In:
The Cryosphere, Copernicus GmbH, Vol. 12, No. 1 ( 2018-01-11), p. 95-101
Abstract:
Abstract. Glacier surges occur regularly in the
Karakoram, but the driving mechanisms, their frequency and its relation to a
changing climate remain unclear. In this study, we use digital elevation
models and Landsat imagery in combination with high-resolution imagery from
the Planet satellite constellation to quantify surface elevation changes and
flow velocities during a glacier surge of the Khurdopin Glacier in 2017.
Results reveal that an accumulation of ice volume above a clearly defined
steep section of the glacier tongue since the last surge in 1999 eventually
led to a rapid surge in May 2017 peaking with velocities above
5000 m a−1, which were among the fastest rates globally for a mountain
glacier. Our data reveal that velocities on the lower tongue increase
steadily during a 4-year build-up phase prior to the actual surge only to
then rapidly peak and decrease again within a few months, which confirms
earlier observations with a higher frequency of available velocity data. The
surge return period between the reported surges remains relatively constant
at ca. 20 years. We show the potential of a combination of repeat Planet and
ASTER imagery to (a) capture peak surge velocities that are easily missed by
less frequent Landsat imagery, (b) observe surface changes that indicate
potential drivers of a surge and (c) monitor hazards associated with a surge.
At Khurdopin specifically, we observe that the surging glacier blocks the
river in the valley and causes a lake to form, which may grow in subsequent
years and could pose threats to downstream settlements and infrastructure in
the case of a sudden breach.
Type of Medium:
Online Resource
ISSN:
1994-0424
DOI:
10.5194/tc-12-95-2018
DOI:
10.5194/tc-12-95-2018-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2393169-3
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