Tropical glaciers in the Cordillera Real (Bolivia) are rapidly retreating. In the early 2000s, it was predicted that many of its small glaciers (<0.5 km2) would vanish within a few decades. More than two decades after this dire prediction, we evaluate their fate using a recently published, multitemporal inventory of glaciers in the Cordillera Real. We identify 174 glaciers that disappeared between 1998 and 2024, more than five times the number previously reported. All of the glaciers that vanished were small, as predicted, and most (79.9%) were low-lying (maximum elevation <5400 m). These losses represent 30.5% of the total number of glaciers in the Cordillera Real in 1998, but their demise accounts for only 8.5% of the total area loss between 1998 and 2024. Although a majority (62.7%) of small glaciers persist to 2024, current and projected warming will likely threaten most of those that remain.
Ice sheets leave contact with the bed at grounding lines, beyond which floating ice shelves experience no friction at their base. In places where basal friction begins to decrease upstream of the grounding line, ice sheets respond more strongly to climate forcing. However, the spatial extent of zones of low grounding line friction is poorly constrained by observations. Here, we use a steady-state model of marine-terminating ice stream flow to show that the location where basal friction begins to weaken upstream of the grounding line is accompanied by a prominent surface slope break. We then use observations of grounding zone features around the Antarctic Ice Sheet derived from ICESat-2 laser altimetry to find the displacement between grounding line locations determined from SAR flexure measurements and such surface slope break points. We find widespread evidence of decreasing friction hundreds to thousands of meters upstream of grounding lines around the Antarctic Ice Sheet, indicating that grounding lines may be more sensitive to forcing than typically assumed in ice sheet models where friction does not decrease upstream of the grounding line. We suggest that such an observational approach should be used to parameterize grounding line friction interpolation schemes in ice sheet models.
Small glaciers (< 0.5 km(2)), glacierets (< 0.25 km(2)) and, in particular, very small glacierets (< 0.01 km(2)), despite being numerous in mountain environments, are underrepresented in scientific inquiry when assessing their response to climate change. We present new insights into the vanishing (no visible surface ice whilst underlain by bedrock or water) of 77 very small glacierets distributed in the Northern and Central Andes of Chile. We also analyse the presumable vanishing (no visible surface ice whilst underlain by regolith) of 244 additional very small glacierets, comprising a total dataset of 321 very small glacierets within the study area, equivalent to the loss of 5.69 & times; 10(6 )m(3) of water equivalent ice volume according to the 2022 Chilean Public Glacier Inventory. Our results show that 45.5% of the sample shrank from individually small glaciers at the beginning of the 21st century, whereas 53.0% of the sample vanished after being fragmented from larger glaciers in the same time span. The observed generalised reduction behaviour and vanishing results after extremely dry conditions at the end of the 2009-2022 Central Andes megadrought. We discuss our results in terms of the minimum area threshold for classifying very small glacierets, and whether their vanishing poses a hydrological impact.
Tropical glaciers have undergone significant shrinkage or complete disappearance due to climate change. Based on geodetic observations and remote sensing data, this study presents a comprehensive chronology of the extinction of Carihuairazo Ice Cap (Kari-Huayra-Razu in Quichua), located in the Ecuadorian Andes, from 1956 to 2020. The cumulative glacier mass balance over the 1956-2020 period was - 31.40 m w.e. (-0.49 +/- 0.04 m w.e. a-1), determined over three periods of ice loss 1956-2005, 2005-2011, and 2011-2020, during which the annual average mass balance was - 0.41, - 0.77 and - 0.75 m w.e. a-1, respectively. The loss of glacier mass led to total glacier shrinkage, with a pronounced acceleration between 1978 and 1986, after which the glaciers retreated rapidly and disappeared by 2024. The ice cap experienced an average annual area loss of 3 % a-1 since the 1980s, a trend two times as high as that reported for the Antisana Ice Cap during a similar period.
We present a high-resolution dataset of over one million icequakes located just upglacier of the grounding line of Rutford Ice Stream, West Antarctica, spanning a 23 day period during January 2019. The icequakes were identified and located initially using the QuakeMigrate software, and their locations can be refined using the GrowClust software. These two tools naturally complement one another: QuakeMigrate detects and locates large numbers of events, while GrowClust enhances location precision by relocating events using QuakeMigrate's robust picks and locations. To support this workflow, we introduce QuakeSupport, a supplementary package developed to facilitate and extend the use of both tools. Based on our extensive use of QuakeMigrate and GrowClust, we identified common processing needs-automating data preparation, efficiently managing extended QuakeMigrate runs and converting QuakeMigrate outputs for GrowClust-which QuakeSupport addresses through an end-to-end workflow. By reducing the learning curve and improving processing efficiency, QuakeSupport enables researchers to focus on scientific analysis. Together with the Rutford dataset, this integrated and scalable approach demonstrates a framework for generating (cryo)seismic event catalogs in the era of increasingly larger seismic data volumes.
The Echaurren Norte Glacier mass balance time series is the longest in the Southern Hemisphere, thus it is-together with the Zongo Glacier in Bolivia-a reference glacier by the World Glacier Monitoring Service. The Echaurren Norte Glacier constitutes a reference case of glacier degradation and transition in the Central Andes of Chile, exemplifying the full spectrum of contemporary glacier evolution processes: frontal retreat, surface thinning, progressive debris cover and fragmentation. An analysis of satellite imagery from 1955 to 2023 reveals a similar to 65% reduction in glacier area, accompanied by an expansion of supraglacial debris. Today, no clean ice is visible at the surface, and the glacier persists as three fully debris-covered units with a combined area of only 0.18 km2. These transformations indicate a shift from an active mountain glacier towards a debris-covered glacieret, characterized by negligible ice flow and limited basal sliding. In this contribution to the 'Vanishing Glaciers' collection, we present this work as a homage to the Echaurren Norte Glacier and to everyone who contributed to its monitoring over the decades. We also discuss possible pathways to continue long-term glacier monitoring in this region and strategies to link this monitoring to the Echaurren Norte Glacier history.
Helm Glacier is a World Glacier Monitoring Service reference glacier and is one of three glaciers in Western Canada with a mass balance record which exceeds 40 years. An ice-penetrating radar survey reveals a mean and maximum ice thickness of 13.0 and $37.2\,\mathrm{m}$, respectively. We combine ice thickness data and altimetric data from repeat LiDAR surveys to project ice disappearance. We use simple extrapolation and a multivariate linear regression to predict surface elevation change based on incoming shortwave radiation, end-of-winter snow depth, positive degree days, slope and aspect. Both approaches project the disappearance of Helm Glacier by 2035. We estimate that Helm Glacier has a current mass balance sensitivity to temperature of ${\mathrm C}_{\mathrm T}=-0.58\,{\mathrm m\boldsymbol\,\mathrm w.\mathrm e.\boldsymbol\,\mathrm a}<^>{-1}\,<^>\circ\,\mathrm C<^>{-1}$, which is slightly less negative than the balance sensitivity of ${\mathrm C}_{\mathrm T}=-0.64\,{\mathrm m\boldsymbol\,\mathrm w.\mathrm e.\boldsymbol\,\mathrm a}<^>{-1}\,<^>\circ\,\mathrm C<^>{-1}$ derived from the in situ balance record. Helm Glacier is more than 4 $\rm{<^>\circ}C$ out of balance with current climate conditions [2014-24].
Disappearing glaciers are observed worldwide, but a reliable counting is only available for some regions. This is due to several issues, ranging from inconsistent glacier identification to different criteria applied to decide whether or not a glacier has disappeared. The public perception of a glacier being lost usually has a focus on specific, often well-known glaciers, with a related media attention. In contrast, hundreds of glaciers might disappear in other regions over the same period without any notice. When they are not widely known, this silent disappearance can also happen to scientifically valuable glaciers. For example, the loss of benchmark glaciers with decades of mass balance measurements is also a loss of important information about climate variability in remote high-mountain regions. This study gives an overview of the challenges and different criteria used to determine if a glacier has disappeared and presents recommendations for a proper counting and change assessment.
Nordmannsj & oslash;kelen, mainland Europe's northernmost glacier, has fragmented into small remnants, with only one unit showing signs of active ice flow. The glacier has lost 92% of its area since 1970 (September 2024 area relative to 1970 area). It is reduced from 23.5 km2, as an upper bound of its size in similar to 1900, to 0.4 +/- 0.08 km2 in September 2024. Between 1970 and 2020, the geodetic mass balance was -17.6 +/- 1.79 m w.e., corresponding to an average annual mass balance of -0.35 +/- 0.04 m w.e. a-1. The warm summer of 2024 took its toll on Nordmannsj & oslash;kelen and the glacier area was reduced by 1.08 +/- 0.16 km2 from 2023 to 0.4 +/- 0.08 km2 in 2024 (a 68% reduction relative to 2023 area). Similar glacier retreat and thinning are observed elsewhere in the region, and the neighboring Langfjordj & oslash;kelen has mass balance measurements for the period 1989-2024, and the highest mass loss is recorded in 2024.
Marine ice cliff instability (MICI) is the hypothesis that self-sustained retreat of ice sheets can be initiated when sufficiently tall ice cliffs are exposed. Projections, including MICI, suggest a substantial risk of large sea-level rise in the coming centuries. However, to date, the number of modelling studies exploring this possibility is limited. Here, we investigate the role of calving in ice loss and frontal retreat of the Amundsen Sea glaciers, West Antarctica, using a high-resolution ice-flow model. This study employs a cliff-height-dependent calving parametrisation from DeConto and Pollard (2016). Numerical convergence tests reveal that mesh resolutions finer than 2 km are essential for robust simulation of grounding line migration and frontal dynamics. Simulations assuming initial loss of ice shelves show spatially varied glacier response. For tall marine-terminating fronts, initial retreat driven by exposed cliffs is rapidly reversed as ice deformation lowers cliff height. In contrast, the same parametrisation produces frontal retreat in slow-flowing grounded regions where cliff heights presently exceed 80 m. In those regions, however, no such retreat is currently observed. These findings suggest that direct application of this calving scheme both contradicts existing observational evidence and is unlikely to drive sustained frontal retreat in fast-flowing marine-terminating glaciers under current conditions.
We assess ongoing regional glacier loss in the Austrian state of Vorarlberg using a set of manually mapped glacier outlines for 2017, 2020, 2022 and 2023. Vorarlberg has lost about half of its glacierized area since a previous inventory in the mid-2000s. In 2017-23, glacier area was lost at an average rate of 5% per year. Area loss rates at individual glaciers have increased over time but show considerable variability between glaciers and subperiods. Of 30 glaciers previously inventoried, 5 have vanished completely since 2017. We discuss mapping differences due to the variable interpretation of the images by multiple observers and the mapping challenges that arise even with very high-resolution (10 cm) imagery. Processes leading up to the complete loss of glacier ice, mainly increased debris cover and fragmentation into very small features, cause inherent uncertainties in documenting the disappearance of mountain glaciers and ice bodies. We considered criteria that might be used to define terminology and found 16 remaining glacier fragments with crevasses indicating past or current ice flow, which could be considered glaciers rather than ice bodies.
The Zugspitzplatt represents a key high-alpine reference landscape in German geography. Located below the Zugspitze, Germany's highest peak, it still hosts some of the country's small remaining glacier ice reserves. Owing to its long history of scientific observation, high accessibility, and pronounced sensitivity to climatic change, the Zugspitzplatt has acquired emblematic significance as a national reference site for alpine geomorphological and glaciological research. The observation of the Schneeferner glaciers follows a long-standing tradition of glacier monitoring in this region. As of 2022, one of the two glaciers has completely disappeared, and the remaining one is critically endangered. Here, we present geodetic mass balances since 1892 based on historical maps and own surveys. Measurements of ice thicknesses allow the determination of absolute ice masses and their change. From 52 megatons of ice in 1892, less than one megaton was left in 2023 and its disappearance is inevitable. While this deglaciation will have negligible effects on humankind, it represents a potent visual and emotional indicator of climate change. Given the presence of a touristic hotspot and an environmental research station, the Zugspitzplatt has the potential to serve as a focal point for climate education.
An alpine glacier below Sunlight Peak in northwest Wyoming was first photographically documented in 1893, near the end of the Little Ice Age and during the time of industrialization. Since then, evolving technologies have been applied to observe this glacier and nearby discontinuous permafrost for studies spanning Earth, environmental, and planetary sciences. Surveys in the 21st century indicate negative mass balance coinciding with rising average air temperature. This paper reviews the geological and geophysical data on record for the Sunlight Glacier system, presents new results from a 2023 fieldwork campaign combined with remote sensing analysis and comments on likely scenarios of future evolution for this individual body of ice within a broader alpine cryosphere feeding the watersheds of western North America.
The archaeology of glaciers and ice patches has developed as a distinct new field in response to climate change and the melting of mountain ice. Thousands of artefacts and biological materials, dating back up to 10 000 years are being released from melting ice patches and retreating glaciers, offering unique insight into past human activities in cold environments. This paper examines the historical development of glacial archaeology, the preservation or loss of archaeological material from snow and ice, and the methodological challenges in locating and recovering such finds. Key finds and sites from North America, the Alps and Norway are presented. The emerging history demonstrates that high mountain areas were used more intensively in the past than previously assumed, including during winter. The paper argues that closer collaboration between glacial archaeology, glaciology and palaeoclimate research would be highly beneficial, particularly through joint investigations of the ice at glacial archaeological sites.
Melting alpine ice threatens (pre)historic archaeological sites. Current trends suggest loss of ice will continue. Here, we present recent fluctuations in yearly minimum extent from 2017 to 2024 for three central Norwegian ice patches: Storhornet, Elgh & oslash;a and L & aring;gtangan. We discuss how melting ice affects their archaeological potential and introduce the term ghost patch to describe archaeological ice patch sites no longer containing ice. Future archaeological fieldwork prioritization must account for ice patch to ghost patch transitions. We suggest updated archaeological approaches for a future with less and less ice.
More than just shrinking ice, glaciers are more-than-human entities that have relationships with people, affecting and influencing their behaviour. This paper focuses on the relationship between glaciers and alpinists, a community that experiences their retreat in an intimate and embodied way. Thirty semi-structured interviews with alpinists in the European Alps reveal four relational dynamics shaped by disappearing glaciers: awareness leading to technical adaptation, avoidance of increasingly unstable areas, responses to loss, and the enduring pleasure of the encounter. These dynamics shed light on the mourning processes experienced by alpinists in response to the disappearance of the glaciated environment, which can be understood as a form of ecological grief. This mourning has an ambivalent potential: it can lead to a never-ending state of melancholia or, when combined with residual pleasure and attachment, it can foster leadership in climate action and support the development of new relationships with the deglaciated mountain landscape.
