Item: SNOW-AVALANCHE PROTECTION MEASURES PUT TO TEST IN SEVERAL AVALANCHE CYCLES IN NW- AND N-ICELAND IN MARCH 2026
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Title: SNOW-AVALANCHE PROTECTION MEASURES PUT TO TEST IN SEVERAL AVALANCHE CYCLES IN NW- AND N-ICELAND IN MARCH 2026
Proceedings: Proceedings, International Snow Science Workshop, Whistler, BC, Canada, 2026
Authors:
- Harpa Grímsdóttir [ Icelandic Meteorological Office, Reykjavík, Iceland ]
- Tómas Jóhannesson [ Icelandic Meteorological Office, Reykjavík, Iceland ]
- Óliver Hilmarsson [ Icelandic Meteorological Office, Reykjavík, Iceland ]
Date: 2026-09-28
Abstract: In response to catastrophic avalanche accidents in Icelandic settlements in 1995, a government programme was initiated to build protection measures for settlements at risk. More than 70 snow avalanches have hit deflecting and catching dams and braking mounds in Iceland since the start of the programme, giving valuable knowledge on the effectiveness of different types of protection structures and avalanche dynamics. Most recently, severe avalanche cycles on 15–19 and 23–27 March 2026 involved snow avalanches that impacted braking mounds in Bolungarvík and at Seljalandshlið in Ísafjörður, both in NW-Iceland. Three avalanches hit braking mounds below Innra-Bæjargil and an avalanche flowed along the entire length of the 700-m-long deflecting dam below Skollahvllf at Flateyri in NW-Iceland. Avalanches hit deflecting dams below Jörundarskál and Strengsgil in N-Iceland and were successfully deflected. Finally, an avalanche was stopped by a catching dam and flowed along a deflecting dam at Patreksfjörður in NW-Iceland. None of the avalanches overran the protection measures, and nobody came to harm. No avalanches were released from a starting area with snow supporting structures in Hafnahryrna in Siglufjörður during these cycles when several avalanches, some large, were released from neighbouring avalanche paths with similar aspects. It appears likely that the protection measures prevented snow avalanches from reaching the respective settlements in both Patreksfjörður and Siglufjörður in this case. The avalanches that have impacted braking mounds, deflecting dams and catching dams in Iceland provide important empirical data about the effectiveness of avalanche protective structures. Rapidly moving fluidized fronts have overflowed dams in two cases, causing damage. In addition to improving the safety of inhabitants, the protection structures reduce the frequency of evacuations. It is clear that widespread evacuations would have been ordered in the March 2026 avalanche cycles if the protection measures that have been implemented in Iceland during the last quarter century had not been in place.
Object ID: ISSW2026_P1.42.pdf
DOI: https://doi.org/10.15788/1790098806
Language of Article: English
Presenter(s): Harpa GrÃmsdóttir
Keywords: Avalanche protection measures, avalanche dams, avalanche cycles
Page Number(s): 1501 - 1506
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