Mine

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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New Estimate of Ice Sheet Runoff at Isua Site

Posted by William Colgan on April 14, 2015
Applied Glaciology, New Research / No Comments

My colleague Lukas Arenson and I have a paper in the Proceedings of Mine Water Solutions in Extreme Environments this month, which uses the Isua site in Southwest Greenland as a case study for extreme runoff in proglacial environments (Arenson and Colgan, 2015). The recently approved Isua mine will be an open pit mine intersecting the ice sheet, with ice pit walls around about half the pit, to access what is presently a subglacial iron deposit (site overview here). Using a Monte Carlo approach, we estimate a 95 % (or two sigma) upper confidence limit of 2.8·109 L/day of ice sheet runoff potentially reaching the Isua site in July and August. While this potential inflow rate, equivalent to 44 t/s, is relatively large in the context of conventional mine water management, it is relatively small in the context of contemporary Greenland ice loss due to climate change, which is approximately 8,300 t/s when averaged over a year (Andersen et al., 2015).

Isua_meltwater_runoff_estimate

Minimum and maximum plausible supraglacial ice sheet catchments associated with the Isua site. Shading denotes mean annual meltwater runoff over the 2004 to 2013. Background image source is Landsat 8 (source: Arenson and Colgan, 2015).

To place our estimate in context, London Mining Plc, the initial developer of the Isua site, presented a pre-feasibility study water balance in which ice sheet runoff into the pit was estimated as 7.8·106 m3/year (London Mining, 2011). Assuming a 60-day melt season, this is equivalent to an average site inflow of 1.3·108 L/day. Our estimate is therefore 22 times greater than the design estimate. There are many potential sources of uncertainty when assessing ice sheet runoff, including model uncertainty and climatic variability, but by far the biggest source of uncertainty is delineating the ice sheet catchment draining to a specific portion of the ice sheet margin. Regardless of whether 108 or 109 L/day of meltwater is flowing into the Isua site, it will certainly be a challenging operating environment, and will require some very adaptive engineering to minimize site contact water!

Isua_SNC_Budget

Proponent water budget for the Isua Mine (source: London Mining, 2011).

Isua_2011 173

Oblique aerial photograph looking west from the Greenland ice sheet across the Isua site in 2011. Deeply incised supraglacial meltwater channels are visible draining towards the margin. (source: Lukas Arenson)

References

Andersen et al., 2015. Basin-scale partitioning of Greenland ice sheet mass balance components (2007–2011). Earth and Planetary Science Letters 409: 89-95.

Arenson and Colgan. 2015. Water management challenges associated with mining projects in Greenland. Proceedings of Mine Water Solutions in Extreme Environments. 533-543.

London Mining PLC. 2011. Isua iron ore project: Isua 15 Mtpa scoping study report.

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Glacier Mining Photos & Videos (Open File)

Posted by William Colgan on February 03, 2015
Applied Glaciology, Glaciers and Society / No Comments

I have started this open file of selected glacier mining photos and videos with content mostly gleaned from Twitter. At present its coverage is limited to Kumtor Mine, Kyrgyzstan, but I am interested in content that illustrates the unique geotechnical challenges of working with glaciers from other proglacial mining projects too. So please contact me if you have some!

Photos

Open ice pit at Kumtor Mine, Kyrgyzstan in 2013 (via Ryskeldi Satke).

Open ice pit at Kumtor Mine, Kyrgyzstan in 2013 (via Ryskeldi Satke).

6 - активисты Саруу, июль 2013 посещ Кумтор

An excavator used for glacier mining at Kumtor Mine, Kyrgyzstan (via Ryskeldi Satke).

4 - активисты Саруу, июль 2013 посещ. Кумтор

A glacier cut face at Kumtor Mine, Kyrgyzstan (via Ryskeldi Satke).

 

Videos

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Proglacial Mining Projects (Open File)

Posted by William Colgan on January 08, 2015
Applied Glaciology, Glaciers and Society / No Comments

Proglacial mines, meaning mining operations adjacent to, or very close to, glaciers, face a variety of unique glaciological challenges not present in conventional mining operations: (1) Removing ice overburden to access a subglacial ore introduces both ice excavation and ice flow management challenges. (2) In addition to potential crevasse hazards, supraglacial vehicle access roads must use adaptive engineering to counteract ice movement (both horizontal and vertical) as well as differential surface ablation. (3) Tremendous glacier meltwater runoff, concentrated during the summer melt season, can be difficult to route across highly transient glacier surfaces in order to minimize site inflow/contact water. (4) The dust created by open pit operations or access roads can darken the surface of nearby glaciers, enhancing their solar absorption and surface melt rates, and ultimately expand the impact footprint of a mine. (5) The catastrophic drainage of supraglacial and/or ice-dammed lakes represent outburst flood hazards which can rapidly increase site inflow rates. (6) Subglacial hydrology can interact with the groundwater seepage in underground mining operations beneath glaciers. We touch on some of these glaciological hazards in the new textbook: “Snow and Ice-Related Hazards, Risks, and Disasters”. These geotechnical challenges make proglacial mining projects very unique. I started this “open file” inventory of proglacial mining projects (past, present and future) and their associated glaciological challenges as I pull together information for an applied glaciology review paper. Please alert me to any errors or oversights!

ProjectPrime
Minerals
LocationGlaciological ChallengesApparent
Status
Isua
[Fig. 1]
Fe 65.195 °N, 49.790 °W
(Greenland)
- ice removal / flow management
- glacier access roads
- meltwater runoff
- supraglacial lake outbursts
- darkening of nearby glaciers
Approved in 2013.
Kumtor
[Fig. 2]
Au41.862 °N, 78.196 °E
(Kyrgyzstan)
- ice removal / flow management
- glacier access roads
- meltwater runoff
- darkening of nearby glaciers
Active since 1997.
Kerr-Sulphurets-
Mitchell
[Fig. 3]
Au, Ag, Cu, Mo56.491 °N, 130.335 °W
(Canada)
- glacier access roads
- meltwater runoff
- darkening of nearby glaciers
Approved in 2014.
TutoN/A76.417 °N, 68.269°W
(Greenland)
- ice removal / flow management
- glacier access roads
- meltwater runoff
Historic project (1955 to 1959).
GranducCu56.247 °N, 130.089 °W
(Canada)
- ice removal / flow management
- meltwater runoff
- darkening of nearby glaciers
Historic project (1964 to 1983).
MalmbjergMo 71.964 °N, 24.289 °W
(Greenland)
- glacier access roads
- meltwater runoff
- darkening of nearby glaciers
Prospect.
Brucejack
[Fig. 3]
Au, Ag56.468 °N, 130.164 °W
(Canada)
- glacier access roads
- meltwater runoff
Approved in 2015.
Maarmorilik
(Phase Two expansion)
Zn, Pb71.094 °N, 51.027°W
(Greenland)
- meltwater runoff
- darkening of nearby glaciers
Prospect.
Svea Nord | Gruve
[Fig. 6]
C77.893 °N, 16.689 °E
(Norway)
- subglacial miningActive since 2001.
El Morro
(La Fortuna expansion)
[Fig. 4]
Cu, Au33.167 °S, 70.274 °W
(Chile)
- darkening of nearby glaciersActive since c. 2008.
Permit suspended in 2014.
Pascua Lama
[Fig. 5]
Au, Ag29.327 °S, 70.035°W
(Chile / Argentina)
- darkening of nearby glaciersActive since 2010.
Permit suspended in 2013.
KvanefjeldU60.963 °N, 45.957 °W
(Greenland)
- darkening of nearby glaciersProspect.
Red MountainAu, Ag55.970 °N, 129.721 °W
(Canada)
- proglacial and/or subglacial depositsProspect.
Grasberg [Fig. 7]Au, Cu4.060 °S, 137.146 °E
(Indonesia)
- darkening of nearby glaciers
- glacier removal to access subglacial deposit
Active since c. 1995.

Below are some site overview figures, they are available for distribution without attribution tags as well. I hope to make one for each project by the end of 2015. Content on this page can be cited as:

Colgan, W., H. Thomsen and M. Citterio. in press. Unique Applied Glaciology Challenges of Proglacial Mining. Geological Survey of Denmark and Greenland Bulletin.

Isua_Mine

Figure 1 – The Isua Mine in Greenland: Contemporary ice margins, proposed approximate pit area, and winter 2005/06 ice surface velocity vectors overlaid on a 2014 Landsat image.

Kumtor_Mine

Figure 2 – The Kumtor mine in Kyrgyzstan: Historic ice margins and contemporary mine area overlaid on a 2014 Landsat image.

Kerr-Sulphurets-Mitchell_Mine_Brucejack_Prospect

Figure 3 – The Kerr-Sulphurets-Mitchell Mine and Bruckjack Prospect in Canada: Contemporary ice margins, approximate mine surface areas, and proposed supraglacial access roads overlaid on a 2014 Landsat image.

El_Morro_Mine

Figure 4 – The El Morro mine in Chile: Contemporary ice margins and mine area overlaid on a 2014 Landsat image.

Pascua_Lama_Mine

Figure 5 – The Pascua Lama mine on the Chile/Argentina border: Contemporary ice margins and mine area overlaid on a 2014 Landsat image. The Valadero mine is also visible immediately south of the Pascua Lama mine.

Svea_Nord_and_Gruve_Mines

Figure 6 – The Svea Nord / Gruve Mines in Svalbard (Norway): Contemporary ice margins and underground mine area overlaid on a 2014 Landsat image.

Grasberg_w_label2

Figure 7 – Grasberg Mine in Indonesia: Contemporary mine area and ice margins in a 2003 Landsat image.

 

 

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