Automated detection of ice cliffs within supraglacial debris cover
Ice cliffs within a supraglacial debris cover have been identified as a source for high ablation relative to the surrounding debris-covered area. Due to their small relative size and steep orientation, ice cliffs are difficult to detect using nadir-looking space borne sensors. The method presente...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-05-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/12/1811/2018/tc-12-1811-2018.pdf |
| Summary: | Ice cliffs within a supraglacial debris cover have been identified as a
source for high ablation relative to the surrounding debris-covered area. Due
to their small relative size and steep orientation, ice cliffs are difficult
to detect using nadir-looking space borne sensors. The method presented here
uses surface slopes calculated from digital elevation model (DEM) data to map
ice cliff geometry and produce an ice cliff probability map. Surface slope
thresholds, which can be sensitive to geographic location and/or data
quality, are selected automatically. The method also attempts to include area
at the (often narrowing) ends of ice cliffs which could otherwise be
neglected due to signal saturation in surface slope data. The method was
calibrated in the eastern Alaska Range, Alaska, USA, against a control ice
cliff dataset derived from high-resolution visible and thermal data. Using
the same input parameter set that performed best in Alaska, the method was
tested against ice cliffs manually mapped in the Khumbu Himal, Nepal. Our
results suggest the method can accommodate different glaciological settings
and different DEM data sources without a data intensive (high-resolution,
multi-data source) recalibration. |
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| ISSN: | 1994-0416 1994-0424 |