Constraining regional glacier reconstructions using past ice thickness of deglaciating areas – a case study in the European Alps
<p>In order to assess future glacier evolution and meltwater runoff, accurate knowledge on the volume and the ice thickness distribution of glaciers is crucial. However, in situ observations of glacier thickness are sparse in many regions worldwide due to the difficulty of undertaking field su...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-06-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/17/2285/2023/tc-17-2285-2023.pdf |
| _version_ | 1797808979586318336 |
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| author | C. Sommer J. J. Fürst M. Huss M. Huss M. Huss M. H. Braun |
| author_facet | C. Sommer J. J. Fürst M. Huss M. Huss M. Huss M. H. Braun |
| author_sort | C. Sommer |
| collection | DOAJ |
| description | <p>In order to assess future glacier evolution and
meltwater runoff, accurate knowledge on the volume and the ice thickness
distribution of glaciers is crucial. However, in situ observations of
glacier thickness are sparse in many regions worldwide due to the difficulty
of undertaking field surveys. This lack of in situ measurements can be
partially overcome by remote-sensing information. Multi-temporal and
contemporaneous data on glacier extent and surface elevation provide past
information on ice thickness for retreating glaciers in the newly
deglacierized regions. However, these observations are concentrated near the
glacier snouts, which is disadvantageous because it is known to introduce
biases in ice thickness reconstruction approaches. Here, we show a strategy
to overcome this generic limitation of so-called retreat thickness
observations by applying an empirical relationship between the ice viscosity
at locations with in situ observations and observations from digital elevation model (DEM) differencing at the glacier margins. Various datasets from the European
Alps are combined to model the ice thickness distribution of Alpine glaciers
for two time steps (1970 and 2003) based on the observed thickness in regions
uncovered from ice during the study period. Our results show that the
average ice thickness would be substantially underestimated (<span class="inline-formula">∼</span> 40 %) when relying solely on thickness observations from previously
glacierized areas. Thus, a transferable topography-based viscosity scaling
is developed to correct the modelled ice thickness distribution. It is shown
that the presented approach is able to reproduce region-wide glacier
volumes, although larger uncertainties remain at a local scale, and thus might
represent a powerful tool for application in regions with sparse
observations.</p> |
| first_indexed | 2024-03-13T06:45:31Z |
| format | Article |
| id | doaj.art-ca53a49f126b492fbeb2eb4ff5621525 |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-03-13T06:45:31Z |
| publishDate | 2023-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-ca53a49f126b492fbeb2eb4ff56215252023-06-08T07:34:15ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242023-06-01172285230310.5194/tc-17-2285-2023Constraining regional glacier reconstructions using past ice thickness of deglaciating areas – a case study in the European AlpsC. Sommer0J. J. Fürst1M. Huss2M. Huss3M. Huss4M. H. Braun5Institut für Geographie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, GermanyInstitut für Geographie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, GermanySwiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, SwitzerlandLaboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zürich, Zurich, SwitzerlandDepartment of Geosciences, University of Fribourg, Fribourg, SwitzerlandInstitut für Geographie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany<p>In order to assess future glacier evolution and meltwater runoff, accurate knowledge on the volume and the ice thickness distribution of glaciers is crucial. However, in situ observations of glacier thickness are sparse in many regions worldwide due to the difficulty of undertaking field surveys. This lack of in situ measurements can be partially overcome by remote-sensing information. Multi-temporal and contemporaneous data on glacier extent and surface elevation provide past information on ice thickness for retreating glaciers in the newly deglacierized regions. However, these observations are concentrated near the glacier snouts, which is disadvantageous because it is known to introduce biases in ice thickness reconstruction approaches. Here, we show a strategy to overcome this generic limitation of so-called retreat thickness observations by applying an empirical relationship between the ice viscosity at locations with in situ observations and observations from digital elevation model (DEM) differencing at the glacier margins. Various datasets from the European Alps are combined to model the ice thickness distribution of Alpine glaciers for two time steps (1970 and 2003) based on the observed thickness in regions uncovered from ice during the study period. Our results show that the average ice thickness would be substantially underestimated (<span class="inline-formula">∼</span> 40 %) when relying solely on thickness observations from previously glacierized areas. Thus, a transferable topography-based viscosity scaling is developed to correct the modelled ice thickness distribution. It is shown that the presented approach is able to reproduce region-wide glacier volumes, although larger uncertainties remain at a local scale, and thus might represent a powerful tool for application in regions with sparse observations.</p>https://tc.copernicus.org/articles/17/2285/2023/tc-17-2285-2023.pdf |
| spellingShingle | C. Sommer J. J. Fürst M. Huss M. Huss M. Huss M. H. Braun Constraining regional glacier reconstructions using past ice thickness of deglaciating areas – a case study in the European Alps The Cryosphere |
| title | Constraining regional glacier reconstructions using past ice thickness of deglaciating areas – a case study in the European Alps |
| title_full | Constraining regional glacier reconstructions using past ice thickness of deglaciating areas – a case study in the European Alps |
| title_fullStr | Constraining regional glacier reconstructions using past ice thickness of deglaciating areas – a case study in the European Alps |
| title_full_unstemmed | Constraining regional glacier reconstructions using past ice thickness of deglaciating areas – a case study in the European Alps |
| title_short | Constraining regional glacier reconstructions using past ice thickness of deglaciating areas – a case study in the European Alps |
| title_sort | constraining regional glacier reconstructions using past ice thickness of deglaciating areas a case study in the european alps |
| url | https://tc.copernicus.org/articles/17/2285/2023/tc-17-2285-2023.pdf |
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