Denudation rates during a postglacial sequence in Northern Iceland: example of Laxárdalur valley in the Skagafjörður area
Etienne Cossart
(1, 2)
,
Denis Mercier
(3, 4)
,
Julien Coquin
(5)
,
Armelle Decaulne
(6)
,
Thierry Feuillet
(7, 8)
,
Helgi Páll Jónsson
,
Þorsteinn Sæmundsson
1
EVS -
Environnement, Ville, Société
2 UJML - Université Jean Moulin - Lyon 3
3 ENeC - Espaces, Nature et Culture
4 UP4 - Université Paris-Sorbonne
5 LETG - Nantes - Littoral, Environnement, Télédétection, Géomatique
6 LETG - Littoral, Environnement, Télédétection, Géomatique UMR 6554
7 LADYSS - Laboratoire Dynamiques Sociales et Recomposition des Espaces
8 UP8 - Université Paris 8 Vincennes-Saint-Denis
2 UJML - Université Jean Moulin - Lyon 3
3 ENeC - Espaces, Nature et Culture
4 UP4 - Université Paris-Sorbonne
5 LETG - Nantes - Littoral, Environnement, Télédétection, Géomatique
6 LETG - Littoral, Environnement, Télédétection, Géomatique UMR 6554
7 LADYSS - Laboratoire Dynamiques Sociales et Recomposition des Espaces
8 UP8 - Université Paris 8 Vincennes-Saint-Denis
Etienne Cossart
- Fonction : Auteur
- PersonId : 981905
- ORCID : 0000-0001-7457-542X
- IdRef : 096289449
Denis Mercier
- Fonction : Auteur
- PersonId : 8684
- IdHAL : dmercier
- ORCID : 0000-0003-2325-1390
- IdRef : 059339322
Julien Coquin
- Fonction : Auteur
- PersonId : 7560
- IdHAL : julien-coquin
- IdRef : 192425641
Armelle Decaulne
- Fonction : Auteur
- PersonId : 179996
- IdHAL : armelle-decaulne
- ORCID : 0000-0002-8029-850X
Thierry Feuillet
- Fonction : Auteur
- PersonId : 744616
- IdHAL : thierry-feuillet
- ORCID : 0000-0002-5494-538X
- IdRef : 153040610
Helgi Páll Jónsson
- Fonction : Auteur
Þorsteinn Sæmundsson
- Fonction : Auteur
Résumé
For several decades, geomorphologists have focused on the functioning of geomorphic systems after deglaciation. The relative importance of paraglacial vs. periglacial processes has been highly debated. At present, the development of dating techniques allows to contribute to this debate. We reconstruct in this paper the geomorphic evolution of Tindastóll mountain slopes in Laxárdalur valley (Skagafjörður area, central northern Iceland), where a chronological framework can be established through tephrochronology and an assemblage of dated raised beaches. Volumetric calculations of constructed and excavated landforms were created from field data and from DEM and geographical information system techniques. Collectively, our data exhibit a first stage of paraglacial landsliding during the first half of the Holocene, followed by a stage of scree and rockglacier development (during the second half of the Holocene, but before 1100 AD). Our estimations indicate that more than 85% of the total sediment production were due to rock slope failure, and the rate of bedrock denudation due to periglacial processes was about one half of the rate of paraglacial processes. Nevertheless, paraglacial and periglacial processes cannot be seen here as antagonistic processes: they are organized in a sequence during which periglacial processes are conditioned (enhancement of bedrock denudation rates) by fracturing and consequent mass wasting. Screes and concomitant rockglaciers were indeed preconditioned by the landslide, while areas non-affected by landslides have remained mostly intact, characterized by a very low rate of accumulation due to geomorphic (periglacial) activity.
Domaines
GéographieFormat du dépôt | Notice |
---|---|
Type de dépôt | Article dans une revue |
Résumé |
en
For several decades, geomorphologists have focused on the functioning of geomorphic systems after deglaciation. The relative importance of paraglacial vs. periglacial processes has been highly debated. At present, the development of dating techniques allows to contribute to this debate. We reconstruct in this paper the geomorphic evolution of Tindastóll mountain slopes in Laxárdalur valley (Skagafjörður area, central northern Iceland), where a chronological framework can be established through tephrochronology and an assemblage of dated raised beaches. Volumetric calculations of constructed and excavated landforms were created from field data and from DEM and geographical information system techniques. Collectively, our data exhibit a first stage of paraglacial landsliding during the first half of the Holocene, followed by a stage of scree and rockglacier development (during the second half of the Holocene, but before 1100 AD). Our estimations indicate that more than 85% of the total sediment production were due to rock slope failure, and the rate of bedrock denudation due to periglacial processes was about one half of the rate of paraglacial processes. Nevertheless, paraglacial and periglacial processes cannot be seen here as antagonistic processes: they are organized in a sequence during which periglacial processes are conditioned (enhancement of bedrock denudation rates) by fracturing and consequent mass wasting. Screes and concomitant rockglaciers were indeed preconditioned by the landslide, while areas non-affected by landslides have remained mostly intact, characterized by a very low rate of accumulation due to geomorphic (periglacial) activity.
|
Titre |
en
Denudation rates during a postglacial sequence in Northern Iceland: example of Laxárdalur valley in the Skagafjörður area
|
Auteur(s) |
Etienne Cossart
1, 2
, Denis Mercier
3, 4
, Julien Coquin
5
, Armelle Decaulne
6
, Thierry Feuillet
7, 8
, Helgi Páll Jónsson
, Þorsteinn Sæmundsson
1
EVS -
Environnement, Ville, Société
( 145345 )
- 18 Rue Chevreul
69362 LYON CEDEX 07
UMR 5600
- France
2
UJML -
Université Jean Moulin - Lyon 3
( 118744 )
- 6 cours Albert Thomas - 69008 Lyon
- France
3
ENeC -
Espaces, Nature et Culture
( 224523 )
- Laboratoire Espaces, Nature et Culture (ENeC)
UMR CNRS-Paris IV 8185
Maison de la Recherche
28 rue Serpente
75006 Paris
- France
4
UP4 -
Université Paris-Sorbonne
( 123821 )
- 1 rue Victor Cousin - 75005 Paris
- France
5
LETG - Nantes -
Littoral, Environnement, Télédétection, Géomatique
( 2267 )
- Institut de Géographie et d'Aménagement de l'Université de Nantes Campus du Tertre BP 8122
44312 NANTES CEDEX 3
- France
6
LETG -
Littoral, Environnement, Télédétection, Géomatique UMR 6554
( 14266 )
- Institut Universitaire Européen de la Mer - Technopôle Brest-Iroise - Place Nicolas Copernic 29280 Plouzané
- France
7
LADYSS -
Laboratoire Dynamiques Sociales et Recomposition des Espaces
( 1096 )
- Université Paris Ouest Nanterre La Défense Bâtiment T 200 avenue de la République 92001 Nanterre cedex
- France
8
UP8 -
Université Paris 8 Vincennes-Saint-Denis
( 11141 )
- 2 rue de la Liberté - 93526 Saint-Denis cedex
- France
|
Page/Identifiant |
240-261
|
Langue du document |
Anglais
|
Date de production/écriture |
2016-04
|
Nom de la revue |
|
Vulgarisation |
Non
|
Comité de lecture |
Oui
|
Audience |
Internationale
|
Date de publication |
2017-05-03
|
Date de publication électronique |
2017-05-03
|
Volume |
99
|
Numéro |
3
|
Financement |
|
Domaine(s) |
|
Mots-clés |
en
Rockglacier, Landslide, Denudation rates, Slope, Paraglacial, Periglacial, Holocene
|
DOI | 10.1080/04353676.2017.1327320 |
Loading...