The Kerr-Sulphurets-Mitchell (KSM) gold mine in British Columbia received provincial approval last week. The federal permitting decision is expected in November. The suite of three open pits are in close proximity to glaciers, with the ultimate outline of the Mitchell pit intersecting the present extent of Mitchell Glacier. The proponent report filed by Seabridge Gold Inc states: “The current recession rate of the Mitchell Glacier has been estimated by Seabridge geologists at 100 m per year. As mining progresses, melting of the ice is expected to clear the area for the ultimate pit and create space needed for a series of diversion dams and ponds as well as the required debris catch basins upstream of the diversion inlets.” Seabridge is also seeking to excavate a 22 km long haulage tunnel that will convey 120,000 tonnes per day of ore underneath glaciers north of the open pits. A 38 km long glacier road, which ascends Berendon Glacier, crosses a local topographic divide, and descends an unnamed glacier, will provide winter access to the trio of open pits. The Berendon Glacier access road would be close proximity to the Knipple Glacier access road proposed by Pretium Resources Inc to access the nearby Bruce Jack Mine. Presumably the KSM project will be keeping a close eye regional glacier projections!
Controversial Canadian KSM mine gets key govt. permits
KSM (Kerr-Sulphurets-Mitchell) Project: Canadian Environmental Assessment Agency
Kerr-Sulphurets-Mitchell Project glacier access road during the winter. The road ascends Berendon Glacier in the east, crosses the local topographic divide, and descends an unnamed glacier in the west.
Site map of the Mitchell Pit at the Kerr-Sulphurets-Michell gold mine. Purple line denotes haulage tunnel. Dashed black line denotes ultimate extent of Mitchell Pit. White areas denote glacier extent.
Posted by William Colgan
on September 15, 2014
, Glaciology History
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.
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)
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)