Benito Glacier, Chile Retreats 2km 1987-2015

On April 28, 2017May 1, 2024 By mspeltoIn chile glacier melt, chile glacier retreat

Benito Glacier comparison in 1987 and 2015 indicating the terminus position in 1987 red arrows, yellow arrows the 2015 terminus positions, purple arrows where glacier thinning is expanding bedrock areas, the snowline is indicated by purple dots.

Glacier Benito is a temperate outlet glacier on the west side of the North Patagonian Icefield the glacier is south of Fraenkel Glacier and north of Acodado Glacier. Loriaux and Casassa (2013) examined the expansion of lakes of the Northern Patagonia Ice Cap. From 1945 to 2011 lake area expanded 65%, 66 square kilometers. Willis et al (2012) noted a 2.0 m ice thickness loss per year from 2001-2011 in the ablation zone. Mouginot and Rignot (2015) indicate that the velocity of Benito Glacier is between 200-500 m per year along the center line below the snowline. Glasser et al (2016) note that this glacier has limited debris cover. In the last two years an expedition organized by Martin Sessions has been examining Benito Glacier and has been reporting from the field this month.

Benito Glacier in 1987 terminated on an outwash plain. The glacier has five key distributary termini two of which have open proglacial lakes. By 2015 there are six tributary termini, five ending in lakes, with one having retreated out of a lake basin. The two tributaries to the north indicated with arrows each retreat approximately 1 km from 1987 to 2015 and in both cases are no longer calving termini. The main glacier terminus has retreated into a proglacial lake, with a retreat of 2 km from 1987 to 2015. The lowest 1.5 km has a low slope and peripheral lakes suggesting the terminus lake will expand substantially as Benito Glacier retreat continues. The transient snowline in the two images 2015 and 2016 is at 900 m. Glasser et al (2016) note that this glacier average transient snowline in 2013-2016 is at 1000 m. Winchester et al. (2013) identified thinning of 150 m in the lower ablation zone from 1973-2011, with the most rapid thinning from 2007-2011.

Benito Glacier comparison in 1987 and 2015 indicating the terminus position in 1987 red arrow, yellow arrow the 2015 terminus positions, and the snowline is indicated by purple dots.

Google Earth image in 2012 of Benito Glacier indicating proglacial lake areas at the green arrows.

Dama Blanca Glacier Retreat, Southern Chile

On April 3, 2017May 1, 2024 By mspeltoIn chile glacier melt, chile glacier retreat, climate change glacier retreat

Dama Blanca Glacier in Landsat images from 1986 and 2017. Red arrow is the 1986 terminus, yellow arrow the 2017 terminus, purple dots the snowline and purple arrows a bedrock ridge.

Dama Blanca Glacier drains west from Chile’s Sarmiento de Gamboa Range in Southern Patagonia. terminating in Lago Verde in the Alacalufes National Reserve. Alacalufes NR features kelp rich fjords, Northofagus coastal forests and glacier clad alpine zones. Davies and Glasser, (2012) indicated extensive recession of almost all glaciers in the range from 1870-2011. They indicate the fastest recession rate of Dama Blanca is from 1986-2001. This range is between the Southern Patagonia Icefield to the north and the Cordillera Darwin Icefield to the south. Incognita Patagonia has been exploring and mapping glaciers in the region since 2015, and have provided a map shown below in coordination with Camilo Rada and Natalia Martinez of the UNCHARTED project . On Marinelli Glacier, in the Cordillera Darwin Icefield, Koppes et al (2009) indicated a retreat of 13 km from 1960 to 2005. More recently Marinellli Glacieri retreated ~3.75 km from 1998 to 2014. Melkonian et al (2013) observed that the Cordillera Darwin Icefield had an average thinning rate of −1.5 m w.e/year with more rapid losses north and west. This is a continuation of the trend noted by Holmund and Fuenzelida (1995) that glaciers on the northern side have a trend of receding fronts. On the southern side the present extent of some glaciers are similar to their 20th century maximum extents. The region is characterized by strong climatic gradients, with high rates of precipitation on the southwestern side of the range where glaciers are faring better and drier conditions on the northern side. Given that the Sarmiento de Gamboa Range is north of Cordillera Darwin it would be expected this area would have substantial recession.

Here we compare satellite images from 1986-2017 to determine the changes of Dama Blanca Glacier. In 1986, the glacier terminated at the end of a peninsula on the south side of Lago Verde, red arrow. The snowline was at 500m. In 2013 the terminus has retreated significantly from the peninsula and the snowline is at 650 m. By 2017 the terminus has retreated 700 m since 1986. The snowline is obscured by clouds in the Landsat image. In February 2017 the snowline is at 700 m. There is also expansion of a bedrock rib on the west side of the glacier that extends to 800 m, purple arrow. The glacier remains actively crevassed to the glacier front as illustrated by the Google Earth image. The glacier will continue to retreat as long as calving continues; however, there is an increase in slope 200-300 m from the current glacier front suggesting the limit for lake development. Izagirre (2017) and the UNCHARTED project explored a number of glaciers in the Sarmiento de Gamboa Range this spring, that will lead to a detailed current map. The retreat here is similar to that of Balmaceda Glacier.

Dama Blanca Glacier in Landsat imags from 2013 and Sentinel image from Dec. 2016 Red arrow is the 1986 terminus, yellow arrow the 2017 terminus, purple dots the snowline and purple arrows a bedrock ridge.

Map from the UNCHARTED Project indicating glaciers of the Sarmiento de Gamboa Range and exploration routes.

Google Earth image of Dama Blanca Glacier in 2013, with the 1986 terminus position at the red arrow.

Erasmo Glacier, Chile Terminus Collapse

On January 17, 2017May 1, 2024 By mspeltoIn chile glacier melt, chile glacier retreat

Erasmo Glacier, Chile, comparison in 1987 and 2016 Landsat images. The red arrow indicates the 2016 terminus and the yellow arrow the 1987 terminus location. Purple dots indicate the snowline and purple arrows locations of upglacier thinning.

Cerro Erasmo at 46 degrees South latitude is a short distance north of the Northern Patagonia Icefield and is host to a number of glaciers the largest of which flow northwest from the mountain. This is referred to as Erasmo Glacier with an area of ~40 square kilometers. Meltwater from this glacier enters Cupquelan Fjord, which is host to farmed salmon. This remote location allows Cooke Aquaculture to protect its farm from environmental contamination. Runoff from Erasmo Glacier is a key input to the fjord, while Rio Exploradores large inflow near the fjord mouth limits inflow from the south. Davies and Glasser (2012) mapped the area of these glaciers and noted a 7% decline in glacier area from 1986-2011 of Cerro Erasmo. The recent retreat of the largest glacier in the Cerro Erasmo massif indicates this area retreat rate has increased since 2011. Paul and Molg (2014) observed a more rapid retreat in general of 25% total area lost from glaciers in the Palena district of northern Patagonia from 1985-2011, a region at 43-44 south, north of Cerro Erasmo.

In 1987 Erasmo Glacier had a land based terminus at the end of a 6 km long low sloped valley tongue. The snowline was at 1100 m. In 1998 there is thinning, but limited retreat and the snowline is at 1250 m. In 2001 a lake has still not formed and retreat is less than 500 m since 1987. By 2013 a proglacial lake has formed and there are numerous icebergs visible in the lake. The snowline is at 1200-1250 m in 2013 at the top of the main icefall. In 2015 a large lake has formed and the snowline is at 1200 m again at the top of the icefall. By 2016 the terminus has retreated 2.9 km since 1987 generating a lake of the same length. The collapse is ongoing as indicated by large icebergs in the lake. The snowline in 2016 is at 1200 m at the top of the icefall The purple arrows indicate locations of expanded bedrock amidst the glacier since 1987. Each location is above 1000 m indicating upglacier thinning and reduced retained snow accumulation is driving the retreat. The west most purple arrow indicates where a glacier formerly was joined to the Erasmo Glacier and is now separated. The retreat is consistent with retreat documented at Reichert Glacier, Hornopirén Glacier and Cord.illera Lago General Carrera Glacier. The rapid retreat will continue until the head of the developing lake basin is reached.

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Hornopirén Glaciers, Chile in Spectacular Retreat

On November 28, 2016May 1, 2024 By mspeltoIn chile glacier melt, chile glacier retreat

Landsat comparison of Rio Blanca Glaciers in Hornopirén National Park, Chile from 1985 to 2016. Red arrow 1985 terminus, yellow arrow 2016 terminus, purple dots the snowline and purple arrows expanding bedrock areas amidst the glacier.

Hornopirén National Park is in the Los Lagos region of Chile. The park is host to a number of glaciers that are in rapid retreat. Davies and Glasser (2012) mapped the area of these glaciers with 113 square kilometers in 1986 and 96 square kilometers in 2011. The retreat of the largest glaciers in the park is nothing short of spectacular in recent years. Here we examine Landsat imagery to identify changes in two or the larger valley glaciers from 1985-2016. These glaciers from the headwaters of the Rio Blanco and are designated Rio Blanco North (RBN) and Rio Blanco South (RBS). Rio Blanco enters the ocean just east of the community of Hornopirén.

In 1985 the two glaciers merged just before the western terminus of the icefield at 820 m, red arrow. The snowline was at 1300 m. There is also an eastern outlet of RBN, terminating at the north end of a basin, red arrow. By 1998 RBN and RBS had separated by over 1 km with the formation of a new lake at the former terminus. The eastern terminus of RBN has begun retreat and is now ending in a proglacial lake. RBS is developing a nunatak at the purple arrow. The snowline was again near 1300 m. By 2016 RBN has retreated 4.5 km, and now terminates at 1200 m, yellow arrow. The deglaciated valley now hosts three alpine lakes that did not exist in 1985. The eastern terminus of RBN has retreated 1100 m and is still terminating in an expanding alpine lake, yellow arrow. By 2016 RBS had retreated 3.4 km since 1985, terminating at 1180 m, yellow arrow. The nunatak in the lower section of RBS, purple arrow, has continued to expand. RBN has lost 56% of its length since 1985 and RBS 37% of its length.The snowline in 2015 and 2016 is at 1600-1700 m. This leaves only a small percentage of the glacier area above the snowline. The large valley glaciers that just 30 years dominated the headwaters of Rio Blanco have lost much or their area and will soon be small slope glaciers clinging to the highest peaks. Retreat here is more extensive than seen 100 km to the northwest at Calbuco Volcano and for the Northern Patagonia Icefield.

Landsat comparison of Rio Blanca Glaciers in Hornopirén National Park, CVhile from 1998 to 2015. Red arrow 1985 terminus, purple dots the snowline and purple arrows expanding bedrock areas amidst the glacier.

East Terminus of Rio Blanca North, with the newly formed lake. This terminus is above 1300 m and has retreated largely via iceberg calving.

RG150-17.01019 Glacier Retreat, Southern Patagonia Forms Lake

On November 21, 2016May 1, 2024 By mspeltoIn chile glacier melt, chile glacier retreat

Retreat of RG150 indicated in Landsat images from 1984, 2001 and 2015. Red arrow indicates 1984 terminus and yellow arrow 2015 terminus.

RG150 is a 3.5 km long glacier in Bernardo O’Higgins National Park on the western edge of the Southern Patagonia Icefield, Chile. RG150 is an unnamed glacier given this designation as part of the Randolph Glacier Inventory. The glacier terminates in a lake that drains into Seno Andrew. Willis et al (2012) observed that between February 2000 and March 2012 that the Southern Patagonia Icefield is rapidly losing volume and that thinning extends even to high elevations. The mass balance loss is occurring at a rate of −20.0 ± Gt/year, which is +0.055 mm/year of sea level rise. The retreat has been driven by increasing calving rates from the 1975-2000 to the 2000-10 period (Schaefer et al, 2015). The pattern of retreat is consistent between these glaciers and the region as noted by Davies and Glasser (2012), annual rates of shrinkage in the Patagonian Andes increased in from 0.10% year from 1870-1986, 0.14% year from 1986-2001, and 0.22% year from 2001-2011. Davies and Glasser (2012), note the all the glaciers in the complex inclusive of RG150 had their fastest retreat period from 2001-2015. Glasser et al (2016) observed both an increase in glacier proximal lakes and in debris cover on glaciers with glacier retreat from 1987-2015. These losses have led to retreat such as at Balmaceda Glacier, Glaciar Marconi and Glacier Onelli. Here we examine Landsat imagery from 1984 to 2015 to identify glacier change and the formation of a new lake.

In 1984 there was no glacier lake at the terminus, with the lower 1 km of the glacier being a low sloped glacier tongue. By 2001 a small proglacial lake had developed 250-300 m long. In 2005 the glacier retreat had led to continued lake expansion. The glacier had filled the lake with numerous small icebergs. By 2015 the glacier still terminates in the proglacial lake that is not 850-900 m long. The glacier retreat of 850 m since 1984 is 20-25% of the total glacier length. The low slope region is minimal in length in 2015 indicating the lake basin is almost complete. This will lead to a reduced rate of retreat. This is a very cloudy region, and the images here are not at the end of the melt season. Hence, the equilibrium line altitude can be ascertained. At the crest of the glacier 1300 m, there are a number of wind sculpted features that are 400-600 m long, attesting to the strong westerly winds in the region. RG150 has significant retained accumulation each year and can survive the current climate.

Retreat of RG150 indicated in Google Earth images from 2005 and 2015. Red arrow indicates 1984 terminus and purple arrows indicate wind features at the top of the glacier.

RG150 in Google Earth image looking upglacier in 2015. Red arrow indicates 1984 terminus and yellow arrow 2015 terminus and purple arrows indicate wind features at the top of the glacier.

Bernardo Glacier, Patagonia, Chile Accelerated Retreat in Expanding Lake Complex

On May 23, 2016May 2, 2024 By mspeltoIn chile glacier melt, chile glacier retreat, climate change glacier retreat, glacier climate change, Glacier Observations1 Comment

Comparison of 1986 and 2015 Landsat image of Bernardo Glaciers three termini, north, main and south. Red arrows indicate 1986 terminus location and yellow arrows the 2016 terminus location. Indicating the substantial retreat of each terminus and lake expansion for the north and main terminus, while the lake drained at the southern terminus.

Bernardo Glacier is a difficult to reach outlet glacier on the west side of the Southern Patagonia Icefield (SPI). It The glacier currently ends in an expanding proglacial lake system, with three primary termini. Here we examine changes from 1986 to 2016 using Landsat images. Willis et a (2012) quantify a rapid volume loss of the SPI from 2000-2012 of 20 giga tons per year mainly from rapid retreat of outlet glaciers. They note a thinning rate of 3.4 meters per year during this period of the Bernardo Glacier region. Mouginot and Rignot (2014) illustrate that velocity remains high from the terminus to the accumulation zone on Bernardo Glacier. They also indicate the accumulation zone does not extend as far east toward the crest of the SPI as previously mapped. Davies and Glasser (2012) indicate that over the last century the most rapid retreat was from 2000 to 2011.

In 1986 Bernardo the southern terminus of the glacier was nearly in contact with Tempano Glacier. The main terminus primarily ended on an outwash plain with a small proglacial lake developing. The northern terminus had retreated a short distance south from a peninsula. By 1998 the northern terminus had retreated into a wider, deeper lake basin, filled with icebergs. The main terminus is still mainly grounded on an outwash plain. A small lake has developed between Bernardo Glacier and Tempano Glacier to the south. By 2003 the northern terminus had retreated 2 km from 1986, the main terminus 1.5 km and the southern terminus 1.2 km. By 2015 the lake between Tempano and Bernardo Glacier had drained. The main terminus had retreated 1.5 km since 1986. In 2016 the northern terminus had retreated 3.5 km since 1986, the main terminus 2.5 km and the southern terminus 2.75 km. The largest change is the loss of the lake between Tempano and Bernardo Glacier which slow the retreat of the southern terminus. If this terminus retreat into the another lake basin that shared with the main and north terminus, this would likely destabilize the entire confluence region. The nearly 1 km retreat in a single year from 2015 to 2016 of the main terminus indicates the instability that will lead to further calving enhanced retreat. The retreat of this glacier fits the overall pattern of the SPI outlet glaciers, for example Chico Glacier and Lago Onelli Glaciers

1998 Landsat image. Red arrows indicate 1986 terminus location and yellow arrows the 2016 terminus location.

2003 Landsat image. Red arrows indicate 1986 terminus location and yellow arrows the 2016 terminus location. Main terminus beginning to retreat from outwash plain.

2015 Landsat image. Red arrows indicate 1986 terminus location and yellow arrows the 2016 terminus location. Note the considerable difference in main terminus versus one year later in 2016.

Glacier Nef, Patagonia, Chile retreat 1987-2016.

On May 10, 2016May 2, 2024 By mspeltoIn chile glacier melt, chile glacier retreat, Chile glaciers and hydropower

Comparison of 1987 and 2015 Landsat images of Nef Glacier at right and Cachet Glacier at left. Indicating retreat of Nef Glacier from red arrows to yellow arrows of 1.8 km and development of a new lake at the terminus. Purple arrows indicate upglacier thinning leading to separation of glacier tributaries.

Glacier retreat and thinning is particularly strong in the Patagonian icefields of South America. The two largest temperate ice bodies of the Southern Hemisphere are the Northern Patagonia Icefield 4,000 km2 and the Southern Patagonia Icefield, 13,000 km2. It has been estimated that the wastage of the two icefields from 1995–2000 has contributed to sea level rise by 0.105 ± 0.011 mm year,which is double the ice loss calculated for 1975-2000 (Rignot et al. 2003). Davies and Glasser (2012) work, has an excellent figure indicating two periods of fastest recession since 1870, are 1975-1986 and 2001-2011 for NPI glaciers, which suggests that ice volume loss increased after 2000. They noted the loss was 0.07% from 1870-1986, 0.14% annually from 1986-2001 and 0.22% annually from 2001-2011. Glasser et al (2011) find the recent ice volume rate loss is an order of magnitude faster than at other time intervals since the Little Ice Age. Baker River (Rio Baker) is located to the east of the Northern Patagonia Icefield and is fed mainly by glacier melt water originating from the eastern outlet glaciers of the icefield Leones, Soler, Nef, Colonia. Rio Baker is the most important Chilean river in terms of runoff, with an annual mean discharge of about 1000 m3/s Lopez and Casassa (2009). Glacier Nef is one of the main glaciers feeding Rio Baker. Rio Baker was a proposed critical hydropower resource for Chile. Hidroaysen Project had proposed 5 dams on the Baker and Pascua River generating 2750 MW of power, all three proposed dams on the Rio Baker have been cancelled.

Glacier Nef began to retreat into a moraine dammed proglacial lake in 1945 (Loriaux and Casassa, 2014). By 1987 the lake remained less than 1 km long, with glacier thinning predominating over retreat. From 1987 to 2015 the glacier has retreated 1.8 km calving into the growing lake. The lake width was essentially uniform during this phase of retreat There is not significant retreat from 2015 to 2016. The lake is currently about 5.4 square kilometers and has a mean depth of ~125 m (Loriaux and Casassa, 2014). In 2015 Glacier Nef has not reached the head of this proglacial lake and will continue to retreat. The west side of the terminus is debris covered and has a fringing proglacial lake that has developed after 2000 and will aid in the continuing retreat. The terminus is currently at a pinning point, where the valley is constricted providing greater terminus stability. Further retreat will lead to an expansion of the embayment and calving front, leading to a further increase in glacier retreat. The lack of elevation change of the lower glacier and the isolated proglacial lake here suggests the lake will expand laterally as well as in length. The debris cover is slowing the thinning and retreat of the western margin. The purple arrows indicate thinning upglacier in a former tributary glacier. The 2016 Landsat image indicates a high snowline at 1350 m, purple dots. Willis et al (2011) observed that the thinning rate of NPI glaciers below the equilibrium line has increased substantially from 2000-2012, partly an indication of a higher snowline indicative of greater ablation and a longer snow free period lower in the ablation zone. For example on Nef Glacier by January 8, 2016 the snowline was at 1300 m and remained high up until at least the mid-march image below. The retreat follows the pattern of enhanced calving in a proglacial lake for NPI glaciers such as Gualas Glacier, Reichert Glacier, Steffen Glacier, and Colonia Glacier.

2016 Landsat image of Nef Glacier indicating terminus yellow arrow and source of the debris for the debris covered terminus.

Closeup of Nef Terminus from Chile Topographic Application. Notice the widening valley just above terminus. Debris cover is insulating ice on west side of terminus.

San Quintin Glacier, Chile terminus disintegration 1987-2015

On February 15, 2016May 2, 2024 By mspeltoIn chile glacier melt, chile glacier retreat, climate change glacier retreat2 Comments

Landsat comparison of San Quintin Glacier in 1987 and 2015: red arrow indicates 1987 terminus location, yellow arrow indicates 2015 terminus location of the three main termini, and the purple arrow indicates upglacier thinning.

San Quintin is the largest glacier of the NPI at 790 km² in 2001 (Rivera et al, 2007). The glacier extends 50 km from the ice divide in the center of the ice cap. The peak velocity is 1100 m/year near the ELA (Rivera et al 2007), declining below 350 m/year in the terminus region. The velocity at the terminus has increased from 1987 to 2014 as the glacier has retreated into the proglacial lake (Mouginot and Rignot, 2015). The high velocity zone extends more than 40 km inland an even greater distance than at San Rafael (Mouginot and Rignot, 2015). Thinning rates in the ablation zone of the glacier are 2.3 m/year (Willis et al, 2012). The glacier has a low slope rising 700 m in the first 22 km. The low slope, broad piedmont lobe and many distributary terminus lobes is like the Brady Glacier, Alaska.

Davies and Glasser (2012) note that San Quintin Glacier terminated largely on land until 1991. The glacier has lost 15 % of its area in the last century (Davies and Glasser, 2012). The glacier has a main terminus and many subsidiary termini. In 1987 it is a piedmont lobe with evident minimal marginal proglacial lake development beginning. There is limited lake development at the main southern and northern terminus Point C and B respectively. Harrison et al (2001) observed that in 1993 the glacier terminus was advancing strongly into vegetated ground, while from 1996 to May 2000 the glacier underwent a transition between advance and retreat. The high rates of thinning are leading to the retreat not just of main terminus but the distributary terminus areas extending north and south into lake basins from the main glacier. From 1987 to 2015 the main terminus retreated 2200 m, almost all after 2000, largely through a disintegration of the terminus tongue in a proglacial lake. Extensive rifting of the terminus lobe in 2013 and 2015 is still apparent in imagery below, indicating this rapid area loss is not finished. The main lake, Point A, had an area of 23.8 square kilometers in 2011 (Loriaux and Cassasa, 2013) . The lake at Point B developing on the north side of the glacier, due to a 3500 m retreat, is now over 8 square kilometers. The southern terminus at Point C, has a narrow fringing lake and a retreat of 1100 meters from 1987-2015. The retreat here follows the pattern of Fraenkel Glacier, Acodado Glacier and Steffen Glacier to the south.

Digital Globe image of San Quintin Glacier in 2011.

2013 Google Earth image, with the large rifts indicating glacier weakness noted with blue arrows.

2015 Landsat image, yellow line indicates terminus. Note the tongue is surrounded on three sides by water.

Balmaceda Glacier Retreat, Chile Releases Island

On January 21, 2016May 2, 2024 By mspeltoIn chile glacier melt, chile glacier retreat, Chile glaciers and hydropower

1986 and 2015 Landsat images of the Balmaceda Glacier, Chile region. Red arrow indicates 1986 ice front, yellow arrow 2015 ice front and purple arrow a tributary that has detached.

Balmaceda Glacier (Felicia Glacier) is at the southeastern end of the Southern Patagonia Ice Cap (SPI) field and drains into the Serrano River. There is another glacier referred to as Balmaceda that descends steeply almost to the shores of Fiordo Ultima Esperanza, hence Felicia Glacier will be used here. Willis et al (2012) observed that between February 2000 and March 2012, indicate that SPI is rapidly losing volume, that thinning extends to the highest elevations. The mass balance loss is occurring at a rate of −20.0 ± Gt/year, which is +0.055 mm/year of sea level rise. The retreat is driven by increasing calving rates from the 1975-2000 to the 2000-10 period (Schaefer et al, 2015). The pattern of retreat is consistent between these glaciers and the region as noted by Davies and Glasser (2012), annual rates of shrinkage in the Patagonian Andes increased in from 0.10% year from 1870-1986, 0.14% year from 1986-2001, and 0.22% year from 2001-2011. These losses have led to retreat such as at Glaciar Marconi and Glacier Onelli

In 1986 the glacier terminated on an island in that acts as pinning point stabilizing the glacier front. The calving front is over 2.5 km wide. By 2000 Landsat imagery indicates the glacier has retreated from the island with the greatest retreat on the north side. By 2013 the glacier has receded into a narrow western arm of the lake, the snowline is at 600 m. By 2015 a southern tributary has separated from the main glacier at the purple arrow. The terminus at the yellow arrow is 1 km from an increase in surface slope indicating a rise in bedrock that may be the inland margin of the lake. The retreat from 1986 to 2015 is 2100 m and the current calving front is 1.2 km wide. The snowline in 2015 is at 1000 m is quite high. De Angelis (2014) notes the ELA for this glacier at 690 m. Above the snowline the linear wind sculpted features oriented west to east indicate the ferocious winds of the region Schaefer et al (2015) note the exceptional accumulation rates in the region

The Balmaceda Glacier drains into the Serrano River, the headwaters being Del Toro Lake on the southern boundary of Torres del Paine National Park. The river is home to numerous giant Chinook salmon which can weigh up to 35 kg with fishing season from June to December. Chinook salmon have just recently started populating rivers in Chile and Argentina. Fish hatcheries in southern Chile release thousands of Chinook smolts. The introduced Chinook originate from tributaries of the Columbia River of Washington and Oregon.

2000 Landsat Image

2013 landsat image

2015 Landsat image the purple dots are the snowline which at 1100 m is quite high. Also note the long wind drift features extending west to east above the snowline.

Colonia Glacier, Chile Retreat and Periodic Lake Outbursts

On October 13, 2015May 2, 2024 By mspeltoIn chile glacier melt, chile glacier retreat, Chile glaciers and hydropower, climate change glacier retreat

Comparison of 1987 and 2015 Landsat images indicating retreat from red arrows to yellow arrows of 2.5 km and development of a new lake at the terminus. orange arrow indicates glacier dammed lake that fills and empties periodically.

Colonia Glacier drains east from the Northern Patagonia Icefield feeding the Baker River, Chile. It is the largest glacier draining east from the NPI. A comparison of the 1987 and 2015 images indicate a 2.5 km retreat of the glacier front, development of a large lake and areas of thinning well upglacier at the purple arrows. The recent substantial retreat of Colonia Glacier like Glacier Nef just to its north is posing new hazards. The glacier is unusual in the number of lakes that are adjacent to or feed into the adjacent glacier dammed or proglacial lakes. In the image below Lake A=Arco Lake, Lake B=East Terminal Lake, Lake C=Cachet 1 , Lake D= West terminal Lake, Lake E=Colonia Lake and Lake F=Cachet 2. In the case of Baker River the outburst floods are a threat to the planned hydropower developments as documented by Dusaillant and others (2009). Hidroaysen Project proposed 5 dams on the Baker and Pascua River generating 2750 MW of power that after initial permit approval in 2011Chile’s Committee of Ministers overturned the environmental permits in 2015.

Google Earth image from 2005.

The glaciers recent retreat and glacier lake outburst floods have been closely monitored by the Laboratorio de Glaciología in Valdivia, Chile. Aniya and others (1999) observed that Colonia Glacier began a rapid retreat after 1985 from 1997-2005 that has further accelerated, with a general frontal retreat of 2 km. Rivera and others (2007) observed that the Colonia Glacier had lost 9.1 square kilometers of area from 1979-2001, which is 3% of the total glacier area and thinned 1.1 m per year in the ablation zone.

Image from Laboratorio de Glaciologia, frontal change 1944-2005.

The Laboratorio de Glaciologia’s observed in the spring of 2008 Baker River suddenly tripled in size, in less than 48 hours, roads, bridges, and farms were severely damaged. Lake Cachet 2 had vanished the 5 square kilometer glacial lake had emptied 200 million cubic meters of water in just a matter of hours. This lake drained beneath the glacier after sufficient water had filled the lake to buoy part of the glacier and subglacial conduits had begun to develop. Since Cachet 2 emptied in April 2008, the lake has emptied at least six more times October, December 2008, March and September 2009, March 2010, and early 2013 with peak flows released of 3000 cubic meters per second. Below are images of Cachet 2 full iand empty in 2008 from Laboratorio de Glaciologia’s. Also a comparison of before and after drainage in Landsat images from Sept. 2012 and Feb. 2013.

Cachhet Lake full looking toward Colonia Dam 2008

Cachet Lake after emptying looking upvalley away from Colonia Glacier 2008.

Cachet lake full in Sept. 2012 and emptied in Feb. 2013 Landsat images.

The two lakes at the terminus of the glacier did not exist in 1979, the western most terminus lake drained into the easternmost terminus lake (D) via a sub-glacial tunnel after formation in the late 1980’s until 2005 when a channel was cut right through the glacier terminus. Retreat of the glacier terminus first led to significant lake development in 2001. This is evident in the image below, there is still glacier ice on both sides of this drainage channel. By 2015 the lakes have merged into a single large proglacial lake at the terminus that is 3.2 km wide.The development and demise of glacier dammed lakes and the resultant problem of glacier lake outburst floods is not rare today, Imja Glacier, and Tulsequah Glacier are other examples.

Lake expansion at the end of the Colonia Glacier from 2005 to 2013, Google Earth images.

Acodado Glacier, Chile Rapid Retreat 1987-2015

On September 21, 2015May 2, 2024 By mspeltoIn chile glacier melt, chile glacier retreat, climate change glacier retreat, glacier climate change, Glacier Observations

Landsat image comparison 1987 and 2015
Loriaux and Casassa (2013) examined the expansion of lakes of the Northern Patagonia Ice Cap. From 1945 to 2011 lake area expanded 65%, 66 square kilometers. Rio Acodado has two large glacier termini at its headwater, HPN2 and HPN3. that are fed by the same accumulation zone and comprise the Acodado Glacier. The glacier separates from Steffen Glacier at 900 m. The lakes at the terminus of each were first observed in 1976 and had an area of 2.4 and 5.0 square kilometers in 2011. (Loriaux and Casassa, 2013). Willis et al (2012) noted a 3.5 m loss per year from 2001-2011 in the ablation zone of the Acodado Glacier, they also note annual velocity is less than 300 m/year in the ablation zone. Davies and Glasser (2012) noted that the Acodado Glacier termini, HPN2 and HPN3, had retreated at a steadily increasing rate from 1870 to 2011. Here we examine the substantial changes in Acodado Glacier from 1987 to 2015 using Landsat imagery.
Digital Globe image of Acodado Glacier and the termini HPN2 and HPN3.

In HPN2 terminates at the red arrow in 1987 and HPN3 at the yellow arrow, the snowline is at the purple dots at 1000 m. By 2000 the glacier has retreated from the red and yellow arrow by 400 m and 900 m respectively, and the snowline is at 1100 m. In 2014 there are many large icebergs in the lake at the terminus of HPN3, these are from recent calving retreat. This is not an area where the lakes develop even seasonal lake ice cover. The snowline is again at 1100 m. In 2015 it is apparent that HPN2 has retreated 2100 m from the red arrow to the pink arrow. HPN3 has retreated 3200 m from the yellow to the orange arrow. The snowline is again at 1100 m. The retreat accelerated after 2000 for both glaciers. This high of a snowline indicates warm temperatures generating high ablation rates, which will lead to more retreat. HPN3 has a sharp rise in elevation 2.5 km above the terminus, before it joins the main Acodado Glacier, it should retreat rapidly toward this point and then calving will end and retreat will slow. The retreat here is synonymous with the pattern observed at other Northern Patagonia Ice Cap outlet glaciers each with rapid calving retreats in expanding proglacial lakes; Fraenkel Glacier, Gualas and Reichert Glacierand Steffen Glacier.

Landsat image from 1987

Landsat image from 2000

Landsat image from 2014

Landsat image from 2015

Fraenkel Glacier Retreat, Patagonia, Chile

On September 17, 2015May 2, 2024 By mspeltoIn chile glacier melt, chile glacier retreat, glacier climate change, Glacier Observations

Fraenkel Glacier drains the west side of the Northern Patagonia Ice Cap (NPI) just south of Glaciar San Quintin. The retreat of this glacier in the last 30 years mirrors that of Gualas and Reichert Glacier, which also terminate in an expanding proglacial lake. Davies and Glasser (2012) work, had an excellent Figure indicating two periods of fastest recession since 1870, are 1975-1986 and 2001-2011 for NPI glaciers. They noted the loss was 0.07% from 1870-1986, 0.14% annually from 1986-2001 and 0.22% annually from 2001-2011. Willis et al (2011) observed that the thinning rate of NPI glaciers below the equilibrium line has increased substantially from 2000-2012. On Fraenkel Glacier they observed a 2.4 m per year thinning in the ablation zone. Here we examine the changes in this glacier from 1987 to 2015 using Landsat Image.

In 1987 the glacier terminus was at the end of a peninsula red arrow and the proglacial lake it terminates in is 2 km long. There is a medial moraine on the glacier at the yellow arrow and the glacier covers the terrain below an icefall at the purple arrow. By 2000 at the purple arrow bedrock is appearing from the base of the glacier. The medial moraine at yellow arrow is little changed. The terminus has retreated 800 m. By 2015 the area around the purple arrow has been deglaciated emphasizing the amount of thinning in the ablation zone even well upglacier of the terminus. At the yellow arrow the medial moraine has been replaced by a wide rock rib separating the glacier from a former tributary. The main terminus is at the pink arrow, indicating a retreat of 1.4 km since 1987. The retreat rate of 50 meters per years though large is less than on Reichert Glacier or Gualas Glacier. Mouginot and Rignot (2014) observe that Fraenkel Glacier does not have the high velocity of the neighboring Benito and San Quintin Glacier or the Gualas and Reichert Glacier, this leads to the potential for greater mass loss of the ablation zone and even faster retreat.

Fraenkel Glacier Landsat Image 1987

Fraenkel Glacier Landsat Image 2000