Jamieson and colleagues published a very neat investigation of the applied glaciology challenges at Kumtor Mine, Kyrgyzstan, this week in the AGU Journal of Geophysical Research: Earth Surface (open access here). The recovery of subglacial gold deposits at Kumtor Mine has necessitated the excavation of an open ice pit into the Lysii and Davidov Glaciers. In addition to excavating glacier overburden, a major geotechnical challenge at Kumtor Mine has been managing the flow of both glaciers. In their study, Jamieson et al. (2015) use a comprehensive set of high resolution satellite images to document recent artificial surges induced in both these glaciers in response to mining activities. Photos released by Radio Free Europe in 2013 suggest that these artificial surges quite adversely impacted mining operations (Figure 1).
Figure 1 – Infrastructure damage resulting from what is now a confirmed glacier advance at the Kumtor Mine in Kyrgyzstan (originally discussed in this earlier post)
The dumping of waste rock on both glaciers, in which waste rock piles reached up to 180 m thick, substantially increased the driving stress of the ice beneath. Given that ice deformation is related to driving stress to an exponent of three, and potentially higher exponents at higher driving stresses, this resulted in a significant increase in ice velocity. Jamieson et al. (2015) estimate that surface velocities of the Davidov Glacier increased from a few meters per year to several hundred meters per year within a decade. During this time, the Lysii and Davidov Glaciers advanced by 1.2 and 3.2 km, respectively, with Davidov Glacier terminus advance reaching 350 meters per year in c. 2012 (Figure “7”).
This study is probably the most textbook-comprehensive documentation of a human-induced artificial glacier surge to date, and will provide a great resource for my students to debate the sometimes fine line between geotechnical misstep and natural hazard!
Reference
Quick blog on new study of human-induced 3.2 km #glacier surge at #Kumtor mine: http://t.co/mTYVeQDzcb pic.twitter.com/ONMkQETlRm
— William Colgan (@GlacierBytes) July 27, 2015
