Effects of sediment instabilities on benthic microhabitats : case of Kongsfjorden
Sediment depositional events often occur in coastal areas and have major consequences on benthic ecosystems and biogeochemistry. In the Arctic, fjords are transitional environments subjected to glacier melting and large sedimentary inputs. In a context of current climate change, projections predict...
Main Author: | |
---|---|
Other Authors: | , , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | French |
Published: |
HAL CCSD
2023
|
Subjects: | |
Online Access: | https://theses.hal.science/tel-04584565 https://theses.hal.science/tel-04584565/document https://theses.hal.science/tel-04584565/file/GUILHERMIC.pdf |
id |
ftinsu:oai:HAL:tel-04584565v1 |
---|---|
record_format |
openpolar |
spelling |
ftinsu:oai:HAL:tel-04584565v1 2024-06-23T07:50:50+00:00 Effects of sediment instabilities on benthic microhabitats : case of Kongsfjorden Effets des instabilités sédimentaires sur les microhabitats benthiques : cas du Kongsfjorden Guilhermic, Corentin Laboratoire de Planétologie et Géodynamique UMR 6112 (LPG) Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST) Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Université d'Angers Hélène Howa Maria-Pia Nardelli Aurélia Mouret 2023-12-15 https://theses.hal.science/tel-04584565 https://theses.hal.science/tel-04584565/document https://theses.hal.science/tel-04584565/file/GUILHERMIC.pdf fr fre HAL CCSD NNT: 2023ANGE0068 tel-04584565 https://theses.hal.science/tel-04584565 https://theses.hal.science/tel-04584565/document https://theses.hal.science/tel-04584565/file/GUILHERMIC.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-04584565 Sciences de la Terre. Université d'Angers, 2023. Français. ⟨NNT : 2023ANGE0068⟩ Glacier Svalbard Foraminifera Biogeochemistry Disturbance Experiment Perturbation [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/doctoralThesis Theses 2023 ftinsu 2024-05-29T23:54:24Z Sediment depositional events often occur in coastal areas and have major consequences on benthic ecosystems and biogeochemistry. In the Arctic, fjords are transitional environments subjected to glacier melting and large sedimentary inputs. In a context of current climate change, projections predict an increase of this melting in the future. In Kongsfjorden (Svalbard), a gradient of turbidity highly affects primary production, benthic faunas and microhabitat stability. In order to understand the effects of these environmental gradients in this fjord on the benthic compartment, this Ph.D. proposes an experimental/environmental approach allowing to assess the recovery processes of benthic foraminifera communities and redox gradients after sediment disturbances. Experimentally highlighted burial markers allowed us to observe the effects of this strong summer sedimentation in the fjord which can be seen both in recovery states of early diagenesis processes and seasonal benthic foraminiferal community biozonations on a kilometric scale. Foraminiferal distributionand sediment redox states were proven to be relevant indicators to survey interannual effects of glacier melting on benthic microhabitats Des évènements de dépôts sédimentaires surviennent dans les zones côtières et ont des conséquences majeures sur les écosystèmes benthiques. En Arctique, les fjords sont des environnements soumis à la fonte des glaciers et à d'importants apports sédimentaires. Avec le changement climatique actuel, les projections prévoient une augmentation de cette fonte dans le futur. Dans le Kongsfjord (Svalbard), cette décharge sédimentaire affecte fortement la productivité primaire, les faunes benthiques et la stabilité des microhabitats. Pour comprendre les effets de ces gradients environnementaux sur le compartiment benthique, cette thèse propose une approche couplant des études expérimentales et environnementales permettant de comprendre les processus de rétablissement des communautés de foraminifères benthiques et des gradients ... Doctoral or Postdoctoral Thesis Arctic Arctique* Climate change Foraminifera* glacier Kongsfjord* Kongsfjorden Svalbard Institut national des sciences de l'Univers: HAL-INSU Arctic Kongsfjord ENVELOPE(29.319,29.319,70.721,70.721) Svalbard |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
French |
topic |
Glacier Svalbard Foraminifera Biogeochemistry Disturbance Experiment Perturbation [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
Glacier Svalbard Foraminifera Biogeochemistry Disturbance Experiment Perturbation [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Guilhermic, Corentin Effects of sediment instabilities on benthic microhabitats : case of Kongsfjorden |
topic_facet |
Glacier Svalbard Foraminifera Biogeochemistry Disturbance Experiment Perturbation [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
Sediment depositional events often occur in coastal areas and have major consequences on benthic ecosystems and biogeochemistry. In the Arctic, fjords are transitional environments subjected to glacier melting and large sedimentary inputs. In a context of current climate change, projections predict an increase of this melting in the future. In Kongsfjorden (Svalbard), a gradient of turbidity highly affects primary production, benthic faunas and microhabitat stability. In order to understand the effects of these environmental gradients in this fjord on the benthic compartment, this Ph.D. proposes an experimental/environmental approach allowing to assess the recovery processes of benthic foraminifera communities and redox gradients after sediment disturbances. Experimentally highlighted burial markers allowed us to observe the effects of this strong summer sedimentation in the fjord which can be seen both in recovery states of early diagenesis processes and seasonal benthic foraminiferal community biozonations on a kilometric scale. Foraminiferal distributionand sediment redox states were proven to be relevant indicators to survey interannual effects of glacier melting on benthic microhabitats Des évènements de dépôts sédimentaires surviennent dans les zones côtières et ont des conséquences majeures sur les écosystèmes benthiques. En Arctique, les fjords sont des environnements soumis à la fonte des glaciers et à d'importants apports sédimentaires. Avec le changement climatique actuel, les projections prévoient une augmentation de cette fonte dans le futur. Dans le Kongsfjord (Svalbard), cette décharge sédimentaire affecte fortement la productivité primaire, les faunes benthiques et la stabilité des microhabitats. Pour comprendre les effets de ces gradients environnementaux sur le compartiment benthique, cette thèse propose une approche couplant des études expérimentales et environnementales permettant de comprendre les processus de rétablissement des communautés de foraminifères benthiques et des gradients ... |
author2 |
Laboratoire de Planétologie et Géodynamique UMR 6112 (LPG) Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST) Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Université d'Angers Hélène Howa Maria-Pia Nardelli Aurélia Mouret |
format |
Doctoral or Postdoctoral Thesis |
author |
Guilhermic, Corentin |
author_facet |
Guilhermic, Corentin |
author_sort |
Guilhermic, Corentin |
title |
Effects of sediment instabilities on benthic microhabitats : case of Kongsfjorden |
title_short |
Effects of sediment instabilities on benthic microhabitats : case of Kongsfjorden |
title_full |
Effects of sediment instabilities on benthic microhabitats : case of Kongsfjorden |
title_fullStr |
Effects of sediment instabilities on benthic microhabitats : case of Kongsfjorden |
title_full_unstemmed |
Effects of sediment instabilities on benthic microhabitats : case of Kongsfjorden |
title_sort |
effects of sediment instabilities on benthic microhabitats : case of kongsfjorden |
publisher |
HAL CCSD |
publishDate |
2023 |
url |
https://theses.hal.science/tel-04584565 https://theses.hal.science/tel-04584565/document https://theses.hal.science/tel-04584565/file/GUILHERMIC.pdf |
long_lat |
ENVELOPE(29.319,29.319,70.721,70.721) |
geographic |
Arctic Kongsfjord Svalbard |
geographic_facet |
Arctic Kongsfjord Svalbard |
genre |
Arctic Arctique* Climate change Foraminifera* glacier Kongsfjord* Kongsfjorden Svalbard |
genre_facet |
Arctic Arctique* Climate change Foraminifera* glacier Kongsfjord* Kongsfjorden Svalbard |
op_source |
https://theses.hal.science/tel-04584565 Sciences de la Terre. Université d'Angers, 2023. Français. ⟨NNT : 2023ANGE0068⟩ |
op_relation |
NNT: 2023ANGE0068 tel-04584565 https://theses.hal.science/tel-04584565 https://theses.hal.science/tel-04584565/document https://theses.hal.science/tel-04584565/file/GUILHERMIC.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1802641780162691072 |