Category: chile glacier retreat

Bernardo Glacier, Chile Lake Drainage 2024-Retreat Continues

On By mspeltoIn chile glacier melt, chile glacier retreat, Glacier Observations

Bernardo Glacier in Sentinel images from Dec. 26, 2023 and Feb. 9, 2024 illustrating the drainage of the southern end of the proglacial lake by the northern terminus. The lake was full in 2021, partially drained by Oct. 2022, further drained by March 2023 and did not refill through Sept. 2023. The lake refilled between September and December 2023 . And drained again by Feb. 9,2024. Channel location appears to be at Point C. There is 9 km2 of exposed lake bed.

Bernardo Glacier in Sentinel images from Oct. 16, 2022 and Sept. 17, 2023 illustrating the drainage of the southern end of the proglacial lake by the northern terminus (N). The lake was full in 2021, partially drained by Oct. 2022, further drained by March 2023 and has not significantly refilled by Sept. 2023, still 8 km² of exposed lake bed. 

Bernardo Glacier in Landsat images from 1986 and 2021 illustrating retreat at the southern (S), middle (M) and northern (N) terminus respectively. Red arrows are 1986 terminus locations, yellow arrows are 2021 terminus locations. Separation from Tempano (T) occurs at southern terminus, while lake expansion occurs at M and N.

Retreat of Bernardo Glacier in Landsat images from 2003 and 2015.

In 1986 Bernardo the southern terminus of the glacier was in tenuous contact with Tempano Glacier. The middle terminus primarily ended on an outwash plain with a fringing proglacial lake developing. The northern terminus had retreated a short distance south from a peninsula that had acted as a pinning point. A small lake developed completely separating Bernardo Glacier and Tempano Glacier. By 1998 the northern terminus had retreated into the wider, deeper portion of the lake basin that was now filled with icebergs. In 2015 the northern terminus had retreated 3.5 km since 1986. By 2021 the northern terminus had retreated 4.1 km.  This led to a 7.8 km² lake expansion at the northern terminus, with a total lake area of 17.5 km².

On October 2, 2022 the water level had dropped some, with lake area falling slightly. The lake continued to fall through the summer season of 2023. The lake did not refill through the winter and into the spring, September 2023, with the lake having an area of 9.5 km², and 8 km² of lake bed still exposed. The lake did refill by December 2023, and then drained to an even greater extent then in 2023 as of Feb. 2024. Continue glacier thinning and retreat will reduce the ability of the glacier to continue to dam this lake. Gourlet et al (2016) identify Bernardo Glacier as having thinner ice than other large outlet glaciers such Jorge Montt or O’Higgins, which helps lead to rapid terminus change.

Southern Andean huemel an endemic deer on the foreland beyond Bernardo Glacier (Photograph from Eñaut Izagirre

Bernardo Glacier, Chile Lake Drainage as Retreat Continues

On By mspeltoIn chile glacier melt, chile glacier retreat

bernardo glacier 2022-2023 spring

Bernardo Glacier in Landsat images from Oct. 16, 2022 and Sept. 17, 2023 illustrating the drainage of the southern end of the proglacial lake by the northern terminus (N). The lake was full in 2021, partially drained by Oct. 2022, further drained by March 2023 and has not signficantly refilled by Sept. 2023, still 8 km² of exposed lake bed. 

Bernardo Glacier in Landsat images from 1986 and 2021 illustrating retreat at the southern (S), middle (M) and northern (N) terminus respectively. Red arrows are 1986 terminus locations, yellow arrows are 2021 terminus locations. Separation from Tempano (T) occurs at southern terminus, while lake expansion occurs at M and N.

Bernardo Glacier is an outlet glacier on the west side of the Southern Patagonia Icefield (SPI) that currently ends in an expanding proglacial lake system, with three primary termini.  The northern terminus retreated 4.1 km from 1986-2021 leading to an 8.7 km² lake expansion. Total lake area which had remained filled during this period was Their was a significant drainage of the lake at the north terminus that by late summer of 2023 had left 8 km² of lake bed exposed, and as spring arrives in 2023 has yet to refill.  Davies and Glasser (2012) indicate that over the last century the most rapid retreat was from 2000 to 2011. Willis et a (2012)  note a thinning rate of 3.4 meters per year during this period of the Bernardo Glacier region, which drives the retreat. Eñaut Izagirre conducted fieldwork in this area in 2019 and provided two images from the middle terminus of Bernardo Glacier, see below.

Bernardo Glacier in Landsat images from 1998 and 2020 illustrating retreat at the southern (S), middle (M) and northern (N) terminus respectively. Proglacial lakes not yet signficant in 1998, expansive by 2020. Red arrows are 1986 terminus locations, yellow arrows are 2021 terminus locations. Separation from Tempano (T) occurs at southern terminus, while lake expansion occurs at M and N.

In 1986 Bernardo the southern terminus of the glacier was in tenuous contact with Tempano Glacier.  The middle terminus primarily ended on an outwash plain with a fringing proglacial lake developing.  The northern terminus had retreated a short distance south from a peninsula that had acted as a pinning point. A small lake developed completely separating Bernardo Glacier and Tempano Glacier. By 1998 the northern terminus had retreated into the wider,deeper portion of the lake basin that was now filled with icebergs. In 2015 the northern terminus had retreated 3.5 km since 1986. By 2021 the northern terminus had retreated 4.1 km.  This led to a 7.8 km² lake expansion at the northern terminus, with a total area of 17.5 km². On October 2, 2022 the water level had dropped some, with lake area falling slightly. The lake continued to fall through the summer season of 2023. The lake has not refilled through the winter and into the spring of 2023, with the lake having an area of 9.5 km², and 8 km² of lake bed still exposed. Will the lake refill this summer or drop even further? Gourlet et al (2016) identify Bernardo Glacier as having thinner ice than other large outlet glaciers such Jorge Montt or O’Higgins, which helps lead to rapid terminus change. Other glaciers experiencing singificant retreat in this region of the Souther Patagonia Icefield include Oriental Glacier, Lucia Glacier, and Ofhidro Glacier.

Southern Andean huemel an endemic deer on the foreland beyond Bernardo Glacier (photograph from Eñaut Izagirre).

Middle terminus of Bernardo Glacier in 2019 taken by Eñaut Izagirre who considers this a condor-view

Sentinel images illustrating drop in lake level and resulting lake drainage from Oct. 2, 2022 to Sept. 17, 2023.

Retreat of Bernardo Glacier in Landsat images from 2003 and 2015.

Tyndall Glacier, Chile April 2023 Calving Retreat

On By mspeltoIn chile glacier melt, chile glacier retreat

Tyndall Glacier in Sentinel images from March 11, 2023 and April 12, 2023 indicating the calving event and three icebergs generated.

Tyndall Glacier is a large outlet glacier of the Southern Patagonia Icefield (SPI). This glacier has an area of over 300 km². The main glacier terminus is in Lago Geikie, which began to form around 1940, and the east terminus previously terminated in Lago Tyndall. Laboratorie de Glaciologie reports on both the retreat of this glacier and the Lago Geikie water depth. Extendingaross the middle half of the lake from the 2003 terminus location most of the way to the southern margin  of the lake is a basin that is over 200 m deep.Weidemann et al (2018) indicate a -2.5 m/year mass balance loss for the glacier from 2000-2014, much of the loss resulting from frontal ablation, that has driven the continued thinning and retreat. This thinning has exposed dinosaur fossilson the east margin 12 km upglacier of the terminus (NASA EO, 2022).

Tyndall Glacier change from 1986 to 2023 in Landsat images indicating the retreat and lake expansion from 12 km² to 21 km². Red dots the 1986 termins, yellow dots the 2023 terminus locaiton.

The glacier experienced a significant calving event and associated recession in April 2023, with a 1.5 km² recession from March 11-April 12, 2023. This has increased the area of Lago Geikie to 21 km². In 1986 the area of the lake was 12 km² and the glacier was in contact with Lago Tyndall. Recession had expanded the lake to 17 km² by 2003,  and 18 km² by 2010 when the glacier separated from Lago Tyndall. In 2003 a similar calving event took place as the glacier lost much of its protruding central tongue, see iceberg below. From 2013 to 2022 terminus retreat was limited though thinning continued. In late March or Early April of 2023 first the central terminus tongue broke off as seen on April 5. A significant rift is evident that then led to a larger calving event prior to April 12. Is this the largest calving event in the last two decades for this glacier?  There is a surface steepening within a 1/2 km of the current terminus indicating a reduction in lake depth. Sakakibara and Sugiyama, (2014)report a decelaration of this glacier from 1986-2011 and a retreat rate of ~100 m/year during this interval. The calving event is similar to the breakup of the terminus tongue I noted at Soler Glacier this year. This is a more active front experiencing a calving retreat similar to that of Glacier O’Higgins.

Tyndall Glacier change from 2003 to 2008 in Landsat images indicating the retreat and lake expansion from 17 km² to 18 km².

Tyndall Glacier change from 2013 to 2022 in Landsat images indicating the limited retreat and lake expansion.

Tyndall Glacier on April5, 2023 in Sentinel imagery indicating rift and iceberg.

Soler Glacier, Chile Terminus Tongue Breakup in 2023

On By mspeltoIn chile glacier melt, chile glacier retreat

Soler Glacier, Chile terminus tongues is 1.9 km long on 12-26-2022 and by 3-21-2023 it has broken up, with four larger bergs A-D. False color Sentinel images.

In 2020 I noted that the Soler Glacier “terminus tongue in its lowest 1.5 km continue to thin and will collapse in the lake in the near future.” Here the breakup of this tongue in 2023 is reported. Soler Glacier is an outlet glacier on the east side of the Northern Patagonia Icefield (NPI). The terminus response of this glacier was slower and more limited than on most NPI glaciers, just 200-350 from 1944 to 1984 (Aniya and Fujita 1986).  Glasser et al (2016) note the recent 100 m rise in snowline elevations for the NPI, which leads to the 2 m thinning per year identified by Willis et al, (2012)  in the ablation zone from 1987-2011.  Loriaux and Casassa (2013) examined the expansion of lakes on the Northern Patagonia Ice Cap reporting that from 1945 to 2011 lake area expanded 65%, 66 km2.

Soler Glacier had no proglacial lake in 1987. By 2000 a small lake had developed both on the north and south side of the main terminus with a total area of ~0.3 km2 see Mike Hambrey image below. In 2016  lake had expanded, with the northern arm mostly filled with ice.For Soler Glacier lake formation did not occur until the last decade reaching an area of 1 km² by 2020. As the 2022/23 melt season began the glacier had a 1.9 km long central tongue extending down the middle of the lake, that had an area of 1.4 km², as evidenced on Dec. 26, 2022. By early March the tongue had broken up as revelaed by the Sentinel image on March 21, 2023. On this date the lake surface has refrozen on the south side and has some new snow on it. The lake has expanded to 2.75 km², with the largest iceberg B, occupying 10% of the lake. The lake expansion is small compared to Steffen Glacier or San Quintin Glacier, but just as significant for this smaller glacier.

Soler Glacier in 1987 and 2020 Landsat images.  Red arrow indicates 1987 terminus location, yellow arrow indicates 2020 terminus location on north side of glacier.  Yellow dots indicate margin of lake and purple arrows indicate specific locations where glacier thinning is evident.

Soler Glacier in 2020 and 2023 Landsat images.  Red arrow indicates 1987 terminus location, yellow arrow indicates 2020 terminus location on north side of glacier.  Yellow dots indicate margin of lake and purple arrows indicate specific locations where glacier thinning is evident in 2020.

Mike Hambrey Photograph of Soler Glacier in  2000, illustrating narrow nature of the proglacial lake.

 

Soler Glacier in 2016 Landsat image.  Red arrow indicates 1987 terminus location, yellow arrow indicates 2020 terminus location on north side of glacier. Lake area is still limited.

 

Snowcover Free Glaciers Generates Fragmenting in Central Andes, Chile

On By mspeltoIn chile glacier melt, chile glacier retreat, Chile glaciers and hydropower, Uncategorized

Snowcover free glaciers in the Central Andes in 2014 ad 2023 Landsat images. The ongoing fragmentation and retreat is evident at Point A-H, see closeup details below. The glacier as Point B has melted away, At Point G and H glacier tributaries have separated from the Norte Cipreses Glacier in the valley below. At Point D-F expanding bedrock areas amidst glacier driving further fragmentation. Glaciers at Point A and C rapidly melting away. 

Palomo Glacier and North Cipreses  are three comparatively large glaciers in the Central Andes of Chile. The three glaciers are adjacent to each other with the Palomo and Coton Glacier feeding  the Rio Cortaderal. Rio Cortaderal is part of the Cachapoal River watershed that supplies two Pacific Hydro projects; a 110 MW run of river project at Chacayes and a  78 MW Coya run of river project. Norte Cipreses Glacier feeds the Rio Cipreses. These glaciers are important water resource from December-March Bravo et al (2017) quantified this resource for adjacent Universidad Glacier, which supplied 10-13% of all melt season runoff to the Tinguirica Basin. La Quesne et al (2009) reported that Palomo Glacier retreated 1160 m from 1955-1978 and advanced ~50 m 1987-2007, due tot Palomo Glacier having an equilibrium balance durng the 1987-2000 period. Pelto (2022) reported a retreat of the glacier front of 1250 m from 2002-2022.  Here we examine the changes of this glacier from 2014-2023 using Landsat 8 and 9 images along with Sentinel images, that illustrate the impact of essentially snowcover free glaciers during the summer of  2022 and 2023 due largely to a January heat wave in 2022 (Washington Post, 2022) and February heat wave in 2023 (Pelto, 2023).

Point A is a small glacier in a south facing cirque below Alto de los Pejerreyes. From 2014 to 2023 area declined from 0.3 km² to 0.1 km². There is remanent glacier ice, but this is no longer active ice and will soon disappear. At Point B in 2014 the area of remanent glacier ice is 0.1 km², by 2023 it is gone. At Point C the glacier has declined from  0.35 km² to 0.15 km² and retreated 300 m from 2014-2023.  At Point D a bedrock area amidst the Maria Angeles Glacier, has expanded from 0.04 km² to 0.20 km², this reflects the lack of flow now reaching the terminus, which retreated 700 m from 2014-2023. At Point E the glacier has retreated 300 m and is separating into three fragments. At Point F the bedrock area amist Palomo Glacier has expanded from 1.1 km² to 1.7 km² between 2016 and 2023. This again reflects diminineshed flow to the terminus which has retreated 800 m during this period, ~100 m/year.  At Point G two glacier tongues connected to the Norte Cipreses Glacier in the valley below in 2014. By 2018 they had nealy separated and by 2023 they had completely separated from the glacier below, retreating 200-300 m to the top of this bedrock step. At Point H, the glacier disconnected from Norte Cipreses Glacier in the valley below after 2002 and retreated 300 m from 2014-2023. There is also a new expanding bedrock area high on the glacier, Point I below. The story is not unique with Sollipulli Glacier to the south and Rio Atuel glaciers in the next watershed to the east also having lost their snowcover in 2022 and 2023.

Retreat of Palomo Glacier from 2016 (red arrow) to 2023 (yellow arrow), 800 m. Separation of tributaries at G, yellow arrows that had fed Norte Cipreses Glacier. False color Sentinel images.

 

Glacier loss at Point B, Glacier retreat at Point C, yellow arrows marks 2016 location. Bedrock expansion at Point D, E and I. retreat from green arrow to yellow arrow of the Maria Angeles Glacier terminating near Point D. Glacier retreat at Point H, yellow arrows marks 2016 location. False color Sentinel images.

Glacier O’Higgins, Chile Rapid Calving Retreat 2016-2023

On By mspeltoIn chile glacier melt, chile glacier retreat

Glacier O’Higgins in February 16, 2023 Sentinel image with the 2002, 2016 and 2019 terminus also indicated. Point D marks a detached lobe on of ice on the northern margin in 2023. Point F marks the southern margin terminus front.

Glacier O’Higgins is a large outlet glacier of the Southern Patagonia Icefield (SPI) that terminates in Lago O’Higgins. Cassasa et al (1997) report that from 1896-1979 the glacier had retreated 13.8 km up an inlet of Lago O’Higgins.  The glacier remained stable in this position from 1979-1986 with a retreat of 800 m from 1986-1995.  Schaefer et al (2015) examined the mass balance of SPI and found Glacier O’Higgins had a calving flux of 2.15-2.97 cubic kilometers/year, and a calving front velocity of 2300 m/year. Malz et al (2018) noted a mean elevation change of -1.04 m/year for Glacier O’Higgins from 2000-2016, with the greatest thinning near the terminus.  Despite this thinning there is limited retreat during this period as the glacier terminated on a shallow bedrock sill (Gorlet et al 2016). They observed that the bed elevation of O’Higgins dropped off into a deeper basin beyond this ~1 km wide sill and remained below sea level for 15-20 km inland of the 2012 ice front location. Here we use 2016-2023 Landsat imagery to update changes observed from 1986-2018.

Topographic map of the terminus area of Glacier O’Higgins, with the ~2016 terminus. Note the elevation step at both the 2016 terminus sill and the sill just upglacier of the 2023 terminus.

From 2002-2016 retreat is limited with the terminus located on a sill, then in 2016 the glacier begins to retreat off of the sill into the deeper sub-glacial basin leading to a rapid retreat from January 2016 to February 2019 of  1900 m on the southern margin, 1800 m in the center and 600 m on the north side, with total recession of 3.0 km². The calving front was 1.75 km widenwith the glacier having retreated into a confined channel. From 2019-2023 the rapid retreat across the sub-glacial basin continued isolating a stagnant region on the north side of the terminus (Point D). The main calving front in 2023 is 1.6 km long with the stagnant region still calving as well. The recession from 2016-2023has been 7 km² with 4 km² from 2019-2023.  The retreat since 2016 has been 3000 m on the northern margin, 3700 m in the center and 3500 m on the souther margin. The glacier along the southern margin in 2023 is near the next bedrock sill as identified by Millan et al (2019).  The sub-glacial basin between sills is ~4-5 km across, helping drive the rapid retreat across the basin. This is evident in the topographic map as well. The northern terminus still is over deep water, and has ~1 km to retreat to reach the sill crest.  Millan et al (2019) Figure 3 illustrates this is a wide sill that should provide short-term terminus stability until further thinning driven by mass balance losses leads to retreat much as occurred from 2000-2016. The retreat of this glacier is similar to that of Dickson Glacier and Upsala Glacier.

Glacier O’Higgins in Jnauary 9, 2016 Sentinel image Point D marks a detached lobe on of ice on the northern margin in 2023. Point F marks the southern margin terminus front in 2023.

Glacier O’Higgins in February 10, 2019 Sentinel image . Point D marks a detached lobe on of ice on the northern margin in 2023. Point F marks the southern margin terminus front in 2023.

Glacier O’Higgins in February 16, 2023 Sentinel image with the 2002, 2016 and 2019 terminus also indicated. Point D marks a detached lobe on of ice on the northern margin in 2023. Point F marks the southern margin terminus front. LM marks the lateral moraine from the Little Ice Age. FF is the forefield that has been deglaciated for ~50 years.

Sollipulli Glacier, Chile Rapid Melt: Fire and Ice February 2023

On By mspeltoIn chile glacier melt, chile glacier retreat2 Comments

Sollipulli Glacier, Chile snowcover loss during summer 2023 heat wave in false color Sentinel images from January 20-Feb. 9. Snowcover delcined from 94% to 12% in 20 days.

Nevados de Sollipulli is a volcano, is in the central Andes of Chile near the border with Argentina in Parque Nacional Villarica, Chile. The 4 km wide summit caldera at ~2100 m is filled by a glacier.  In 2022 the summer heat waves stripped the glacier of all snowpack in January and that persisted through March, see below (Pelto, 2022). The volcano is dormant last producing lava flows 700 years ago and last erupting 2900 years ago (NASA, 2017). Reinthaler et al (2019) identified a 27% decline in glacier area from 1986-2015 on 59 volcanoes in the Andes. The study included Sollipulli where the area declined from 16.2 km2 in 1986, 20 12.5 km2 in 1999 and 11.1 km2 in 2015 (Reinthaler et al 2019). Here we examine Landsat imagery illustrating the recession from 1986-2022 and the loss of all snowcover for most of the summer of 2022. The summer of 2022 led to early summer loss of most/all the snowpack on Central Andes glaciers from 30-40 S. (Pelto, 2022).

This summer central Chile has experienced a persistent extreme heat wave that has generated ongoing disastrous forest fires (NASA EO, 2023), CONAF continues to update the fire area daily. Most of the Solllipulli Glacier is at  2000-2200 m elevation, CECS has a weather station at 1900 m on nearby Volcan Villarrica that had a high temperature on Jan. 29 and Feb. 4 of  over 24 C. The highe tempertature has been above 16 C everday from Jan. 28 to Feb. 8 (see below). This has led to the snowcover diminishing rapidly on Sollipulli Glacier from January 20 to February 9, 2023. The glacier was 94% snowcovered on Jan. 20, 84% on January 30, 35% on Feb. 4 and 12% on Feb. 9. How long until it is down to 0%? This blog will be updated in this coming week to identify that and to better quantify the heat. By February 17, 2023 snowcover is down to 1%

Sollipulli Glacier, Jan. 20, 2022 and fifty five days later the glacier is still bare of snowpack.

Sollipulli Glacier on Feb. 17, 2023 in false color Sentinel image, 1% snowcover left.

Temperature from the CECS station on Volcan Villarica at 1900 m. showing the average minimum and maximum.

 

Sollipulli Volcano Glacier Recession Snow Cover Deficit

On By mspeltoIn chile glacier melt, chile glacier retreat

Landsat images of Sollipulli from 1986 and 2022. Point A-D are locations where the glacier spilled out of the caldera in 1986, but no longer does so in 2022.

Nevados de Sollipulli is a volcano, is in the central Andes of Chile near the border with Argentina in Parque Nacional Villarica, Chile. The 4 km wide summit caldera at ~2100 m is filled by a glacier. The volcano is dormant last producing lava flows 700 years ago and last erupting 2900 years ago (NASA, 2017). Reinthaler et al (2019) identified a 27% decline in glacier area from 1986-2015 on 59 volcanoes in the Andes. The study included Sollipulli where the area declined from 16.2 km2 in 1986, 20 12.5 km2 in 1999 and 11.1 km2 in 2015 (Reinthaler et al 2019). Here we examine Landsat imagery illustrating the recession from 1986-2022 and the loss of all snowcover for most of the summer of 2022. The summer of 2022 led to early summer loss of most/all the snowpack on Central Andes glaciers from 30-40 S. (Pelto, 2022)

In 1986 a Landsat 5 image illustrates that the glacier not only fills but overflows the caldera at Points A-D, with Point A and B feeding significant glacier area. The glacier is also almost completely snowcovered in late February. In 2003 the glacier is still spilling over at Point A, and is almost entirely snowcovered in mid-February. On January 8, 2022 the glacier is already 95% free of snowcover with some snow patches on the NW margin. By January 24 the glacier is 99% snow free and remains snow free through mid-March in a Landsat and Sentinel image from 3-13 and 3-16 respectively. There is a small patch of relict glacier ice near Point B, while the former glacier at Point A has disappeared. The annual layering preserved in the glacier ice as seen in the Landsat Band 5 image will continue to evolve as the glacier thins.  The dirty nature of this ice enhances solar radiation melting, particularly compared to snowcover.  Two months of exposure at the 2100 m elevation ice cap will have led to several meters of ice loss. The extent of the glacier has declined to 10.2 km2 in March 2022 a 37% decline since 1986.

Landsat images indicating the near complete snowcover in Landsat 7 image from 2003 and the loss of all snowcover that continued from January until at least March 13 2022. Note the annual layers preserved in the glacier ice now exposed at the surface.

Sollipulli Glacier in early January with only a fringing area of snowpack along the northwest margin. Sixty-four days later the glacier is still bare of snowpack.

Hornopirén Glaciers, Chile continue a Spectacular Retreat 1985-2022

On By mspeltoIn chile glacier retreat

Rio Blanco Glaciers in Hornopirén Naitonal Park, Chile in Landsat 5 and 9 images from 1985 and 2022. Red arrows indicate 1985 terminus position, yellow arrows 2022 terminus position. Point A is an emerging bedrock nunatak and Point B is where tributary separation has occurred.

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 km2 in 1986 and 96  km2 in 2011.  The retreat of the largest glaciers in the park is spectacular in recent years.Barcaza et al (2017) indicate that Inexplorado glaciers have lost 0.46-0,48 km2 from 2003-2015. Here we examine Landsat imagery to identify changes in three of the larger valley glaciers from 1985-2022.  These glaciers from the headwaters of the Rio Blanco and are designated Inexplorado (RB), Rio Blanco North (RBN), Rio Blanco South (RBS).  Rio Blanco enters the ocean just east of the community of Hornopirén.

In 1985 the 8 km long RBN and RBS glaciers merged just above the terminus at 820 m, red arrow. In 1985 Inexplorado  (RB) was a 7.5 km long glacier terminating at The snowline was at 1300 m.  By 2001 RBN and RBS had separated by ~1 km with the formation of a new lake at the former terminus. RBS is developing a nunatak at Point A. Inexplorado had retreated 1 km with a proglacial lake just beginning to develop at the terminus, while the northern tributary at Point B is still feeding the main glacier. By 2016 the retreat of RBN has led to the development of  three new alpine lakes in the deglaciated valley.  By 2016 RBS thinning and retreat has led to the Point A nunatak in the lower section of RBS becoming a significant bedrock exposure.  In 2016 The retreat of Inexplorado has led to the formation of a nearly 0.9 km long proglacial lake and the former northern tributary at Point B has separated.  By 2022 RBN has retreated 4.8 km losing 60% of its length since 1985, it has detached from the accumulation and the eastern margin has two lobes now terminating in proglacaial lakes.  RBS has retreated 4 km, losing 45% of its length since 1985. Point A is beginning to merge with terminus and the main terminus is likely retreating into a new lake basin. Both RBS and RBN terminate at ~1200 m. Inexplorado has retreated 2.3 km since 1985, 30% of its length, and is still 5.3 km long, terminating at ~1300 m,  A new lake basin will likely form between the current terminus and the base of the cefall 1.5 km upglacier of the terminus. The snowline in 2015, 2016 and 2022 was 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 ~50% of their length and 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 or to the south at the Quelat Glacier Complex.

Rio Blanco Glaciers in Hornopirén Naitonal Park, Chile in Landsat 7 and 8 images from 2001 and 2016. Red arrows indicate 1985 terminus position, yellow arrows 2022 terminus position. Point A is an emerging bedrock nunatak and Point B is where tributary separation has occurred.

The Rio Blanco North Glacier in March 2022 Sentinel image indicating the two proglacial lakes on eastern margin, purple arrows, the detachment at the green arrow, 1985 terminus locaiton red arrow and 2022 terminus location yellow arrow.

Palomo Glacier, Chile Snow Cover Loss in 2022 and Accelerating Retreat

On By mspeltoIn chile glacier melt, chile glacier retreat, Chile glaciers and hydropower

Palomo Glacier, Chile in Landsat 5, 8 and 9 images illustrating retreat from 1987 position, red arrow, and expansion of bare rock areas amidst the glacier at Point A,B and C. Note lack of retained snowcover in 2022.

Palomo Glacier is a large valley glacier in Central Andes of Chile. Adjacent to the Cortaderal Glacier and Universidad Glacier, it flows east from Volcan Paloma (4860 m)  and drains into the Rio Cortaderal. Rio Cortaderal is in the Cachapoal River watershed that supplies two Pacific Hydro projects; a 110 MW run of river project at Chacayes and the 78 MW Coya run of river project a short distance downstream. The glacier is an important water resource from December-March. Bravo et al (2017) quantified this resource for nearby Universidad Glacier that supplied 10-13% of all runoff to the Tinguirica Basin during the melt season. La Quesne et al (2009) reported that Palomo Glacier retreated 1160 m from 1955-1978 and advaned ~50 m from 450 m 1987-2007. They reported that Palomo Glacier had an equilibrium balance durng the 1987-2000 period, which drove the lack of retreat. Here we examine the changes of this glacier from 1987-2022 using Landsat 5, 7, 8 and 9 images, and the unusually high snow lines during the winter of  2022 due largely to a January heat wave (Washington Post, 2022). This is the first post using Landsat 9, that extends this invaluable data record.

 

In 1987 Palomo Glacier terminus had been in slight advance over the previous decade. The area of bare rock at Point A was 0.25 km2. At Point B and C limited exposed rock was evident on two rock ribs.  The snowline is below Point A at 3300 m. By 2002 there is minor retreat and the area of exposed rock at Point A has expanded, with the snowline at 3600 m. By 2015 the terminus has retreated 700 m to the north end of steep slope on the east margin of the glacier. The exposed bedrock area at Point A is now 1 km2. the snowline is at 3800 m.  By mid-January 2022 the glacier has only ~10% snowcover remaining, mostly above 4000 m. Retreat since 1987 is now ~1200 m. The bedrock area at Point A is 1.5 km2. Point B is expanding ridge of bedrock and the rib or rock at Point C now separates the glacier from flow on the south facing slope east of Point C.

By February 8, 2022 with six weeks left in the melt season there is no evident retained snowpack. This will accelerate both retreat, thinning and area loss of this glacier.  This story is playing out at glaciers across the region such at Olivares Glacier, Chile,  Cortaderal Glacier, Chile and Volcan Overo, Argentina

Palomo Glacier, Chile in Landsat 7 and 9 images illustrating retreat from 1987 position, red arrow, and expansion of bare rock areas amidst the glacier at Point A,B and C.

Olivares Beta and Gamma Glaciers, Chile Bare of Snowcover in 2022

On By mspeltoIn chile glacier melt, chile glacier retreat, Chile glaciers and hydropower

Olivares Beta (B) and Olivares Gamma (G) Glacier in Sentinel image from 1-23-2022, illustrating the lack of retained snowcover with 8 weeks left in the melt season. The yellow arrow marks proglacial lakes below each glacier. The red arrow an area of emerging bedrock on the upper Beta, X marks a location where the glaciers were joined in 1986 and now have separated. 

Olivares Beta and Olivares Gamma Glacier are adjacent glaciers 50 km NE of Santiago Chile in the central Andes of Chile. The glaciers are at the headwaters of the Olivares River, which drains into the Coloardo River. The Alfalfal Hydropower Planton the Colorado River is a 178 MW run of river plant completed in 1991 and owned by AES Andes. Malmros et al (2016) identified the retreat and area change of te Olivares glaciers for the 1955-2013 period. They noted a retreat of 979 m from 1955-1994 on Olivares Beta and 753 m on Olivares Gamma Glacier. The identified area loss from 1955-2013 was 21% on Olivares Beta and 34% Olivares Gamma.  Dussaillant et al (2019) identified a slower mass loss  -0.28 m/year in this region from 2000-2018, than further south in the Patagonia Andes or north in the Tropical Andes. Here we examine Landsat imagery from 1986-2020 and Sentinel Imagery from 2020-2022 to identify changes in area and snowcover.  The lack of retained snowcover indicates mass balance losses which will drive further retreat.

Olivares Beta (B) and Olivares Gamma (G) Glacier in Landsat images from 1986, 1993, 2015 and 2020. The yellow arrow marks the terminus location in 1993 of both glaciers, the red arrow an area of emerging bedrock on the upper Beta, X marks a location where the glaciers were joined in 1986 and now have separated. 

In  1986 and 1993 both glaciers terminated in small proglacial lakes, yellow arrows, and were connected adjacent to Point X.  There is no evident bedrock emerging on the upper Beta. In 1986 there is limited retained snowcover, ~10% of total area by early March. In 1993 there is 30% snowcover on the glaciers in March. By 2015 the glacier had receded from the proglacial lakes, bedrock is emerging at the red arrow on the upper Beta, and the glaciers are barely connected at Point X. Snowcover is ~10% of total area in mid-February.  In 2020 the glaciers have disconnected at Point X and there is less than ~10% retained snowcover by mid-February. The proglacial lakes are also quite brown suggesting high runoff from the dirtier/darker glacier. By January 23, 2022 both glaciers have again lost almost all snowcover with 8 weeks left in the melt season. The dirtier firn and ice at the surface melts at a faster rate than snow for the same weather conditions.  The result will be large mass balance losses in 2022 that will further lead to glacier thinning and recession. Both glaciers currently extend from ~3800 m to ~4800 m, with areas below 4600 m consistently being in the ablation zone.

The early loss of snowcover has been seen on other nearby glaciers Cortaderal Glacier, Chile and Volcan Overo, Argentina due to the unsually warm conditions in the region, particularly in the first half of January.

Olivares Beta (B) and Olivares Gamma (G) Glacier in Sentinel image from 2-18-2020 illustrating the lack of retained snowcover with 4 weeks left in the melt season. The yellow arrow marks proglacial lakes below each glacier. The red arrow an area of emerging bedrock on the upper Beta, X marks a location where the glaciers were joined in 1986 and now have separated. 

Olivares Beta and Olivares Gamm

 

Cortaderal Glacier, Chile 2022 Heat Wave Reduces Snow Cover, Retreat Continues

On By mspeltoIn chile glacier melt, chile glacier retreat, Chile glaciers and hydropower3 Comments

Cortaderal Glacier in Landsat images from 2014 and 2022. The glacier retreated 1400 m during this interval. The snowline in January 2014 is at 3750 m. On January 15, 2022 the snowline averages 4100 m with less than 15% snowcovered with 2.5 months left in the melt season. Red arrow is 2014 terminus and yellow arrow is 2022 terminus.

Cortaderal Glacier is a large valley glacier in Central Andes of Chile. Adjacent to the Universidad Glacier, it flows from Volcan Paloma (4860 m) and Nevado Penitente (4350 m) and drains into the Rio Cortaderal. Rio Cortaderal joins the Cachapoal River, that supplies two Pacific Hydro projects; a 110 MW run of river project at Chacayes and the 78 MW Coya run of river project a short distance downstream. The glacier is an important water resource from December-March. Bravo et al (2017) noted for Universidad Glacier that it supplied 10-13% of all runoff to the Tinguirica Basin during the melt season. La Quesne et al (2009) reported that Cortaderal Glacier retreated 110 m from 1970-2000 and 450 m from 2000-2007. Here we examine the retreat of this glacier from 2014-2022 and the unusually high snow lines in mid-January of 2022 due to the recent January heat wave (Washington Post, 2022).

Cortaderal Glacier in Sentinel images from 2016 and 2022. Point A is the bedrock area that emerged in 2016 and was at the glacier front by 2022. Point T marks the 2016 terminus position, Point B is at 3750 m and Point C is at 4200 m. Snowline on January 22, 2016 is at 3200 m and averages 4100 m on January 13, 2022.

In February of 2014 the glacier terminated on the outwash plain at 2800 m. The snowline in mid January was at 3750 m. On January 9, 2016 the snowline was at 3200 m.  At Point A a small bedrock area has emerged from beneath the ice  1 km upglacier of the terminus. On January 16, 2017 the snowline is at 3750 m. On January 19, 2019 the snowline is at 3700 m. The bedrock exposed at Point A is no longer surrounded by ice due to expansion and glacier retreat. On December 14th the snowline is at 3700 m and the glacier is 50% snowcovered. By January 15 there is less than 15 % snowcover, and the snowline averages 4100 m, nearly at the top of the glacier. With 10 weeks left in the melt season snowcover will decline further. This is reminiscent of reduced snowcover on glaciers in the Pacific Northwest due to the summer 2021 heat wave (Pelto, 2021).

The glacier has retreated to Point A, with an average frontal recession of 1300 m from 2014-2022. This is greater than the retreat from 1990-2014 of ~800-900 m (Pelto, 2014).  The glacier now terminates at 3050 m in a region of much steeper slope that will reduce the retreat rate in the near future.

Cortaderal Glacier snow covered area change in two Landsat images one month apart. Snowcover declined from ~50% to 15%.

Cortaderal Glacier in Sentinel images from 2017 and 2019. Point A is the bedrock area that emerged in 2016 and was at the glacier front by 2022. Point T marks the 2016 terminus position, Point B is at 3750 m and Point C is at 4200 m. Snowline on January 16, 2017 is at 3750 m and averages 3700 m on January 19, 2019.

Landsat image indicating retreat from 1990-2014 of Cortaderal Glacier, red arrow 1990 position, yellow arrow 2014 position.