Remote-sensing-based analysis of the 1996 surge of Northern Inylchek Glacier, central Tien Shan, Kyrgyzstan

Author(s)
Hermann Häusler, Felix Ng, Alexander Kopecny, Diethard Leber
Abstract

The evolution of Northern Inylchek Glacier and its proglacial lake - Upper Lake Merzbacher - during its 1996 surge and the surrounding decades is analyzed with remote sensing imagery. Overall retreat of the glacier from1943 to 1996 enlarged the lake to 4 km long and≈100m deep. The surge in 1996 initiated between 12 September and 7 October and advanced the glacier by 3.7 km to override most of Upper Lake Merzbacher. The surge phase probably ended in December 1996 and involved mean flow velocities across the lower trunk of the glacier that reached 50md−1 over a 32-day period. Water displaced by the surge fromUpper LakeMerzbacher, totalling 1.5 × 108m3 in volume, accelerated filling of Lower Lake Merzbacher downvalley and helped trigger this marginal ice-dammed lake to outburst in a jökulhlaup around late November/early December. The characteristics and duration of the surge render it as similar to temperate glacier surges elsewhere. It may have been facilitated by low basal friction caused by water-saturated sediments in the upper lake bed. Furthermore, bathymetric measurements show that the surge evacuated much sediment into the upper lake, causing its depth to reduce from 20 to 30 min 1996 to 8m by 2005 and 2m by 2011; the corresponding deposition rates imply glacier-catchment specific mean sediment yields of 1.4 to 3.4 × 103 Mg km−2 a−1 in the years after the surge. Our study documents novel interactionswithin a cascade system of glaciers and lakes that exhibits surging and outburst-flood behavior.

Organisation(s)
External organisation(s)
University of Sheffield
Journal
Geomorphology
Volume
273
Pages
292-307
No. of pages
16
ISSN
0169-555X
DOI
https://doi.org/10.1016/j.geomorph.2016.08.021
Publication date
11-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
105906 Environmental geosciences, 105404 Geomorphology, 207402 Remote sensing, 105901 Glaciology
Keywords
ASJC Scopus subject areas
General Environmental Science, Earth-Surface Processes
Portal url
https://ucrisportal.univie.ac.at/en/publications/cc40005d-e41a-40c7-87b5-690d8b64745b