Detection and characterization of discontinuous motion on Thompson Glacier, Canadian High Arctic, using synthetic aperture radar speckle tracking and ice-flow modeling
We investigate unusual discontinuous glacier motion on Thompson Glacier, Umingmat Nunaat, Arctic Canada, using synthetic aperture radar (SAR) images and ice-flow modeling. A novel intensity-rescaling scheme is developed to reduce errors in high-resolution speckle tracking, resulting in a ~25% improv...
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| Format: | Article |
| Jezik: | English |
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Cambridge University Press
2023-12-01
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| Serija: | Journal of Glaciology |
| Teme: | |
| Online dostop: | https://www.cambridge.org/core/product/identifier/S0022143023000679/type/journal_article |
| _version_ | 1826937793436188672 |
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| author | Giovanni Corti Bernhard Rabus Gwenn E. Flowers |
| author_facet | Giovanni Corti Bernhard Rabus Gwenn E. Flowers |
| author_sort | Giovanni Corti |
| collection | DOAJ |
| description | We investigate unusual discontinuous glacier motion on Thompson Glacier, Umingmat Nunaat, Arctic Canada, using synthetic aperture radar (SAR) images and ice-flow modeling. A novel intensity-rescaling scheme is developed to reduce errors in high-resolution speckle tracking, resulting in a ~25% improvement in accuracy. Interferometric SAR (InSAR) and speckle tracking using high resolution RADARSAT-2 data indicate velocity discontinuities of up to 1 cm d−1 across deep and longitudinally extensive supraglacial channels on Thompson Glacier. We use a cross-sectional finite-element ice-flow model to determine the conditions under which velocity discontinuities of the observed magnitude and signature are possible. The modeling suggests that discontinuous motion across (long and straight) supraglacial channels can occur without ice fracture and under a wide variety of glacier thermal structures, including in fully temperate glaciers. Despite the wide range of conditions conducive to discontinuous motion, the form we observe requires that the associated channels be deep, longitudinally extensive and located in regions of lateral shearing. We speculate that these combined conditions are rare except on polythermal glaciers, where drainage features such as moulins are comparatively scarce and lower deformation rates allow channels to incise consistently and persist over many years. |
| first_indexed | 2024-03-12T02:16:32Z |
| format | Article |
| id | doaj.art-c4c0da5de13c4bd6b8596bc4f4daff2c |
| institution | Directory Open Access Journal |
| issn | 0022-1430 1727-5652 |
| language | English |
| last_indexed | 2025-02-17T18:46:15Z |
| publishDate | 2023-12-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj.art-c4c0da5de13c4bd6b8596bc4f4daff2c2024-12-11T10:15:39ZengCambridge University PressJournal of Glaciology0022-14301727-56522023-12-01691860187310.1017/jog.2023.67Detection and characterization of discontinuous motion on Thompson Glacier, Canadian High Arctic, using synthetic aperture radar speckle tracking and ice-flow modelingGiovanni Corti0https://orcid.org/0000-0003-2381-9951Bernhard Rabus1Gwenn E. Flowers2https://orcid.org/0000-0002-3574-9324Department of Earth Sciences, Simon Fraser University, Burnaby, BC, CanadaDepartment of Engineering Sciences, Simon Fraser University, Burnaby, BC, CanadaDepartment of Earth Sciences, Simon Fraser University, Burnaby, BC, CanadaWe investigate unusual discontinuous glacier motion on Thompson Glacier, Umingmat Nunaat, Arctic Canada, using synthetic aperture radar (SAR) images and ice-flow modeling. A novel intensity-rescaling scheme is developed to reduce errors in high-resolution speckle tracking, resulting in a ~25% improvement in accuracy. Interferometric SAR (InSAR) and speckle tracking using high resolution RADARSAT-2 data indicate velocity discontinuities of up to 1 cm d−1 across deep and longitudinally extensive supraglacial channels on Thompson Glacier. We use a cross-sectional finite-element ice-flow model to determine the conditions under which velocity discontinuities of the observed magnitude and signature are possible. The modeling suggests that discontinuous motion across (long and straight) supraglacial channels can occur without ice fracture and under a wide variety of glacier thermal structures, including in fully temperate glaciers. Despite the wide range of conditions conducive to discontinuous motion, the form we observe requires that the associated channels be deep, longitudinally extensive and located in regions of lateral shearing. We speculate that these combined conditions are rare except on polythermal glaciers, where drainage features such as moulins are comparatively scarce and lower deformation rates allow channels to incise consistently and persist over many years.https://www.cambridge.org/core/product/identifier/S0022143023000679/type/journal_articleArctic glaciologyglacier flowglacier modelingice velocityremote sensing |
| spellingShingle | Giovanni Corti Bernhard Rabus Gwenn E. Flowers Detection and characterization of discontinuous motion on Thompson Glacier, Canadian High Arctic, using synthetic aperture radar speckle tracking and ice-flow modeling Journal of Glaciology Arctic glaciology glacier flow glacier modeling ice velocity remote sensing |
| title | Detection and characterization of discontinuous motion on Thompson Glacier, Canadian High Arctic, using synthetic aperture radar speckle tracking and ice-flow modeling |
| title_full | Detection and characterization of discontinuous motion on Thompson Glacier, Canadian High Arctic, using synthetic aperture radar speckle tracking and ice-flow modeling |
| title_fullStr | Detection and characterization of discontinuous motion on Thompson Glacier, Canadian High Arctic, using synthetic aperture radar speckle tracking and ice-flow modeling |
| title_full_unstemmed | Detection and characterization of discontinuous motion on Thompson Glacier, Canadian High Arctic, using synthetic aperture radar speckle tracking and ice-flow modeling |
| title_short | Detection and characterization of discontinuous motion on Thompson Glacier, Canadian High Arctic, using synthetic aperture radar speckle tracking and ice-flow modeling |
| title_sort | detection and characterization of discontinuous motion on thompson glacier canadian high arctic using synthetic aperture radar speckle tracking and ice flow modeling |
| topic | Arctic glaciology glacier flow glacier modeling ice velocity remote sensing |
| url | https://www.cambridge.org/core/product/identifier/S0022143023000679/type/journal_article |
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