Using geophysics on a terminal moraine damming a glacial lake: the Flatbre debris flow case, Western Norway
International audience A debris flow occurred on 8 May 2004, in Fj?rland, Western Norway, due to a Glacial Lake Outburst Flood and a natural terminal moraine failure. The site was investigated in 2004 and 2005, using pre- and post-flow aerial photos, airborne laser scanning, and extensive field work...
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ftinsu:oai:HAL:hal-00328615v1 2023-11-12T04:18:37+01:00 Using geophysics on a terminal moraine damming a glacial lake: the Flatbre debris flow case, Western Norway Lecomte, I. Thollet, I. Juliussen, H. Hamran, S.-E. International Centre for Geohazards P.O.Box 3930 NORSAR Norwegian Seismic Array (NORSAR) Ecole et Observatoire des Sciences de la Terre (EOST) Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) University of Oslo (UiO) 2008-04-24 https://hal.science/hal-00328615 https://hal.science/hal-00328615/document https://hal.science/hal-00328615/file/adgeo-14-301-2008.pdf en eng HAL CCSD European Geosciences Union hal-00328615 https://hal.science/hal-00328615 https://hal.science/hal-00328615/document https://hal.science/hal-00328615/file/adgeo-14-301-2008.pdf info:eu-repo/semantics/OpenAccess ISSN: 1680-7340 EISSN: 1680-7359 Advances in Geosciences https://hal.science/hal-00328615 Advances in Geosciences, 2008, 14, pp.307 [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2008 ftinsu 2023-10-25T16:24:35Z International audience A debris flow occurred on 8 May 2004, in Fj?rland, Western Norway, due to a Glacial Lake Outburst Flood and a natural terminal moraine failure. The site was investigated in 2004 and 2005, using pre- and post-flow aerial photos, airborne laser scanning, and extensive field work investigations, resulting in a good understanding of the mechanics of the debris flow, with quantification of the entrainment and determination of the final volume involved. However, though the moraine had a clear weak point, with lower elevation and erosion due to overflowing in the melting season, the sudden rupture of the moraine still needs to be explained. As moraines often contain an ice core, a possible cause could be the melting of the ice, inducing a progressive weakening of the structure. Geophysical investigations were therefore carried out in September 2006, including seismic refraction, GPR and resistivity. All methods worked well, but none revealed the presence of ice, though the depth to bedrock was determined. On the contrary, the moraine appeared to be highly saturated in water, especially in one area, away from the actual breach and corresponding to observed water seepage at the foot of the moraine. To estimate future hazard, water circulation through the moraine should be monitored over time. Article in Journal/Newspaper ice core Institut national des sciences de l'Univers: HAL-INSU Glacial Lake ENVELOPE(-129.463,-129.463,58.259,58.259) Norway |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences Lecomte, I. Thollet, I. Juliussen, H. Hamran, S.-E. Using geophysics on a terminal moraine damming a glacial lake: the Flatbre debris flow case, Western Norway |
topic_facet |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience A debris flow occurred on 8 May 2004, in Fj?rland, Western Norway, due to a Glacial Lake Outburst Flood and a natural terminal moraine failure. The site was investigated in 2004 and 2005, using pre- and post-flow aerial photos, airborne laser scanning, and extensive field work investigations, resulting in a good understanding of the mechanics of the debris flow, with quantification of the entrainment and determination of the final volume involved. However, though the moraine had a clear weak point, with lower elevation and erosion due to overflowing in the melting season, the sudden rupture of the moraine still needs to be explained. As moraines often contain an ice core, a possible cause could be the melting of the ice, inducing a progressive weakening of the structure. Geophysical investigations were therefore carried out in September 2006, including seismic refraction, GPR and resistivity. All methods worked well, but none revealed the presence of ice, though the depth to bedrock was determined. On the contrary, the moraine appeared to be highly saturated in water, especially in one area, away from the actual breach and corresponding to observed water seepage at the foot of the moraine. To estimate future hazard, water circulation through the moraine should be monitored over time. |
author2 |
International Centre for Geohazards P.O.Box 3930 NORSAR Norwegian Seismic Array (NORSAR) Ecole et Observatoire des Sciences de la Terre (EOST) Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) University of Oslo (UiO) |
format |
Article in Journal/Newspaper |
author |
Lecomte, I. Thollet, I. Juliussen, H. Hamran, S.-E. |
author_facet |
Lecomte, I. Thollet, I. Juliussen, H. Hamran, S.-E. |
author_sort |
Lecomte, I. |
title |
Using geophysics on a terminal moraine damming a glacial lake: the Flatbre debris flow case, Western Norway |
title_short |
Using geophysics on a terminal moraine damming a glacial lake: the Flatbre debris flow case, Western Norway |
title_full |
Using geophysics on a terminal moraine damming a glacial lake: the Flatbre debris flow case, Western Norway |
title_fullStr |
Using geophysics on a terminal moraine damming a glacial lake: the Flatbre debris flow case, Western Norway |
title_full_unstemmed |
Using geophysics on a terminal moraine damming a glacial lake: the Flatbre debris flow case, Western Norway |
title_sort |
using geophysics on a terminal moraine damming a glacial lake: the flatbre debris flow case, western norway |
publisher |
HAL CCSD |
publishDate |
2008 |
url |
https://hal.science/hal-00328615 https://hal.science/hal-00328615/document https://hal.science/hal-00328615/file/adgeo-14-301-2008.pdf |
long_lat |
ENVELOPE(-129.463,-129.463,58.259,58.259) |
geographic |
Glacial Lake Norway |
geographic_facet |
Glacial Lake Norway |
genre |
ice core |
genre_facet |
ice core |
op_source |
ISSN: 1680-7340 EISSN: 1680-7359 Advances in Geosciences https://hal.science/hal-00328615 Advances in Geosciences, 2008, 14, pp.307 |
op_relation |
hal-00328615 https://hal.science/hal-00328615 https://hal.science/hal-00328615/document https://hal.science/hal-00328615/file/adgeo-14-301-2008.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782335226535477248 |