Aspect controls the survival of ice cliffs on debris-covered glaciers.
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| Title: | Aspect controls the survival of ice cliffs on debris-covered glaciers. |
|---|---|
| Authors: | Buri, Pascal1 buri@ifu.baug.ethz.ch, Pellicciotti, Francesca2 |
| Source: | Proceedings of the National Academy of Sciences of the United States of America. 4/24/2018, Vol. 115 Issue 17, p4369-4374. 6p. |
| Subjects: | Debris avalanches, Glaciers, Cliffs, Mass budget (Geophysics) |
| Geographic Terms: | Langtang National Park (Nepal) |
| Abstract: | Supraglacial ice cliffs exist on debris-covered glaciers worldwide, but despite their importance as melt hot spots, their life cycle is little understood. Early field observations had advanced a hypothesis of survival of north-facing and disappearance of south-facing cliffs, which is central for predicting the contribution of cliffs to total glacier mass losses. Their role as windows of energy transfer suggests they may explain the anomalously high mass losses of debris-covered glaciers in High Mountain Asia (HMA) despite the insulating debris, currently at the center of a debated controversy. We use a 3D model of cliff evolution coupled to very high-resolution topographic data to demonstrate that ice cliffs facing south (in the Northern Hemisphere) disappear within a few months due to enhanced solar radiation receipts and that aspect is the key control on cliffs evolution. We reproduce continuous flattening of south-facing cliffs, a result of their vertical gradient of incoming solar radiation and sky view factor. Our results establish that only north-facing cliffs are recurrent features and thus stable contributors to the melting of debris-covered glaciers. Satellite observations and mass balance modeling confirms that few south-facing cliffs of small size exist on the glaciers of Langtang, and their contribution to the glacier volume losses is very small (~1%). This has major implications for the mass balance of HMA debris-covered glaciers as it provides the basis for new parameterizations of cliff evolution and distribution to constrain volume losses in a region where glaciers are highly relevant as water sources for millions of people. [ABSTRACT FROM AUTHOR] |
| Copyright of Proceedings of the National Academy of Sciences of the United States of America is the property of National Academy of Sciences and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 129331143 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Aspect controls the survival of ice cliffs on debris-covered glaciers. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Buri%2C+Pascal%22">Buri, Pascal</searchLink><relatesTo>1</relatesTo><i> buri@ifu.baug.ethz.ch</i><br /><searchLink fieldCode="AR" term="%22Pellicciotti%2C+Francesca%22">Pellicciotti, Francesca</searchLink><relatesTo>2</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Proceedings+of+the+National+Academy+of+Sciences+of+the+United+States+of+America%22">Proceedings of the National Academy of Sciences of the United States of America</searchLink>. 4/24/2018, Vol. 115 Issue 17, p4369-4374. 6p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Debris+avalanches%22">Debris avalanches</searchLink><br /><searchLink fieldCode="DE" term="%22Glaciers%22">Glaciers</searchLink><br /><searchLink fieldCode="DE" term="%22Cliffs%22">Cliffs</searchLink><br /><searchLink fieldCode="DE" term="%22Mass+budget+%28Geophysics%29%22">Mass budget (Geophysics)</searchLink> – Name: SubjectGeographic Label: Geographic Terms Group: Su Data: <searchLink fieldCode="DE" term="%22Langtang+National+Park+%28Nepal%29%22">Langtang National Park (Nepal)</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Supraglacial ice cliffs exist on debris-covered glaciers worldwide, but despite their importance as melt hot spots, their life cycle is little understood. Early field observations had advanced a hypothesis of survival of north-facing and disappearance of south-facing cliffs, which is central for predicting the contribution of cliffs to total glacier mass losses. Their role as windows of energy transfer suggests they may explain the anomalously high mass losses of debris-covered glaciers in High Mountain Asia (HMA) despite the insulating debris, currently at the center of a debated controversy. We use a 3D model of cliff evolution coupled to very high-resolution topographic data to demonstrate that ice cliffs facing south (in the Northern Hemisphere) disappear within a few months due to enhanced solar radiation receipts and that aspect is the key control on cliffs evolution. We reproduce continuous flattening of south-facing cliffs, a result of their vertical gradient of incoming solar radiation and sky view factor. Our results establish that only north-facing cliffs are recurrent features and thus stable contributors to the melting of debris-covered glaciers. Satellite observations and mass balance modeling confirms that few south-facing cliffs of small size exist on the glaciers of Langtang, and their contribution to the glacier volume losses is very small (~1%). This has major implications for the mass balance of HMA debris-covered glaciers as it provides the basis for new parameterizations of cliff evolution and distribution to constrain volume losses in a region where glaciers are highly relevant as water sources for millions of people. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Proceedings of the National Academy of Sciences of the United States of America is the property of National Academy of Sciences and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1073/pnas.1713892115 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 6 StartPage: 4369 Subjects: – SubjectFull: Debris avalanches Type: general – SubjectFull: Glaciers Type: general – SubjectFull: Cliffs Type: general – SubjectFull: Mass budget (Geophysics) Type: general – SubjectFull: Langtang National Park (Nepal) Type: general Titles: – TitleFull: Aspect controls the survival of ice cliffs on debris-covered glaciers. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Buri, Pascal – PersonEntity: Name: NameFull: Pellicciotti, Francesca IsPartOfRelationships: – BibEntity: Dates: – D: 24 M: 04 Text: 4/24/2018 Type: published Y: 2018 Identifiers: – Type: issn-print Value: 00278424 Numbering: – Type: volume Value: 115 – Type: issue Value: 17 Titles: – TitleFull: Proceedings of the National Academy of Sciences of the United States of America Type: main |
| ResultId | 1 |
