Quebrada Carhuascancha Glacier is in the Cordillera Blanca of Peru, draining the northeastern slopes of Huantsan. A glacier lake outburst flood was reported in the valley in 1965 from a landslide into one of the lakes. The region has experienced ongoing glacier loss with Racoviteanu et al (2008) noting a 22% loss in area from 1970-2003 in the Cordillera Blanca. They further observed an average rise of terminus elevation by 113m and an average rise in the median glacier elevation of glaciers of 66 m, with the greatest changes on the eastern side of the Cordillera. Vuille et al (2008) observed that the glacier in the Cordillera Blanca are not in balance with regional climate, and that tropical glaciers shrink in response to increased air temperature, which was the observed case in the Cordillera Blanca region. On three glaciers on nearby Nevado Queshque Marks and Seltzer (2005) observed volume loss and retreat due to warming. Examining temperature records from 29 stations in the Cordillera Blanca they found an average rising temperature trend ofof 0.26 1C per decade over the 1962-1999 period.
In this post the pink arrow notes the western margin of the lake that Carhuascancha reached in 1999 and 2000. The yellow arrow notes the terminus of the next glacier to the south of Carhuascancha, and the orange arrow a terminal-lateral moraine from the Little Ice Age. In 1999 and 2000 the glacier reaches just to the margin of the Laguna, and the southern glacier ends against a bedrock ridge. In both 2013 images Carhuascancha no longer reaches the lake terminating 250 m short of the lake and 200 m above the lake in elevation. The southern glacier terminates in a small lake that has formed. This small lake is also evident in the Google Earth imagery, which is an unknown date. Corihuasi Glacier and Chuecon Glacier in Cordillera Centrale, Yanashallasa Glacier and Artespnraju Glacier have all had a similar recent retreat.
1999 Landsat image
2000 Landsat image
2013 Landsat image
2013 Landsat image
Google Earth image
In the Cordillera Centrale of Peru a series of glaciers extends north from Pariacaca. Pariacaca is the pre-Incan god of water, appropriate name in this dry region, that is draped with glaciers and has numerous alpine lakes. In fact with glacier retreat the number of lakes is increasing. Here we examine the Chuecon Glacier which descends from Nevado Suerococha, and ends in a new lake before draining into the Rio Carhuapampa. This area has has escaped attention on its recent retreat. The retreat of the Chuecon Glacier over the last decade is documented with a comparison of Landsat and Google Earth imagery from 1997, 1998, 2005,2010 and 2012. The Chuecon Glacier terminus is indicated with a pink arrow in the Landsat images. The green arrow is the Manon Glacier. In 1997 and 1998 the lake at the terminus has not yet begun to form, by 2005 a small lake has developed at the north corner of the terminus. By 2010 the lake is 450 meters from north to south and 150 to 200 m east to west. The retreat from 1997 to 2010 is 200 meters. A closeup view of the glacier indicates that even in the accumulation zone bedrock is being exposed amidst the icefall and the accumulation zone margin in retreating, pink arrows in both images. The terminus currently is calving into the lake some, an upwelling area where the subglacial glacier runoff stream enters the lake is evident, yellow arrow. The terminus area also has ablation depressions forming an indication of stagnation, principally on the southern arm of the glacier, pink arrows. The purple arrow on the bottom image indicates the terminus in 1997. The combination of limited accumulation area and ablation depressions indicative of stagnation indicate a glacier that is not only retreating, but will not survive (Pelto, 2010). The ongoing field work at Quelcaya Ice Cap, led by Doug Hardy at UMASS, provides a detailed view of what is happening to glaciers in the region. Bryan Mark at Ohio State University has also been observing detailed changes around Mount Pucaranra, Peru.
In the Cordillera Centrale of Peru a series of glaciers extends north from Pariacaca. Pariacaca is the pre-Incan god of water, appropriate name in this dry region, that is draped with glaciers and has numerous alpine lakes. In fact with glacier retreat the number of lakes is increasing. Here we examine the Manon Glacier which descends from Nevado Suerococha and drains into the Rio Carhuapampa. This area has received little attention when it comes to glacier study. A glacier lake outburst flood from the Suerococha Basin in 1941 is the only noted event. The retreat of the Manon Glacier over the last decade is documented with a comparison of Landsat and Google Earth imagery from 1997, 1998, 2005,2010 and 2012. The retreat of these glaciers matches the more closely observed Cordillera Blanca and Quelcaya Ice Cap region (Mark., 2008 and Vuille et al, 2008). The Manon Glacier terminus is indicated with a green arrow in the Landsat images. The pink arrow is the Chuecon Glacier which will be the focus of a later post. In 1997 the lake at the terminus has not yet begun to form, by 2005 the lake has nearly reached its full size, and the glacier is still terminating in it. By 2010 and 2012 the glacier no longer reaches even the edge of the new lake. The retreat from 1997 to 2010 is 550 meters, the lake is 500 meters long. The 2010 Google Earth image indicates no snow snow on the southern half of the glacier, even at its highest altitude of 5200 m, the larger section coming off the main peak has a snowline at 5100 meters. A closeup of the terminus indicates that the southern portion of the glacier also has a number of features indicative of stagnation, pink arrows. Thesse are depressions that have higher debris concentration and are wind scoured, both enhancing melting. If the debris cover was a thick blanket it could retard melting. This type of ablation hollow is also seen at the top of the southern section of the glacier, indicating this part no longer has an accumulation zone and will melt away.
The Cordillera Blanca, Peru has the greatest concentration of glaciers of any region in the tropics. Glacier mass balance losses and glacier area losses in this range have been large since 1990 (Rivera,INRENA) Laguna Arhueycocha is proglacial lake dammed by a glacier end moraine emplaced by the Arhuey Glacier (AG) during the Little Ice Age. The glacier currently terminates in this lake. Moraine dammed lakes can be a hazard as they expand since the moraine material that comprises the dam is relatively unstable. The glacier still filled the lake basin in 1963 photographs. By 1991 the lake was 500 meters long (Reynolds Geoscience, 2003) . In a 1999 Landsat image the lake is 750 meters long, by 2002 IKONOS imagery the lake and 2003 Google Earth imagery indicates a lake that is 1050 meters long, and finally in 2011 Landsat imagery the lake is 1200 meters long. The 2003 Google Earth image has the terminus position in red for 1991, purple 2002 and green 2011 indicated. The red arrow points to the artificial outlet channel. The 700 meter retreat since 1999 leaves only a tiny bit of the glacier in contact with the lake, and it appears the lake will not extend much further.
To relieve the threat of an expanding glacier lake breaking its dam, a (Reynolds Geoscience, 2003) 122 meter long channelthat is 12 meter deep was completed through the moraine to limit the surface elevation rise of the lake. The terminus in the 360 degree shot in Google Earth a snapshot of which is seen below, indicates the width of the glacier at the terminus is small and the terminus is quite steep, which given the thin nature of the ice, indicates a steep slope under the glacier, not a continuation of the lake basin.. The retreat of this glacier parallels the retreat of other nearby glaciers Llaca Glacier and Artesonraju Glacier
Quelccaya Ice Cap is in the of Peru. The first detailed investigations were by Lonnie Thompson at Ohio State examining the ice cap for its potential for ice coring (Thompson, 1980). Three decades later he is still involved in research on this ice cap and others, which combined have yielded one of the finest glacier climate records we have. This is nicely chronicled in Thin Ice by Mark Bowen. This research generated an excellent ice core record, that has annual resolution back some 1000 years, that illustrated the global nature of the Little Ice Age (Thompson et al, 1986). This core also indicated the reduced accumulation during El Nino events Thompson et al (1984) In conducting this research Thompson et al (2011) Figure 8, has also chronicled the retreat of one outlet glacier the Qori Kalis and put this in context with other tropical glaciers. The retreat of this glacier had been 1300 meters from 1963-2005. Today the University of Massachusetts, Climate System Research Center has installed weather stations on the glacier. Recent fieldwork has also focussed on ablation, accumulation and energy balance measurements, this is nicely chronicled in photographs by Carsten Braun, slideshow bottom of linked page Westfield State University. This post will focus on the development of new proglacial lakes at the terminus of the Quelccaya Ice Cap southwest of Qori Kalis and on the retreat of the ice cap from several lakes that had been in contact with the terminus. Landsat imagery from 1991 and 2010 is used. Point A is Qori Kalis, Point B, C and D are separate termini.
We see several new proglacial lakes indicated by blue arrows and two lakes that were in contact with the ice cap in 1991, but now are not, red arrows. Qori Kalis (point A) has retreated out of its proglacial lake. The glacier filled this lake in 1963, the lake is now 1300 meters long and the glacier is 1450 meters from the northwest end of the lake, this represents its retreat over the last half century. The next lake indicated by a red arrow south of Point A. was in contact with the ice cap in 1991 it is now 200-250 meters from the ice cap edge. The next lake to the south indicated by a red arrow is was also in contact with the ice cap in 1991 and is now 250 meters from the ice cap margin. Points B,C, and D point two newly formed lakes filling basins exposed by glacier retreat since 1991. The distance from the far edge of each lake to the current ice cap margin indicate retreat of 300 m at C, 400 m at D and 250 meters at B.
Artesonraju Glacier is a 3.3 km long glacier in the Cordillera Blanca of Peru drains west from Nevado Artesonraju.Updated July 2015 at
The glacier feeds both Lake Artesonraju, a new lake that formed after 1930 and Lago Paron. The two lakes are dammed by glacier moraines and together have posed a hazard of a glacier dammed lake outburst. In 1951 an outburst of water and alluvium traveled from the upper Artesonraju Lake into Lago Paron, raising the water level in Paron causing downstream flooding and concern about the strength of its moraine dam.
There are numerous moraine dammed lakes in Peru, the dams are just comprised of gravel, sand and clay dumped by the glacier. High water levels caused by upstream floods, avalanches or landslides can cause failure of these moraine dams and down stream flood damage prompted the Peruvian government to develop a strategy to address the problem. They began in the by building tunnels, concrete pipes, through the moraine to allow drainage to a safe level, they then rebuilt the moraine over the drainage system and strengthened it. Since development these systems have worked preventing serious flood issues from the lakes. At Lago Paron a hydropower project has been built that is fed by the tunnel drainage system and Lago Paron has been partially drained to service the hydropower facilities needs. The hydropower faility is owned by Egenor, owned largely by Duke Energy. The lake level has declined substantially by 2003 as the trimline indicates in the image above. This had led to a battle over water resources with local farmers. This Artesonraju Glacier that is the principal feeder to the two lakes retreated 1140 meters from 1932-1987 and by 2004 had retreated another 200 meters. From 2003 to 2013 the glacier continued to retreat and the terminus to narrow. An expanding lake at the terminus is evident in the Google Earth images of 2003 and 2012, pink arrow. A melt pond has also drained at the yellow arrow as the glacier thinned. In the 2013 Landsat image the terminus has further narrowed.
2003 Google Earth image
2012 Google Earth image
2013 Landsat Image
This is 30% of its length gone in the last 75 years.The lower section of the glacier is flat, uncrevassed and is continuing to thin and melt. The upper reaches of the glacier are heavily crevassed indicating continued vigorous flow fed by healthy accumulation on the flanks of Nevado Artesonraju and Nevado Piramide. The equilibrium line of this glacier is at 5150 m, investigations by the Tropical Glaciology Group, Innsbruck, Austria and Hydrology Resources and Glaciology group in Huarez, Peru. In 2005, the surface on many parts of the flat tongue showed that sublimation is important to the mass balance when short wave radiation is limited, and short wave radiation dominates melting during the day.
A new book by Mark Carey, In the Shadow of Melting Glaciers, examines the history of the impact of these glaciers on Andes towns in the Cordillera Blanca.