Global database of glacier failures (1900&ndash;2025)

Bashkova, Ekaterina; Rupper, Summer B.; Shugar, Dan H.; Forster, Richard R.

doi:10.5194/essd-2026-481

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https://doi.org/10.5194/essd-2026-481

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10 Aug 2026

| 10 Aug 2026

Status: this preprint is currently under review for the journal ESSD.

Global database of glacier failures (1900–2025)

Ekaterina Bashkova, Summer B. Rupper, Dan H. Shugar, and Richard R. Forster

Abstract. Glacier failures, including ice avalanches, glacier detachments, and rock-ice avalanches associated with glacier structural instability, are gravity-driven failures of glacier ice on mountain slopes. These events can initiate cascading processes with significant downstream impacts on populations and infrastructure. Ongoing atmospheric warming alters glacier geometry, thickness, and basal conditions, affecting the frequency, distribution, and mechanisms of glacier-related failures. Cataloging glacier failures is therefore important for hazard assessment in mountain regions undergoing rapid change. However, observational records are limited, and most studies focus on individual events. Beyond local-scale studies, triggers and impacts have not been systematically documented or analyzed, and events are rarely linked to their source glaciers through existing glacier inventories. To address this issue, we present a global database of glacier failures across all mountain regions outside Greenland and Antarctica, spanning 1900 to 2025. The database was compiled from scientific articles, technical reports, hazard inventories, and verified media sources. It includes 502 events from 228 glaciers across 11 Randolph Glacier Inventory regions and links each hazardous glacier to its inventory ID. The database contains 25 attributes describing event location, timing, type, reported triggers, and downstream impacts. The spatio-temporal analysis shows a strong reporting bias, with most events concentrated in well-monitored territories, although actual differences in hazard types persist across regions. The analysis indicates two major shifts toward higher reported event counts, occurring in the mid-1960s and early 2010s. Glacier failures exhibit visible seasonal patterns, with a pronounced summer peak in the Northern Hemisphere and a weaker seasonal signal in the Southern Hemisphere, both of which are consistent with periods of high meltwater input. Triggers and environmental factors indicate that glacier failures often result from combinations of conditions rather than a single process, with meltwater acting as a key modulator. Reported impacts range from no consequences to high-mortality events, with large regional differences largely determined by downstream exposure. The database provides a basis for analysis of glacier failure patterns and supports hazard assessment under changing climatic conditions, and is publicly available at Zenodo [https://doi.org/10.5281/zenodo.19477908] (Bashkova and Rupper, 2026).

Received: 20 Jun 2026 – Discussion started: 10 Aug 2026

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Ekaterina Bashkova, Summer B. Rupper, Dan H. Shugar, and Richard R. Forster

Status: final response (author comments only)

RC1:
'Comment on essd-2026-481', Anonymous Referee #1, 28 Aug 2026

Dear editor and authors,
Please find below my comments on the manuscript titled “Global database of glacier failures (1900-2025)” by Ekaterina Bashkova et al.
The authors compile a database of glacier failures spanning 125 years across glacierized regions outside the polars. The manuscript is comprehensive in terms of event compilation, database structure, and subsequent analyses. In particular, it highlights the predominantly summer seasonality of glacier failures worldwide, the accelerated increase in reporting rates in the 1960s and the 2010s, and the multifactorial mechanisms that trigger these events.
However, some aspects require clarification or have some confusions. The authors exclude the well-known 1970 Huascarán event and the 2021 Chamoli event because these events were primarily initiated by failures of the underlying bedrock, which subsequently mobilized the overlying glacier ice. Nevertheless, bedrock instability may itself be closely linked to long-term glacier thinning and melting, as well as freeze–thaw processes. Although the relative contributions of these factors or whether rock or ice primarily controlled the failure, cannot be readily quantified, excluding such famous events may undermine the credibility of the database. Furthermore, a related issue concerns the term “rock-ice avalanche”. If the authors intend to emphasize glacier-dominated failures, “ice-rock avalanche” may be more appropriate.
Overall, this is a valuable and well-developed contribution. I recommend acceptance after minor revision.

Citation: https://doi.org/10.5194/essd-2026-481-RC1
- AC1:
  'Reply on RC1', Ekaterina Bashkova, 26 Oct 2026
  The authors thank the reviewer for the positive review and constructive criticisms. We respond to the two criticisms below (the exclusion of some bedrock failure events and the use of rock-ice versus ice-rock avalanches).
  Exclusion of failure events triggered by underlying bedrock instability.
  
  We agree that the well-known 1970 Huascarán and 2021 Chamoli events are highly valuable for understanding complex glacier-related hazards in mountain environments. We also acknowledge that bedrock instability may be influenced by long-term glacier thinning and melting, as well as freeze-thaw processes. As the reviewer notes, determining whether rock or ice primarily controlled the failure can be very challenging for some events.
  At the same time, our study is designed to focus specifically on processes directly associated with glacier structural instability (lines 7-8) and glacier flow (Cuffey and Paterson, 2010; lines 80-82), rather than on all mass movements involving glacier ice. As described in lines 91-93, we applied specific criteria to distinguish events based on their failure mechanisms. We marked the uncertainties associated with event classification, including cases where the hazard type or the primary failure mechanism is unclear (lines 93-94; 283-285).
  For events initiated by bedrock failure, geological characteristics such as joints, foliation, and faults may play a major role in determining the location and mechanism of failure (Evans et al., 2009; Shugar et al., 2021). Including these events would introduce a distinct failure mechanism into our dataset and make it harder to identify the factors controlling glacier instability.
  We do not want to diminish the importance of these devastating events or their possible connection to ice instability. In the revised manuscript, we expand the Discussion (Section 4.5) to mention the August 2026 Rasuwa disaster in Nepal alongside the 1970 Huascarán and 2021 Chamoli disasters. We clarify that these events are not included in the current version of the database because they were initiated by bedrock failure rather than failure of the glacier itself, although the role of glacier processes in bedrock failure remains uncertain in some cases. Future research may clarify whether glacier dynamics initiated individual events; this should support the inclusion of such events in future versions of the inventory. Despite their current exclusion from our inventory, these events illustrate the destructive potential of mass movements involving both bedrock and glacier ice and should receive appropriate attention in this manuscript on mass movements in mountain environments.
  Using the term “ice-rock avalanche” instead of “rock-ice avalanche”.
  
  We have not identified a clear distinction between these terms based on the failure's initiation mechanism, although we agree that the reviewer’s suggestion is logically reasonable. The literature specifically cited in this study (e.g., Huggel et al., 2005; Schneider et al., 2011; Kääb et al., 2021; Leinss et al., 2021, among others) most commonly uses the term “rock-ice avalanche” (RIA). Based on the reviewer's comment, we searched for studies that specifically use the term "ice-rock avalanche." We identified several publications that use the term “ice-rock avalanche” in their titles (e.g., Ahmed et al., 2026; Wang et al., 2025; Chu et al., 2026; Liang et al., 2026). However, the authors use both terms (rock-ice and ice-rock) interchangeably in the text, without distinguishing between them by failure mechanism. We therefore understand that the terms “rock-ice avalanche” and “ice-rock avalanche” are often used interchangeably in the literature, but without regard to mechanism.
  It is worth noting that the proportions of ice and rock in the mass flow may also influence whether an event is described as a “rock-ice avalanche” or an “ice-rock avalanche.” This raises the question of whether we should name these events based on what caused the failure or on whether the resulting flow contains more ice or rock.
  Since the main body of literature used to motivate this study, and included in the citation list, predominantly uses the term RIA, we prefer to retain this term to maintain consistency with the terminology used in the literature.
  
  References:
  Evans, S. G., Bishop, N. F., Fidel Smoll, L., Valderrama Murillo, P., Delaney, K. B., & Oliver-Smith, A. (2009). A re-examination of the mechanism and human impact of catastrophic mass flows originating on Nevado Huascarán, Cordillera Blanca, Peru in 1962 and 1970. Engineering Geology, 108, 96–118. https://doi.org/10.1016/j.enggeo.2009.06.020
  Shugar, D. H., Jacquemart, M., Shean, D., Bhushan, S., Upadhyay, K., Sattar, A., Schwanghart, W., McBride, S., Van Wyk de Vries, M., Mergili, M., Emmer, A., Deschamps-Berger, C., McDonnell, M., Bhambri, R., Allen, S., Berthier, E., Carrivick, J. L., Clague, J. J., Dokukin, M., … Westoby, M. J. (2021). A massive rock and ice avalanche caused the 2021 disaster at Chamoli, Indian Himalaya. Science, 373(6552), 300–306. https://doi.org/10.1126/science.abh4455
  Huggel, C., Zgraggen-Oswald, S., Haeberli, W., Kääb, A., Polkvoj, A., Galushkin, I., & Evans, S. G. (2005). The 2002 rock/ice avalanche at Kolka/Karmadon, Russian Caucasus: Assessment of extraordinary avalanche formation and mobility, and application of QuickBird satellite imagery. Natural Hazards and Earth System Sciences, 5, 173–187. https://doi.org/10.5194/nhess-5-173-2005
  Schneider, D., Huggel, C., Haeberli, W., & Kaitna, R. (2011). Unraveling driving factors for large rock–ice avalanche mobility. Earth Surface Processes and Landforms, 36, 1948–1966. https://doi.org/10.1002/esp.2218
  Kääb, A., Jacquemart, M., Gilbert, A., Leinss, S., Girod, L., Huggel, C., Falaschi, D., Ugalde, F., Petrakov, D., Chernomorets, S., Dokukin, M., Paul, F., Gascoin, S., Berthier, E., & Kargel, J. S. (2021). Sudden large-volume detachments of low-angle mountain glaciers – more frequent than thought? The Cryosphere, 15, 1751–1785. https://doi.org/10.5194/tc-15-1751-2021
  Leinss, S., Bernardini, E., Jacquemart, M., & Dokukin, M. (2021). Glacier detachments and rock-ice avalanches in the Petra Pervogo range, Tajikistan (1973–2019). Natural Hazards and Earth System Sciences, 21, 1409–1429. https://doi.org/10.5194/nhess-21-1409-2021
  Ahmed, R., Bhardwaj, A., Sam, L., & Van Tricht, L. (2026). Ice-rock avalanches in a warming Himalaya indicate pathways toward effective preparedness. Communications Earth & Environment, 7, Article 217. https://doi.org/10.1038/s43247-026-03352-y
  Wang, Q., Li, B., Xing, A., Liu, Y., & Zhuang, Y. (2025). A 15-year history of repeated ice-rock avalanches from a single source area in the Qinghai-Tibet Plateau. Landslides, 22(1), 235–253. https://doi.org/10.1007/s10346-024-02355-0
  Chu, D., Liu, L., & Wang, Z. (2026). The evolution and impact of glacier and ice-rock avalanches in the Tibetan Plateau with Sentinel-2 time-series images. GeoHazards, 7(1), Article 10. https://doi.org/10.3390/geohazards7010010
  Liang, J., Luo, S., & Zhu, K. (2026). Freeze–thaw effects on baffle friction in ice–rock avalanche mitigation: Experiments and numerical simulations. Water, 18(18), Article 2237. https://doi.org/10.3390/w18182237
  
  Citation: https://doi.org/10.5194/essd-2026-481-AC1
RC2:
'Comment on essd-2026-481', Anonymous Referee #2, 25 Sep 2026

Dear editor and authors,

The authors have compiled a global database of glacier failures spanning 1900–2025, with 25 attributes describing glacier identifiers, event locations, timing, event types, reported triggers, and downstream impacts. It documents 502 events from the 228 glaciers across 11 RGI region, showing that glacier failures occur more frequently during the summer season in the Northern Hemisphere, while a weaker seasonal signal is observed in the Southern Hemisphere. The conditioning factors and triggering mechanisms of glacier failure events are discussed in as much detail as possible, considering the limited reporting available. This database provides a useful foundation for future research and hazard assessment in glaciated mountain regions.

Specific comments:

1. If the authors want to add one more event from Nepal, they can consider the event that occurred at Kobang in March 2022, at the same location, this could be added to the database in a future version.
2. It would also be valuable to mention the very recent event in Nepal. This is a major event where the connection with glacier failure has been discussed, and there is still some debate among researchers about whether it should be classified as a rock-ice avalanche. However, it is clear that a glacier collapsed, and an event of this scale is worth mentioning somewhere in the manuscript, even if it is not included in the database at this point.
3. Line 187; Figure 2: The positioning of the labels should be made as consistent as possible. For example, the 46.9% label in the South America donut is touching the outer boundary, whereas the corresponding label for New Zealand is positioned inside the donut. Please make the label positioning more uniform throughout the figure where possible.
4. Lines 369-434: Discuss a bit more about reliability and completeness of the historical datasets.
5. Lines 447-448: The manuscript mentions two main shifts in reporting frequency, around the mid-1960s and a stronger increase after 2010, in several places. A dedicated paragraph discussing the significance of these changes would be useful. Some effort is seen in the conclusion however, relevant literature inclusion is encouraged to support the discussion and help explain whether these changes are related mainly to reporting and observational capacity or may also reflect changes in glacier-related hazards.
6. Line 627-672: The Discussion section should be strengthened. If necessary subdivide this section and include more literature and modelling studies from well-studied regions such as European Alps. In particular, discuss how the database can support these existing studies and future modelling efforts. Rather than only describing future prospects, the discussion could be more closely connected to existing literature and explain how this database can contribute to future research.

Overall, the manuscript is timely and addresses an important aspect of mountain hazards. The database could support future research on glacier instability, cascading hazards, and changing. I recommend acceptance after minor revision.

Citation: https://doi.org/10.5194/essd-2026-481-RC2
- AC2:
  'Reply on RC2', Ekaterina Bashkova, 26 Oct 2026
  We thank the reviewer for the careful review and constructive feedback on our manuscript, and we believe the resulting revision has greatly improved the manuscript. We provide a point-by-point response to each of the reviewer's comments below.
  Specific comments:
  If the authors want to add one more event from Nepal, they can consider the event that occurred at Kobang in March 2022, at the same location, this could be added to the database in a future version.
  
  Many thanks for pointing out this event. We will add it to the current version of the database, which will be updated alongside the revised manuscript. It will be a great contribution to understanding the recurrence of such events at the same hotspots.
  It would also be valuable to mention the very recent event in Nepal. This is a major event in which the connection to glacier failure has been discussed, and there is still some debate among researchers about whether it should be classified as a rock-ice avalanche. However, it is clear that a glacier collapsed, and an event of this scale is worth mentioning somewhere in the manuscript, even if it is not included in the database at this point.
  
  We thank the reviewer for the suggestion. We include a discussion of this event and agree that it is reasonable to mention it in the context of mountain hazards associated with glaciers. In the revised manuscript, we expanded the Discussion (Section 4.5) to mention the August 2026 Rasuwa disaster in Nepal alongside the 1970 Huascarán and 2021 Chamoli disasters.
  Line 187; Figure 2: The positioning of the labels should be made as consistent as possible. For example, the 46.9% label in the South America donut is touching the outer boundary, whereas the corresponding label for New Zealand is positioned inside the donut. Please make the label positioning more uniform throughout the figure where possible.
  
  Many thanks for the careful review of the figures. We adjusted the label positions throughout Figure 2 to make them more consistent.
  Lines 369-434: Discuss a bit more about reliability and completeness of the historical datasets.
  
  We thank the reviewer for the recommendation. Rather than addressing this question in Section 3.2.2, we assess the reliability and completeness of historical records in the expanded Discussion (Section 4.2) of the revised manuscript, using our dataset as an example. This analysis outlined changes in the precision of historical records across defined periods (updated Section 3.2.2), noting that these differences indicate not only the age of the records but also the methods used to observe events and shifts in research activity across regions. We appreciate the reviewer’s suggestion, which helped us strengthen this part of the Discussion.
  Lines 447-448: The manuscript mentions two main shifts in reporting frequency, around the mid-1960s and a stronger increase after 2010, in several places. A dedicated paragraph discussing the significance of these changes would be useful. Some effort is seen in the conclusion however, relevant literature inclusion is encouraged to support the discussion and help explain whether these changes are related mainly to reporting and observational capacity or may also reflect changes in glacier-related hazards.
  
  We thank the reviewer for pointing this out. We have revised the structure of the Discussion and added a dedicated subsection (Section 4.3) to the revised manuscript that examines the identified peaks in reporting frequency in greater detail. This analysis has allowed us to better interpret the observed changes, which we discuss in relation to relevant examples from the literature. We appreciate the reviewer’s suggestion, which helped us strengthen this part of the manuscript.
  Line 627-672: The Discussion section should be strengthened. If necessary subdivide this section and include more literature and modelling studies from well-studied regions such as European Alps. In particular, discuss how the database can support these existing studies and future modelling efforts. Rather than only describing future prospects, the discussion could be more closely connected to existing literature and explain how this database can contribute to future research.
  
  We agree with this comment and have added a dedicated subsection in Discussion (Sections 4.4 and 4.5) to better explain how the database can support existing hazard assessments and future modeling efforts.
  
  Thank you for the positive review and for helping us strengthen the manuscript.
  
  Citation: https://doi.org/10.5194/essd-2026-481-AC2

Ekaterina Bashkova, Summer B. Rupper, Dan H. Shugar, and Richard R. Forster

Data sets

Global database of glacier failures (1900-2025) Ekaterina Bashkova and Summer B. Rupper https://doi.org/10.5281/zenodo.19477908

Ekaterina Bashkova, Summer B. Rupper, Dan H. Shugar, and Richard R. Forster

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Short summary

Glacier failures release large amounts of ice that travel downslope very fast. It can have serious consequences for people and infrastructure. We collected information on more than 500 glacier failures worldwide to understand where and when they occur. Reported events are concentrated in regions with better observations and increased after the mid-1960s and early 2010s. This record helps us better understand such events in a changing climate and supports future monitoring and risk preparation.


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