Davidov

Artificial Glacier Surges at Kumtor Mine

Posted by William Colgan on July 27, 2015
Applied Glaciology, New Research / No Comments

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).

Kumtor_glacier_damage

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”).

Jamieson1

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

(Jamieson, S., M. Ewertowski and D. Evans. 2015. Rapid advance of two mountain glaciers in response to mine-related debris loading. Journal of Geophysical Research: Earth Surface. 120: doi:10.1002/2015JF003504.

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Proglacial Mines: Ice Flow and Infrastructure

Posted by William Colgan on September 15, 2014
Applied Glaciology, Glaciology History / No Comments

Last week Radio Free Europe released some photos of the Kumtor Gold Mine in Kyrgyzstan, where Centerra Gold Inc has been excavating approximately 10 MT of ice per year from the Lysii and Davidov Glaciers that flow into the open pit. In 2012 Mining.com reported that production estimates were down-revised due to a combination of “substantial acceleration of ice” and labor disruptions. These recent photos show infrastructure damage resulting from what appears to be glacier advance.

While no doubt curious, such a geotechnical management challenge would not be unique. In 1977, Eyles and Rogerson described how several positive mass balance years on the Berendon Glacier in Canada could cause sufficient terminus advance to threaten the adjacent Granduc Operating Company ore processing plant. In response, the Granduc Operating Company began discharging 30°C wastewater, year-round for five years, directly on to the glacier terminus to prevent advance. Glaciers are indeed dynamic landscape features for planning purposes!

Radio Free Europe photo series: http://www.rferl.org/content/qishloq-ovozi-kumtor-gold-mine-bad-shape/26555319.html

Eyles, N. and R. Rogerson. 1977. Artificially induced thermokarst in active glacier ice: An example from northwest British Columbia, Canada. Journal of Glaciology. 18: 437–444.

Kumtor_glacier_damage

Infrastructure damage resulting from what appears to be glacier advance at the Kumtor Mine in Kyrgyzstan (from Radio Free Europe: Kumtor Gold Mine Appears To Be In Bad Shape)

Granduc_glacier_thermokarst

Intentional thermokarst of the Berendon Glacier by the Granduc Operating Company. Red line denotes Summit Lake stream, which has been diverted upglacier at A. Hot waste water is added at B, and flow is subglacial until C. The stream exits the glacier terminus at D. (from Eyles and Rogerson, 1977)

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