Analysis of an artificially triggered avalanche at the nepheline syenite mine on Stjernøya, Alta, Northern Norway

Since 1961, a Nepheline Syenite mine is operated on the island of Stjernøya in the Altafjord, Northern Norway. The facilities are located in Lillebukt, on the southern side of the island. Above the facilities, the Nabbaren mountain is rising to a height of 727 m a.s.l. Rockfall during summer season...

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Main Authors: Frauenfelder, Regula, Jónsson, Árni, Lied, Karstein, Schwerdtfeger, Dirk, Bergum, Guro, Bühler, Yves, Stoffe, Lukas
Format: Article in Journal/Newspaper
Language:English
Published: Montana State University Library 2014
Subjects:
Online Access:https://hdl.handle.net/11250/3083292
https://arc.lib.montana.edu/snow-science/item/2134
id ftngi:oai:ngi.brage.unit.no:11250/3083292
record_format openpolar
spelling ftngi:oai:ngi.brage.unit.no:11250/3083292 2023-10-09T21:54:27+02:00 Analysis of an artificially triggered avalanche at the nepheline syenite mine on Stjernøya, Alta, Northern Norway Frauenfelder, Regula Jónsson, Árni Lied, Karstein Schwerdtfeger, Dirk Bergum, Guro Bühler, Yves Stoffe, Lukas 2014 application/pdf https://hdl.handle.net/11250/3083292 https://arc.lib.montana.edu/snow-science/item/2134 eng eng Montana State University Library The International Snow Science Workshop (ISSW) Proceedings; https://hdl.handle.net/11250/3083292 https://arc.lib.montana.edu/snow-science/item/2134 8 Avalanche-RnD Snøskred-FoU Chapter 2014 ftngi 2023-09-20T22:48:33Z Since 1961, a Nepheline Syenite mine is operated on the island of Stjernøya in the Altafjord, Northern Norway. The facilities are located in Lillebukt, on the southern side of the island. Above the facilities, the Nabbaren mountain is rising to a height of 727 m a.s.l. Rockfall during summer season and snow avalanches during wintertime pose potential hazards from its slopes. Due to this setting, the mining company has long experience with both physical and non-physical hazard mitigation measures. Apart from physical installations against rockfall and snow avalanches, artificial triggering of the Nabbaren avalanche forms part of this mitigation strategy.The winter of 2013/2014 was characterized by an unusual snow scarcity between December 2013 and March 20, 2014. After this date, large amounts of snow fell during a short period. Due to this new snow loading, together with intensive snowdrift, the mining company decided to artificially trigger the Nabbaren avalanche on April 8, 2014. A D4 slab avalanche was released, subsequently evolving into a mixed dry avalanche of impressive scale. In contrast to avalanches triggered in other years, this avalanche overtopped the avalanche deflecting wall at its one end causing slight damages to some of the factory installations. In order to document the avalanche, an on-site study was carried out shortly after the event. In addition, a WorldView-1 panchromatic satellite image was obtained to map the non-accessible parts of the avalanche. Here, we present findings from the field visit, from image analyses and first modellings of the avalanche run-out. Article in Journal/Newspaper Northern Norway Stjernøya Norwegian Geotechnical Institute (NGI) Digital Archive Alta Lillebukt ENVELOPE(22.107,22.107,70.257,70.257) Nabbaren ENVELOPE(22.597,22.597,70.273,70.273) Norway Stjernøya ENVELOPE(16.415,16.415,76.536,76.536)
institution Open Polar
collection Norwegian Geotechnical Institute (NGI) Digital Archive
op_collection_id ftngi
language English
topic Avalanche-RnD
Snøskred-FoU
spellingShingle Avalanche-RnD
Snøskred-FoU
Frauenfelder, Regula
Jónsson, Árni
Lied, Karstein
Schwerdtfeger, Dirk
Bergum, Guro
Bühler, Yves
Stoffe, Lukas
Analysis of an artificially triggered avalanche at the nepheline syenite mine on Stjernøya, Alta, Northern Norway
topic_facet Avalanche-RnD
Snøskred-FoU
description Since 1961, a Nepheline Syenite mine is operated on the island of Stjernøya in the Altafjord, Northern Norway. The facilities are located in Lillebukt, on the southern side of the island. Above the facilities, the Nabbaren mountain is rising to a height of 727 m a.s.l. Rockfall during summer season and snow avalanches during wintertime pose potential hazards from its slopes. Due to this setting, the mining company has long experience with both physical and non-physical hazard mitigation measures. Apart from physical installations against rockfall and snow avalanches, artificial triggering of the Nabbaren avalanche forms part of this mitigation strategy.The winter of 2013/2014 was characterized by an unusual snow scarcity between December 2013 and March 20, 2014. After this date, large amounts of snow fell during a short period. Due to this new snow loading, together with intensive snowdrift, the mining company decided to artificially trigger the Nabbaren avalanche on April 8, 2014. A D4 slab avalanche was released, subsequently evolving into a mixed dry avalanche of impressive scale. In contrast to avalanches triggered in other years, this avalanche overtopped the avalanche deflecting wall at its one end causing slight damages to some of the factory installations. In order to document the avalanche, an on-site study was carried out shortly after the event. In addition, a WorldView-1 panchromatic satellite image was obtained to map the non-accessible parts of the avalanche. Here, we present findings from the field visit, from image analyses and first modellings of the avalanche run-out.
format Article in Journal/Newspaper
author Frauenfelder, Regula
Jónsson, Árni
Lied, Karstein
Schwerdtfeger, Dirk
Bergum, Guro
Bühler, Yves
Stoffe, Lukas
author_facet Frauenfelder, Regula
Jónsson, Árni
Lied, Karstein
Schwerdtfeger, Dirk
Bergum, Guro
Bühler, Yves
Stoffe, Lukas
author_sort Frauenfelder, Regula
title Analysis of an artificially triggered avalanche at the nepheline syenite mine on Stjernøya, Alta, Northern Norway
title_short Analysis of an artificially triggered avalanche at the nepheline syenite mine on Stjernøya, Alta, Northern Norway
title_full Analysis of an artificially triggered avalanche at the nepheline syenite mine on Stjernøya, Alta, Northern Norway
title_fullStr Analysis of an artificially triggered avalanche at the nepheline syenite mine on Stjernøya, Alta, Northern Norway
title_full_unstemmed Analysis of an artificially triggered avalanche at the nepheline syenite mine on Stjernøya, Alta, Northern Norway
title_sort analysis of an artificially triggered avalanche at the nepheline syenite mine on stjernøya, alta, northern norway
publisher Montana State University Library
publishDate 2014
url https://hdl.handle.net/11250/3083292
https://arc.lib.montana.edu/snow-science/item/2134
long_lat ENVELOPE(22.107,22.107,70.257,70.257)
ENVELOPE(22.597,22.597,70.273,70.273)
ENVELOPE(16.415,16.415,76.536,76.536)
geographic Alta
Lillebukt
Nabbaren
Norway
Stjernøya
geographic_facet Alta
Lillebukt
Nabbaren
Norway
Stjernøya
genre Northern Norway
Stjernøya
genre_facet Northern Norway
Stjernøya
op_source 8
op_relation The International Snow Science Workshop (ISSW) Proceedings;
https://hdl.handle.net/11250/3083292
https://arc.lib.montana.edu/snow-science/item/2134
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