Category: climate change glacier retreat

Team Perspectives from 2026 North Cascade Glacier Climate Projects Field Season

On By mspeltoIn climate change glacier retreat, glacier climate change, Glacier Observations, North Cascade GlaciersLeave a comment

Jill Pelto: Field painting of new large bedrock exposures in the big icefall on Easton Glacier, Mt. Baker. The 2026 field season of the NCGCP brought dramatic changes. While we expected most of these, it doesn’t make them any easier to physically navigate or emotionally experience. Even at 9,000 ft, the glaciers of Mt. Baker are thinning, with new bedrock emerging. Above about 7,000 ft, the snowpack was decent, which will slightly help to mitigate the losses from lack of snowpack at lower elevations. The atmospheric river carved a story across our field sites. From this big shift in snowpack up high, to washed out roads, and altered riverbeds. It was a year of fascinating, sad, and occasionally hopeful shifts.

Abby Connor: Looking down at the terminus of the Lower Curtis Glacier on Mt. Shuksan, noticeably thinner than when I last visited. I grew up in Bothell, in a family that spends its weekends outdoors, assuming that massive and seemingly unchanging glaciers are a fact of life. But as we approached our first field site on the Lower Curtis Glacier on Mt. Shuksan, I struggled to reconcile the view of the noticeably less massive terminus of the glacier with my memory from my last visit eight years ago. When we reached our break spot and looked far down at the glacier, Mauri described the wall that would have towered 100 feet over where we sat, before the glacier had lost its impressive thickness. Throughout the 2026 field season, I was continually awed with the scale of the glaciers we still have in the North Cascades while surrounded by reminders of how quickly they’re disappearing, fast enough that we are on track to lose almost all of our glaciers in the state within my lifetime. In Western Washington, a place defined by the mountains and Sound, glaciers are the link between the two. They are no longer an unchanging fact of life.

Ava Reynolds: Pink monkey flower and fireweed bloom in the rocky moraine of the Columbia Glacier – one of the glaciers in the 2026 field season that looked the most impacted by warm temperatures and a reduced snowpack, with avalanche bands that feed the glacier now shutoff, rockfall evident across the entire glacier, and a growing lake of floating ice at the terminus.This field season was visually striking, highlighting the impact of our warming climate on the glaciers and surrounding ecosystem. Flowers were blooming weeks ahead of schedule, sections of new bedrock were exposed, wildfires dotted the horizon at every field site, and residual evidence from the December 2025 storm system was prevalent in downed trees and washed out riverbeds. 

Shaina Dotson: Amidst the icefall of Easton Glacier. Joining the NCGCP this field season was equal parts breathtaking and sobering. Each glacier was stunning and wholly its own — ancient and irreplaceable — yet we were immersed in the evidence of a warming planet. Wildfire plumes lined the horizon, ice thinned and retreated where it once held firm, and every day I found myself torn between the beauty of this world and its unraveling.

Danielle Schlunegger-Warner: Red Lens over Rainbow Glacier with Ice Alge sampled from Rainbow Glacier in the microscope. As an artist invited out to attend the 43rd field season with NCCGP, I spent my time in immersed with looking and observing. My attention drew not just to the fantastical forms of the ice on the glaciers, but the way they change the landscape around them. I saw ice algae and tiny black worms dotting the ice and snow, listened to the life bubbling up in the streams at their edges.The focus shifted between the expansive ancient glaciers, microorganisms, and the yearly changes diligently measured by the NCCGP with somber results. This experience illuminated for me not just that these glaciers the heartbeat of the North Cascades, but that their impact ripples out into our own lives in ways that are worth paying more attention to.—I had a tough time picking an image! If possible I’d love to share either the large lens picture or the Alge and red lens together. Send along what makes the most sense! 

Rikki Held: Rainbow Glacier cave with Mauri for scale. The 43rd field season of the NCGCP was filled with both devastating and beautiful moments. We traversed landscapes with fresh glacier-fed streams, rugged mountains, wildflowers, mountain goats, and glaciers with unique formations and characteristics, while also witnessing heartbreaking sites including the large cave hollowing out Rainbow Glacier’s terminus on Mt. Baker and wildfire smoke plumes throughout the field season. Mauri and Jill shared their multi-year observations noting vegetation changes, newly exposed bedrock, and how far the glaciers have receded since they first visited them – e.g., Easton Glacier has retreated around 750m since 1990. This project highlights the importance of long-term data collection, science communication, and personal narratives as we all work to reduce the impacts of anthropogenic climate change and protect the environmental systems we depend on.

Mauri Pelto: Rainbow Glacier cave at the terminus with Abby and Rikki in foreground, viewed from an area where a previous cave had collapsed. Large ice caves are features of retreating glaciers where warm air circulates expanding the cave until it collapses. We observed several of these at the terminus of glaciers on Mount Baker this summer. The largest was at the terminus of Rainbow Glacier. The cave is large enough to hold a cape style house. It will collapse by the end of summer driving further retreat. The size of this cave and the roar of the water was quite intimidating.

Petermann Glacier, NW Greenland Releases Massive Iceberg in August 2026.

On By mspeltoIn climate change glacier retreat, Greenland glacier retreat1 Comment
Petermann Glacier in Landsat images from July 21st and Aug. 13 2026. Indicating the rift that leads to iceberg calving of berg A-yellow arrows. Additional significant rifting inidicated by red arrows. Berg B is not a stable configuration.

The Petermann Glacier in northwest Greenland is significantly different than the fast flowing large outlet glaciers, such as the Jakobshavn and Helheim Glacier we here so much about. Petermann Glacier is much thinner at the calving front and moves much slower. The volume flux from this glacier is much less than Jakobshavn which loses 40 km3 per year, versus 1 km3 at the calving front of Peteramann and 12 km3 at the grounding line. A detailed review of some of the differences is explored in an article I wrote for Realclimate in 2008. In 2008 Petermann Glacier lost a substantial area, 29 km2 due to calving. Additional large calving events in 2010, when a 250 km2 berg broke off and in 2012 a 32 km2 berg broke off (NASA, 2023).

This summer the rifts that have been evident for some time cutting across the glacier led to a calving event on Aug. 4th, reported by Univesity of Ottawa researcher Adam Garbo. Because of the flat nature of this feature it can be referred to as an ice island as well. Imagery from July 21 indicates no calving. By August 6th berg A, with an area of 75km2 . The glacier thickness at the calving front is less than 150 m, which allows this berg to cross the sill that is 350-450 m deep (Tinto et al 2015), and move out of the fjord. The berg has moved 28 km from Aug. 4 to Aug. 13, a velocity of ~3 km per day. Becuase the ratio of berg length and width to thickness, this is not an iceberg that will turnover. Exiting the fjord the iceberg has turned southwest.

Existing rifting indicates that additional iceberg B will break off in the near future, behind this additional rifting indicates a weakness cutting across almost the entire glacier for additional calving that will occur in the next several years, though likely not as a single large ice berg. This is the largest observed calved ice berg in the Northern Hemisphere in 2026.

Petermann Glacier in Landsat images from Aug. 6th and Aug. 13 2026. The iceberg has separated by just a 5 kilometers by Aug. 6th, and 28 km by Aug. 13th. Additional significant rifting inidicated by red arrows. Berg B is not a stable configuration.

Global Alpine Glacier 2025 State of Climate Report

On By mspeltoIn climate change glacier retreat, glacier climate change, Glacier ObservationsLeave a comment
Figure 1. Global mean annual balance (bars) and cumulative balance (line) from the WGMS data set.

Each year since 2008 I have been responsible for summarizing the global alpine glacier status for each specific year in the Bulletin of the American Meteorological Society State of the Climate report. The 2025 report came out in early August. Below is the report with several added figures.

The 2025 World Glacier Monitoring Service (WGMS) dataset of annual glaciological mass balance observations includes 162 glaciers from six continents and 26 nations, 158 with a negative balance and four with a positive balance. In 2025, the mean annual mass balance of the 59 reporting global reference glaciers was –1.34 m w.e., and -1.34 m w.e. for all 162 reporting glaciers. The 2025 regionalized global average annual balance of –1.09 m w.e., is the fourth consecutive year with mass balance loss exceeding 1.0 m w.e., 2023 had the most negative -1.23 m w.e and 2024 was at 1.04 m w.e. Since 1976, mountain glaciers and ice caps have lost 9179+621 Gt of water, contributing 25.3+1.7 mm to the global mean sea level rise, with 41% of this loss occurring in the last decade (Dussaillant et al. 2025).

The mean annual balance of global reference glaciers was -1.34 m w.e., a similar result to 2023 and 2024 with a mean annual balance for global reference glaciers of -1.60 m w.e. and -1.37 m w.e., respectively.  This makes 2025 the 38th consecutive year with a global alpine mass balance loss, the 16th consecutive year with a regionalized global mass balance below –0.5 m w.e. The significant acceleration of mass balance loss is evident in glaciological observations, geodetic observations, altimetry observations and gravimetric observations (The GlaMBIE Team, 2025). The acceleration of mass balance loss indicates glaciers are not approaching equilibrium and increasingly are disappearing. The Global Land Ice Measurement from Space inventory of global glaciers has now added an extinct glacier layer to record glaciers that have disappeared, that is populated by 181 glaciers that had existed in a previous inventory (Raup et al. 2025). In conjunction with 2025 being the UN International Year for Glaciers’ Preservation the Global Glacier Casualty List has been created to chronicle the story of specific glaciers being lost from each glaciated region (Boyer and Howe, 2025).

Hofsjokull eystri, Iceland was snow free by mid-August, leading to extensive ice cap thinning.

In the European Alps all 54 glaciers observed had negative balances, with 45 of the glaciers losing over 1 .0 m w.e. In Iceland (6) and Svalbard (9) all 15 glaciers observed lost over 1.0 m w.e. In Norway 8 of 10 glaciers had a negative balance, with two glaciers having a positive balance. In Sweden 3 of 4 glaciers had a negative balance.

High snow line on Durung Drung Glacier, India near end of summer monsoon season.

In Asia all 23 glaciers across 7 nations had negative balances averaging 0.97 m w.e. In New Zealand the glaciers observed had a negative mass balance.

Agua Negra Glacier, Argentina with minimal snow cover at end of summer melt season.

In the Andes Mountains of South America nine of ten, reporting from four nations, had negative balances, with an average balance of -0.92 m w.e.

All 14 glaciers in Western North America, outside of Alaska, had mass balance below -1.0 m w.e. with an average of -2.24 m w.e. Peyto Glacier, Canada exemplifies the limited retained snow cover on alpine glaciers in Western North America in 2025, a glacier should be 50-60% snow covered at the end of summer to be in equilibrium (Fig X2). It is evident Peyto Glacier is representative of adjacent glaciers that also have limited retained snow cover.  In Alaska 3 of 4 glaciers had negative balances. The five glaciers in Arctic Canada all had small negative balances averaging -0.16 m w.e.

Snow cover was minimal in the Yoho-Peyto Glacier regions, Canada at the end of the melt season.

Alpine annual mass balance glaciological observations are reported to the WGMS by National representatives with a December 1 annual submission deadline. WGMS reference glaciers (60) have at least thirty continuous years of mass balance observation. Benchmark glaciers (23) have at least a ten-year mass balance record and are in regions that lack sufficient reference glaciers. The combination of benchmark and reference glaciers are used to generate regional averages (WGMS, 2023). Global values are calculated using a single averaged value for each of 19 mountain regions, limiting bias from observed regions (WGMS, 2023). Expansion of this data set leads to reanalysis and updated values.

References

Boyer, D. and Howe, C. 2025. Communication efforts to educate the public about vanishing glaciers, 1958–2025. Annals of Glaciology, 67: e2. doi:10.1017/aog.2025.10033

Dussaillant, I., Hugonnet, R., Huss, M., Berthier, E., Bannwart, J., Paul, F., and Zemp, M. 2025: Annual mass change of the world’s glaciers from 1976 to 2024 by temporal downscaling of satellite data with in-situ observations. Earth System Science Data 17(5): 1977-2006, https://essd.copernicus.org/articles/17/1977/2025/.

Raup, B., Andreassen, L., Boyer, D., Howe, C., Pelto, M., and Rabatel, A. 2025: Tracking extinct glaciers in GLIMS. Annals of Glaciology, 66, e35, 1–6. https://doi.org/10.1017/aog.2025.10027

The GlaMBIE Team, 2025: Community estimate of global glacier mass changes from 2000 to 2023. Nature. https://doi.org/10.1038/s41586-024-08545-z.

WGMS 2023: Global Glacier Change Bulletin No. 5 (2020–2021). Zemp, M., Gärtner-Roer, I., Nussbaumer, S.U., Welty, E.Z., Dussaillant, I., and Bannwart, J. (eds.), ISC(WDS)/IUGG(IACS)/UNEP/UNESCO/WMO, World Glacier Monitoring Service, Zurich, Switzerland, 134 pp., publication based on database version: doi:10.5904/wgms-fog-2023-09. [NG5] [MP6] 

Datasets used and their URLs

Dussaillant, I., Hugonnet, R., Huss, M., Berthier, E., Bannwart, J., Paul, F., and Zemp, M. (2025): Annual mass-change estimates for the world’s glaciers. Individual glacier time series and gridded data products. Digital media. https://doi.org/10.5904/wgms-amce-2025-02b[NG7] [MP8] 

Barnes Ice Cap and Baffin Island Glaciers Lose Snow Cover in July 2026

On By mspeltoIn Canada glacier retreat, climate change glacier retreatLeave a comment
Barnes Ice Cap having in Landsat image with well developed melt channels from crest to margin of ice cap. Snow cover has been lost with over a month left in melt season.

Barnes Ice Cap located in the center of Baffin Island, Canada covers an area of ~5731 km2 in 2021 (Rippin et al 2026). The ice cap is approximately 150 km long, 60 km wide and has maximum ice thickness of ~730 m and a maximum ice elevation of 1124 m above sea level (asl) at the summit of the north dome. ICESat altimeter data indicated the thinning of the BIC at a mean rate of 0.75 m/year for the 2003–2009 period Gilbert et al (2016). They also noted that the ELA was at 950 in the 1960-80 period and is at 1100 m from 2002-2010 this leaves  a limited accumulation zone area. observe that  Barnes  Ice Cap lost its accumulation area beginning in 2010, in part due to the longer melt season.  The glacier does tend to not retain snowcover the accumulation zone consists of superimposed ice at the crest. Papasodoro et al (2016) noted that glacier wide balances were −0.52  m w.e./year from 1960 to 2013 and doubled to −1.06m w.e./year from 2005 to 2013 and remained at ~-1 m/a year through 2021 (Rippin et al 2026).

This has enabled supraglacial channels/valleys to develop and expand from year to year, extending from the ice cap crest to the margin, providing an effective pathway for meltwater to leave the ice sheet (Rippin et al 2026). This greatly diminishes refreezing, which had been the key mechanism for accumulation. The channels persist through and between melt seasons. There is insufficient ice motion or annual accumulation to offset the melt season runoff impact. Note the Band 4 image below indicates the extent of specific channels and how they cross cut specific stratigraphic ice horizons (H). Winter conditions were 3-5 C above average in the area, with spring and early summer conditions being normal or slightly below normal. This combined with the rapid snow loss on the ice cap between June 24 and July 12 indicates that snowpack was thin.

Barnes Ice Cap southern lobe with specific supraglacial stream channels noted. These have incised into the surface and persist. They cross stratigraphic ice horizons (H) near the margin of this Landsat Band 4 image from July 12, 2026.
Winter temperature anomaly across the Arctic.
Glaciers on Peninsula on northern side of Home Bay having lost nearly all snowcover by July 15, 2026 in this Landsat image.

In mid-July 2026 Landsat imagery indicates the loss of all snow cover on Barnes Ice cap and that the supraglacial streams are fully activated. A series of glaciers to the east of the ice cap also have lost all snowcover including Keyhole, Kitarchick and Nuusuq Glacier. With over a month left in the melt season this will lead to substantial mass balance loss of these glaciers, driving further thinning and recession. Decade Icefield just to the north of this trio of glaciers also has lost all snow cover by mid-July.

Decade Icefield in Landsat image from mid-July has lost its snow cover.
Barnes Ice Cap southeast region illustrating suprglacial stream extent and lack of snowcver from margin to summit of ice cap in Landsat image.

Miles Glacier, Alaska Retreat-Van Cleve Lake Outburst 2026

On By mspeltoIn alaska glacier retreat, climate change glacier retreat, glacier climate change2 Comments
Miles Glacier and Van Cleve glacier lake (VC) near its maximum size on June 19th and after drainage on July 9th in Sentinel images. Glacier margin black dots.

Miles Glacier terminates in an embayment on the east side of the Copper River, Alaska. A secondary terminus on the north side of the main glacier has long impounded a glacial lake that periodically drains. As miles has retreated over the last 40 years the maximum size of the glacial dammed lake has diminished, prior to its drainage. In 1987 the glacier extended onto an outwash plain directly adjacent to the Copper River, the lake reached a maximum size of 12 km2 . From 2016 to 2019 the lake drained each summer reaching a maximum average size of 5.5 km2 (Rick et al 2023). This was noted as a shrinking ice dammed lake by Field et al (2021).

Miles Glacier and Van Cleve glacial lake filling in June 2026 in Landsat images. Glacier margin black dots.

By 2021 the glacier had retreated 3.5 km since 1987. From 2021-2026 the lake reaches a maximum size of 3.5 to 4.0 km2 before draining. On June 2, 2026 the lake still has some winter lake ice and is filling. By June 10th the lake had reached 3 km2 and by June 19th it had reached 4 km2. The lake had began draining before June 25th. By July 9th it was fully drained. The Miles Glacier terminus has retreated 4.5 km since 1987. This ongoing retreat will continue to diminish the size of the lake. Ths lake does not have the complex drainage system or changing drainage location that Berg Lake has with retreat of Stellar Glacier..

Miles Glacier and Van Cleve glacial lake in 1987 Landsat image. Black dots indicate glacier margin.

Miles Glacier and Van Cleve glacial lake in 2021 Landsat image. Black dots indicate glacier margin and yellow arrow indicates 1987 margin.

Hovgard Kystland Glacier Rapid Retreat, West Greenland

On By mspeltoIn climate change glacier retreat, glacier climate change, Glacier Observations, Greenland glacier retreatLeave a comment
Hovgard Kystland Glacier in Sentinel image from July 4, 2026 with margin indicated by black dots. The 2020 margin seen below is indicated by green dots.

Hovgard Kystland Glacier is an outlet glacier in West Greenland between Alison and Hayes Glacier. Alison Glacier had the highest retreat rate from 1976-2021 losing 14.3 km in length and 59.4 km2 in terminus area (Black and Joughin, 2026). Hayes Glacier lost 2.7 km in length and 10.8 km2 in area (Black and Joughin, 2026).. They indicate that Hovgard Kystland Glacier retreated 5.4 km and lost 21.3 km2 during this interval.

Here we examine the acceleration of retreat from 2020 to 2026. In 2020 the central tongue of the glacier extended west beyond the main front. This central tongue collapsed by July 2024 leaving a generally north/south calving front, the glacier had lost 5.7 km2 of terminus area. From July 2024 to July 2026 an embayment formed generating a concave calving front. The glacier terminus lost another 4.8 km of area. Retreat of the calving front was 2.5 km during the 2021-2026 period. The glacier has lost an area that is 50% of the area lost from 1976-2021, in the last five years. The embayment is poised to further expand, though this summer an extensive packed melange is currently in place which typically limits calving (Meng et al. 2025).

Hovgard Kystland Glacier in Sentinel image from July 27, 2020. The 2020 margin seen below is indicated by green dots and the 2026 margin with black dots.

Hovgard Kystland Glacier in July 4, 2024 Sentinel image. The calving front indicated by red dots for 2024 and black dots for 2026.

Alpine Glaciers-State of Climate 2024

On By mspeltoIn climate change glacier retreat, glacier climate change
Global alpine mass balance in 2024 as reported to the World Glacier Monitoring Service. Solid line is the cumulative balance, bars are the annual balance.

Each of the last 15 years I have summarized the annual mass balance of alpine glaciers globally for the Bulletin American Meterological Society-State of the Climate report,. Below is the 2024 section on alpine glaciers with a few added figures.

  • ALPINE GLACIERS
  • M. Pelto

In 2024, all 58 global reference glaciers reported a negative annual mass balance. This is only the second year in the 1970–2024 period with all negative annual balances, following 2023. The global average annual mass balance based on equal weighting of 19 regions is −1.30 m water equivalent (w.e.), the most negative value in the record

The 2024 dataset of submitted glaciological observations includes 142 glaciers from six continents and 27 nations, with 140 reporting a negative balance and 2 a positive balance. In 2024, the mean annual mass balance of the 58 global reference glaciers was −1.44 m w.e. and −1.36 m w.e. for all 142 reporting glaciers. This is a similar result to 2023, which saw a mean reference glacier balance of −1.62 m w.e. and −1.35 m w.e. for all 116 reporting glaciers.

The 2024 regionalized global average of −1.30 m w.e. exceeds the previous most negative year in 2023, which saw a regional-ized global average of −1.25 m w.e. This makes 2024 the 37th consecutive year with a global alpine mass balance loss and the 15th con-secutive year with a regionalized global mass balance below −0.5 m w.e. The acceleration of mass balance loss indicates that alpine glaciers are not approaching equilibrium. The acceleration of mass balance loss is apparent regardless of datasets used to determine it, including glaciological, geodetic, altimetry, and gravimetric observations (The GlaMBIE Team 2025). The intercomparison assessment identified that global glaciers annually lost 273+26 gigatons (Gt) in mass from 2000 to 2023, with loss having been 36% greater in the second half than in the first half of this period (The GlaMBIE Team 2025).

In the European Alps, all 49 glaciers reported negative mass balances, with 45 losing over 1 m w.e. All 10 Icelandic glaciers had negative balances. In Svalbard, all seven had negative balances exceeding an exceptional loss of 1.25 m w.e. This was the result of near complete snow cover loss across most glaciers (Fig. 2.20) following record temperatures in August (see section 7f5 for details). Twelve of the 13 glaciers from Norway and Sweden had mass losses of more than 1.0 m w.e.

High snow line persisted through the winter on Mount Everest glaciers.

Across High Mountain Asia, 20 of 21 glaciers, reporting from seven nations, had negative balances. The highest average losses were in the Himalayas of Nepal and the lowest in the Pamir Range of Tajikistan.

In the Andes Mountains of South America, all 14 glaciers, reporting from five nations, had negative balances. Conejeras Glacier (Colombia), following a 5.04 m w.e. loss in 2023, was declared extinct in 2024. The daily hydrograph below this glacier changed from a predominanceof days with a purely melt-driven hydrograph from 2006 to 2016 to an increase in the frequency of days with flows less influenced by melt after 2016 (Morán-Tejeda et al. 2018).

All 16 glaciers in North America had negative balances. All four glaciers in Arctic Canada had mass balance losses under 1 m w.e. In western Canada and Washington and Montana (United States), all 16 glaciers reporting had losses exceeding 1 m w.e. The Ice Worm Glacier (Washington) was listed as extinct in 2023 after 40 years of continuous observations (Pelto 2024). In 2024, loss from the relict ice (ice that is no longer moving or part of a glacier) was 2.4 m and melt runoff below the glacier had decreased similar to Conejeras Glacier (Pelto and Pelto 2025). In Alaska, all three glaciers had mass balance losses. Davies et al. (2024) examined the Juneau Icefield, the most observed icefield in Alaska in terms of mass balance, and found an acceleration of mass loss with a doubling after 2010 compared to 1979–2010.

Easton Glacier, Washington extensive retreat since 1990, with last five years being the most rapid. Terminus and mass balance surveyed annually and reported to WGMS.

Alpine annual mass balance glaciological observations are reported to the World Glacier Monitoring Service (WGMS) by national representatives with a 1 December annual submission deadline. WGMS reference glaciers have at least 30 continuous years of mass balance observa-tion. Benchmark glaciers have at least a 10-year mass balance record and are in regions that lack sufficient reference glaciers. The combination of benchmark and reference glaciers is used to generate regional averages (WGMS 2023). Global values are calculated using a single averaged value for each of 19 mountain regions, limiting bias from observed regions (WGMS 2023). As this dataset expands, the annual values are reanalyzed and updated.

The lack of snow pack at the end of summer is evident across Edgeoya in Svalbard, blow a closeup of Digerfonna further illustrates with lettered points indicating new bedrock areas that are expanding amidst the ice cap.

Grosser Aletsch Glacier Rapid Snow Loss June 2026

On By mspeltoIn climate change glacier retreat, switzerland glacier retreat
Snow line in Sentinel images from June 2026 at 2450 m on June 11 and at 2850 m on June 27th.

In June of 2025 heat waves combined with limited winter snowpack set the stage for significant glacier loss, 3% of the volume of Swiss Glacier. This followed on the exceptional losses in 2022 and 2023.

This same story in playing out through June of 2026, which will lead to this being the fourth year in the last five with exceptional glacier mass balance loss. On Grosser Aletsch Glacier on June 11th the snow line on the glacier was at 2450 m. By June 24th it had risen to 2800 m and by June 25th/27th 2850-2900 m. This is similar to the rapid rise of 400 m observed on Argentiere Glacier, France.

Grosser Aletsch Glacier snow line on June 25, 2026 averages 2850 m in this Landsat image.

The snow line rose to a record high 3200 m in 2022, and reached in 3100 m in 2025. Will 2026 set a new record? The snow line is not as high as the same date in 2022, though within ~25 m, but higher than late June 2025.

Above the late June snow line on Grosser Aletsch Glacier in 2022 and 2025 in Sentinel images. These two years had extensive June heat waves after winters with low snowpack. At the end of summer the snow line had risen to 3200 m in 2022 and 3100 m in 2025.

Glaciar Mayo, Argentina Terminus Collapsing in 2026: A Familiar Pattern

On By mspeltoIn argentina glacier retreat, climate change glacier retreat, Glacier Observations
Glaciar Mayo terminus change from November 2025 to February 2026 illustrated in Sentinel images. The yellow dots indicate the margin, which has retreated on both sides forming a melange (M) and new icebergs (I).

Glaciar Mayo, Argentna in Los Glaciares National Park is an eastern outlet of the Southern Patagonia Ice Cap. The glacier has terminated on the northern shore of a glacial lake for the last 35 years. The mass balance from 1975-2011 was identified as slightly positive by Schaefer et al (2015). This enabled the glacier to terminate on the northern shore of a glacial lake, an arm of Lago Argentino from 1984-2020. From 2000-2019 Minowa et al (2021) noted that Glaciar Mayo had transitioned to a negative balance and overall thinning. This thinning is what has led to the terminus beginning to collapse into the lake.

The terminus tongue projecting into the lake had been 2.5 km2, had now declined to 1.4 km2. The terminus along the northern shore had been 2000 m wide and is now 1150 m wide. There is further crevassing/rifting that suggests the glacier tongue is not done thinning in 2026. This continues to be an active year for calving retreat in Patagonia as seen at Upsala and Jorge Montt Glacier, see below.

Glaciar Mayo terminus change from November 2025 to February 2026 illustrated in Landsat images. The yellow dots indicate the margin, which has retreated on both sides forming a melange (M) and new icebergs (I).
Jorge Montt Glacier retreat from 2021-2026 with a particularly extensive and packed melanage in 2026, observed in Sentinel images.
Tyndall Glacier 2 km retreat from 2022-2025 continues with heavily crevassed terminus front indicating an active calving retreat will continue in these Sentinel images. The terminus front is noticably higher above the water indicating thicker ice and likely deeper water.
Upsala Glacier had a burst of calving in Feb. 2026. The comparison to 2021 highlights both the retreat, separation from Bertachhi Glacier and substantial drainage of Lago Guillermo.

Videla Glacier, Chile Retreat Generating Lake Expansion 1997-2025

On By mspeltoIn chile glacier melt, chile glacier retreat, climate change glacier retreat, Glacier Observations
Videla Glacier, Chile is an outlet glacier of the Cordillera Darwin Icefield. The glacier has a number (Point 1-6) of terminus lobes where retreat has led to proglacial lake development between 1997 and 2025, as seen in these annotated Landsat images.

Videla Glacier is a land terminating glacier in the northwest portion of the Cordillera Darwin Icefield (CDI) in Tierra del Fuego, Chile. The glacier has terminates in several expanding proglacial lakes each in front of a different tongue of the glacier. The glacier flows northwest from Cerro Ambience towards Fiordo Profundo.  Meier et al (2018) identified area change of Patagonia glaciers from 1870-2016 with a ~16% area loss of CDI, with more than half of the loss occurring since 1985. They also noted that CDI glaciers were retreating fastest between 1986 and 2005. Izagirre et al (2025) identified a 124% increase in glacier lake area from retreat between 1945 and 2024. The retreat has been largest on tidewater glaciers such as Marinelli Glacier and Ventisquero Grande Glacier.

In 1997 of Videla Glacier’s six main terminus lobes, five did not exhibit a proglacial lake, only the two northern most lobes (Point 4, 5, and 6) ending in a fringing yet to develop proglacial lake. The terminus lobes at Point 2 and 3 were joined. By 2019 lobes 1 and 4 had developed significant proglacial lakes, while the main terminus at Point 5 and 6 had opened up two halves of the same proglacial lake. The terminus lobes at Point 2 and 3 had separated. A rib (yellow arrow) was developing upglacier of the main terminus indicating thinning and reduced flow. A new lake had developed just downstream of this rib.

In 2025 the terminus at Point 1 had receded 950 m creating a 0.75 km2 proglacial lake. Terminus Lobe 2 and 3 had separated by 400 m. At Point 4 a 0.5 km2 proglacial lake had formed with the 1050 m retreat. The main terminus at Point 5 and 6 extends across the lake basin in a narrow 350 m wide tongue. The lake has grown to 3 km2, with 1.5 km of recession from Point 6 and 1.8 km from Point 5. This narrow tongue may well break off this coming summer.

Videla Glacier, Chile ongoing retreat and proglacial lake growth at terminus lobes (1-6) illustrated by Landsat images from 2019 and 2022.

HPS-12, Chile Spectacular Retreat 1985-2025

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

HPS-12 Glacier in 1985 and 2017 Landsat images.  The red arrow indicates 1985 terminus, yellow arrows the 2017 terminus, purple dots the snowline and 1-4 are tributaries.  By 2017 all tributaries have detached and the glacier has retreated 13 km. 

HPS-12 is an unnamed glacier draining the west side of the Southern Patagonia Ice Cap (SPI).  The glacier terminates in a fjord and is adjacent to Upsala Glacier to the east and Pio IX Glacier to the north. This developing fjord is also unnamed but feeds into Estero Falcon. Here we update the 2017 NASA Earth Observatory project I completed in 2017, that identified this as the fastest retreating glacier in Chile in the 1985-2017 period, using Landsat imagery from 1985-2025. 

HPS-12 Glacier in 2015 and 2025 Landsat images.  The red arrow indicates 1985 terminus, yellow arrows the 2025 terminus, black arrow the 2015 terminus. Former tributary 1 and 2 have declined in width . 

 In 1985 the HPS-12 terminates 1.5 km from the junction of two fjords that are occupied by HPS-12 and HPS-13.  These are separated by a peninsula.  The glacier is fed by four tributaries labelled 1-4. The snowline in 1985 is at 900 m.  In 2001 the four tributaries still join the main glacier, but the terminus has retreated 3.5 km.  In 2015 glacier retreat has led to separation of tributary 1, 2 and 4 from the main glacier, tributary 3 only feeds tributary 2 and not the main glacier.    The glacier retreat has continued to 2017, the current terminus is 800 m wide vesus 2800 m wide in 1985 .  Total retreat from 1985 to 2017 was 13 km.  By 2025 the glacier has retreated 14.75 km and has lost more than 50% of its total length. Tributary 1 and 2 continue to narrow from 2015 to 2025 illustrating that flow from the icefield accumulation zone is being reduced. This suggests less discharge into the terminus reach of HPS-12.

This glacier follows the pattern of retreat we have reported from Bernardo Glacier, O’Higgins Glacier, Tyndall Glacier and Upsala Glacier. The retreat is driven by the SPI have been experienced significant mass loss a. Malz et al (2018) noted a ~1 m/year mass loss from 2000-2016 with HPS-12 and Jorg Montt Glacier losing the most. Minowa et al (2021) found that 35% of all ablation of the Patagonia Icefields stemmed from frontal ablation.

HPS-12 Glacier in 2001 and 2015 Landsat images.  The red arrow indicates 1985 terminus, yellow arrows the 2017 terminus, purple dots the snowline and 1-4 are tributaries.  By 2015 tributaries 1, 2 and 4 have detached. 

Rikeva Glacier, Novaya Zemlya 2000-2025 Retreat Releases New Island

On By mspeltoIn climate change glacier retreat, glacier climate change, Novaya Zemlya glacier retreat
Rikeva Glacier retreat in Landsat images from 2020 and 2025. Illustrates new island at Point A and retreat of land terminus at Point B and from headland at Point C.

Rikeva (Rykacheva) Glacier flows from the Northern Novaya Zemlya Ice Cap to the west coast and the Barents Sea. The glacier has been retreating rapidly like all tidewater glaciers in northern Novaya Zemlya (Pelto, 2016) (Carr et al 2014) identified an average retreat rate of 52 m/year for tidewater glaciers on Novaya Zemlya from 1992 to 2010. Maraldo and Choi (2025) identified frontal retreat rate of Novaya Zemlya glaciers from 1931-2021 and found an increased each decade since the early 1970s, reaching a peak retreat rate of 65 m/year between 2011 and 2021. We have observed the impact at Vilkitskogo Glacier and Krayniy Glacier,

In 2000 Rikeva Glacier extended beyond the island that would emerge at Point A. The landbased terminus lobe extended just beyond Point B. By 2013 the glacier had retreated adjacent to the island, with the island acting as a stabilizing point for the terminus. The terminus lobe had retreated just south and east of Point B.

Rikeva Glacier in Landsat images from 2000 and 2013 illustrating retreat to island at Point A and retreat of land terminus at Point B.

In 2018 Rikeva Glacier terminus rested on an island at Point A that acted as a buttress for the glacier terminus. By 2025 the glacier had retreated from the island with 4.5 km2 of glacier retreat since 2018 and 8 km2 of retreat since 2000.

Rikeva Glacier in Sentinel images from 2018 and 2025 illustrates retreat from Island at Point A.