. Firn aquifers store meltwater and drain into wide crevasses marking the aquifer's downstream boundary, indicating water from firn aquifers can drive hydrofracture to establish surface-to-bed hydraulic connections at inland locations. Yet, sparse observations limit our understanding of the physical processes controlling firn aquifer drainage. We assess the potential for future inland firn aquifer drainage migration with field observations and linear elastic fracture mechanics (LEFMs) modeling to determine the conditions needed to initiate and sustain hydrofracture on Helheim Glacier, Greenland. We find that local stress conditions alone can drive crevasse tips into the firn aquifer, allowing hydrofracture initiation year-round. We infer inland expansion of crevasses over the firn aquifer from crevasse-nucleated whaleback dune formation and Global Navigation Satellite System-station detected crevasse opening extending 14 and 4 km, respectively, inland from the current, farthest-upstream drainage point. Using our LEFM model, we identify three vulnerable regions with coincidence between dry crevasse depth and water table variability, indicating potential future inland firn aquifer drainage sites. These results suggest the downstream boundary of firn aquifers can migrate inland under future warming scenarios and may already be underway.https://www.cambridge.org/core/product/identifier/S0022143024000789/type/journal_articlecrevassesglacier modelingpolar firnremote sensingwind-blown snow |
| spellingShingle | Jessica Z. Mejia Kristin Poinar Colin R. Meyer Aleah N. Sommers Winnie Chu Mechanisms for upstream migration of firn aquifer drainage: preliminary observations from Helheim Glacier, Greenland Journal of Glaciology crevasses glacier modeling polar firn remote sensing wind-blown snow |
| title | Mechanisms for upstream migration of firn aquifer drainage: preliminary observations from Helheim Glacier, Greenland |
| title_full | Mechanisms for upstream migration of firn aquifer drainage: preliminary observations from Helheim Glacier, Greenland |
| title_fullStr | Mechanisms for upstream migration of firn aquifer drainage: preliminary observations from Helheim Glacier, Greenland |
| title_full_unstemmed | Mechanisms for upstream migration of firn aquifer drainage: preliminary observations from Helheim Glacier, Greenland |
| title_short | Mechanisms for upstream migration of firn aquifer drainage: preliminary observations from Helheim Glacier, Greenland |
| title_sort | mechanisms for upstream migration of firn aquifer drainage preliminary observations from helheim glacier greenland |
| topic | crevasses glacier modeling polar firn remote sensing wind-blown snow |
| url | https://www.cambridge.org/core/product/identifier/S0022143024000789/type/journal_article |
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