Dataset Open Access

Lateral moraine elevation differences along a debris covered moraine

van Woerkom, Teun; Kraaijenbrink, Philip

Researcher(s)
Steiner, J. F.; Miles, Evan; Immerzeel, W.W.

Debris-covered glaciers in the Himalaya play an important role in the high-altitude water cycle.
The thickness of the debris layer is a key control of the melt rate of those glaciers, yet little is known about
the relative importance of the three potential sources of debris supply: the rockwalls, the glacier bed and the
lateral moraines. In this study, we hypothesize that mass movement from the lateral moraines is a significant
debris supply to debris-covered glaciers, in particular when the glacier is disconnected from the rockwall due to
downwasting. To test this hypothesis, eight high-resolution and highly accurate digital elevation models from the
lateral moraines of the debris-covered Lirung Glacier in Nepal are used. These are created using structure from
motion (SfM), based on images captured using an unmanned aerial vehicle between May 2013 and April 2018.
The analysis shows that mass transport results in an elevation change on the lateral moraines with an average rate
of -0.31 +/- 0.26 m/year during this period, partly related to sub-moraine ice melt. There is a higher elevation
change rate observed in the monsoon (-0.39 +/- 0.74 m/year) than in the dry season (-0.23 +/- 0.68 m/year).
The lower debris aprons of the lateral moraines decrease in elevation at a faster rate during both seasons, probably
due to the melt of ice below. The surface lowering rates of the upper gullied moraine, with no ice core below,
translate into an annual increase in debris thickness of 0.08 m/year along a narrow margin of the glacier surface,
with an observed absolute thickness of approximately 1 m, reducing melt rates of underlying glacier ice. Further
research should focus on how large this negative feedback is in controlling melt and how debris is redistributed
on the glacier surface. This dataset contains the elevation differences on the moraine as presented in the van Woerkom et al. (2019).

Further funding was provided by the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (grant no. 016.161.308).
Files (2.5 GB)
Name Size
fin_20131022_20130518.tif
md5:4fd4628ff1f92283eee8e3cb12279edb
364.2 MB Download
fin_20160430_20151018.tif
md5:54e4e9c873361c87a124e30f961d6442
364.2 MB Download
fin_20161006_20160430.tif
md5:33a4fb6079e25cb01c9a709be0484fc5
364.1 MB Download
fin_20170420_20161006.tif
md5:33797274a83160a8cfd92e1cbb3dde4b
364.2 MB Download
fin_20171019_20170420.tif
md5:b47b4bb468542ca0470247a0943261e8
364.1 MB Download
fin_20180428_20130518.tif
md5:68eb82feb8d59ddd083c4bc62fc7f8a2
364.2 MB Download
fin_20180428_20171019.tif
md5:2541bc5452a85dd35493c25bb70085f0
364.1 MB Download
ReadMe_MetaData.txt
md5:1425b2819386fb012ba794049eca70dc
365 Bytes Download
10
1
views
downloads
All versions This version
Views 1010
Downloads 11
Data volume 365 Bytes365 Bytes
Unique views 99
Unique downloads 11

Share

Cite as