Microstructures in a shear margin: Jarvis Glacier, Alaska
Microstructures, including crystallographic fabric, within the margin of streaming ice can exert strong control on flow dynamics. To characterize a natural setting, we retrieved three cores, two of which reached bed, from the flank of Jarvis Glacier, eastern Alaska Range, Alaska. The core sites lie...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Cambridge University Press
2021-12-01
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| Series: | Journal of Glaciology |
| Subjects: | |
| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143021000629/type/journal_article |
| _version_ | 1811155732645543936 |
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| author | Christopher Gerbi Stephanie Mills Renée Clavette Seth Campbell Steven Bernsen David Clemens-Sewall Ian Lee Robert Hawley Karl Kreutz Kate Hruby |
| author_facet | Christopher Gerbi Stephanie Mills Renée Clavette Seth Campbell Steven Bernsen David Clemens-Sewall Ian Lee Robert Hawley Karl Kreutz Kate Hruby |
| author_sort | Christopher Gerbi |
| collection | DOAJ |
| description | Microstructures, including crystallographic fabric, within the margin of streaming ice can exert strong control on flow dynamics. To characterize a natural setting, we retrieved three cores, two of which reached bed, from the flank of Jarvis Glacier, eastern Alaska Range, Alaska. The core sites lie ~1 km downstream of the source, with abundant water present in the extracted cores and at the base of the glacier. All cores exhibit dipping layers, a combination of debris bands and bubble-free domains. Grain sizes coarsen on average approaching the lateral margin. Crystallographic orientations are more clustered and with c-axes closer to horizontal nearer the lateral margin. The measured fabric is sufficiently weak to induce little mechanical anisotropy, but the data suggest that despite the challenging conditions of warm ice, abundant water and a short flow distance, many aspects of the microstructure, including measurable crystallographic fabric, evolved in systematic ways. |
| first_indexed | 2024-04-10T04:39:29Z |
| format | Article |
| id | doaj.art-56fd78f6e41e40bdacde81da7d90b88d |
| institution | Directory Open Access Journal |
| issn | 0022-1430 1727-5652 |
| language | English |
| last_indexed | 2024-04-10T04:39:29Z |
| publishDate | 2021-12-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj.art-56fd78f6e41e40bdacde81da7d90b88d2023-03-09T12:41:10ZengCambridge University PressJournal of Glaciology0022-14301727-56522021-12-01671163117610.1017/jog.2021.62Microstructures in a shear margin: Jarvis Glacier, AlaskaChristopher Gerbi0https://orcid.org/0000-0002-0619-4833Stephanie Mills1Renée Clavette2Seth Campbell3Steven Bernsen4David Clemens-Sewall5https://orcid.org/0000-0003-2496-5256Ian Lee6https://orcid.org/0000-0001-6871-266XRobert Hawley7https://orcid.org/0000-0001-8466-0839Karl Kreutz8Kate Hruby9School of Earth and Climate Sciences, University of Maine, Orono, ME, USASchool of Earth and Climate Sciences, University of Maine, Orono, ME, USASchool of Earth and Climate Sciences, University of Maine, Orono, ME, USASchool of Earth and Climate Sciences, University of Maine, Orono, ME, USA Climate Change Institute, University of Maine, Orono, ME, USASchool of Earth and Climate Sciences, University of Maine, Orono, ME, USAThayer School of Engineering, Dartmouth College, Hanover, NH, USADepartment of Geosciences and Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA, USADepartment of Earth Sciences, Dartmouth College, Hanover, NH, USASchool of Earth and Climate Sciences, University of Maine, Orono, ME, USASchool of Earth and Climate Sciences, University of Maine, Orono, ME, USAMicrostructures, including crystallographic fabric, within the margin of streaming ice can exert strong control on flow dynamics. To characterize a natural setting, we retrieved three cores, two of which reached bed, from the flank of Jarvis Glacier, eastern Alaska Range, Alaska. The core sites lie ~1 km downstream of the source, with abundant water present in the extracted cores and at the base of the glacier. All cores exhibit dipping layers, a combination of debris bands and bubble-free domains. Grain sizes coarsen on average approaching the lateral margin. Crystallographic orientations are more clustered and with c-axes closer to horizontal nearer the lateral margin. The measured fabric is sufficiently weak to induce little mechanical anisotropy, but the data suggest that despite the challenging conditions of warm ice, abundant water and a short flow distance, many aspects of the microstructure, including measurable crystallographic fabric, evolved in systematic ways.https://www.cambridge.org/core/product/identifier/S0022143021000629/type/journal_articleAnisotropic icearctic glaciologystructural glaciology |
| spellingShingle | Christopher Gerbi Stephanie Mills Renée Clavette Seth Campbell Steven Bernsen David Clemens-Sewall Ian Lee Robert Hawley Karl Kreutz Kate Hruby Microstructures in a shear margin: Jarvis Glacier, Alaska Journal of Glaciology Anisotropic ice arctic glaciology structural glaciology |
| title | Microstructures in a shear margin: Jarvis Glacier, Alaska |
| title_full | Microstructures in a shear margin: Jarvis Glacier, Alaska |
| title_fullStr | Microstructures in a shear margin: Jarvis Glacier, Alaska |
| title_full_unstemmed | Microstructures in a shear margin: Jarvis Glacier, Alaska |
| title_short | Microstructures in a shear margin: Jarvis Glacier, Alaska |
| title_sort | microstructures in a shear margin jarvis glacier alaska |
| topic | Anisotropic ice arctic glaciology structural glaciology |
| url | https://www.cambridge.org/core/product/identifier/S0022143021000629/type/journal_article |
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