Late Holocene Changes in Erosion Patterns in a Lacustrine Environment: Landscape Stabilization by Volcanic Activity Versus Human Activity
| Autor: | Sabine Schmidt, Osamu Fujiwara, Jacqueline Vander Auwera, Aurélia Hubert-Ferrari, Yusuke Yokoyama, Gilles Lepoint, Marc De Batist, Shinya Yamamoto, Evelien Boes, Meriam El Ouahabi, Laura Lamair, Vanessa M.A. Heyvaert |
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| Přispěvatelé: | Department of Geography, University of Liège, Clos Mercator 3, 4000 Liège, Belgium, Université de Liège, Graduate School of Information Systems, University of Electro-Communications [Tokyo] (UEC), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), L.A. Géologie, Pétrologie et Géochimie, MARE Centre, Laboratory for Oceanology, Atmosphere and Ocean Research Institute [Kashiwa-shi] (AORI), The University of Tokyo (UTokyo), Renard Centre of Marine Geology, RCMG |
| Rok vydání: | 2019 |
| Předmět: |
geography
geography.geographical_feature_category Vulcanian eruption 010504 meteorology & atmospheric sciences Geochemistry Sediment 15. Life on land Sedimentation 010502 geochemistry & geophysics 01 natural sciences Geophysics Volcano 13. Climate action Geochemistry and Petrology Erosion Scoria [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment Tephra ComputingMilieux_MISCELLANEOUS Holocene Geology 0105 earth and related environmental sciences |
| Zdroj: | Geochemistry, Geophysics, Geosystems Geochemistry, Geophysics, Geosystems, AGU and the Geochemical Society, 2019, ⟨10.1029/2018GC008067⟩ |
| ISSN: | 1525-2027 |
| Popis: | The most recent eruption of Mount Fuji (Japan), the VEI 5 Hoei plinian eruption (CE 1707) heavily impacted Lake Yamanaka, a shallow lake located at the foot of Mount Fuji. Here we discuss the influence of the Hoei eruption on the lacustrine sedimentation of Lake Yamanaka using high-resolution geophysical and geochemical measurements on gravity cores. Hoei scoria fallout had two major impacts on Lake Yamanaka: (i) reduction of the sedimentation rate (from similar to 0.16 to similar to 0.09 cm/year) and (ii) the increase of in situ lake productivity. Sedimentation rates after the eruption were relatively low due to the thick scoria layer, trapping underlying sediments in the catchment. The lacustrine system took more than similar to 170 years to begin to recover from the Hoei eruption: most recently sedimentation recovery has been accelerated by changes in land use. Since the beginning of the twentieth century, vegetated strips delimited cultivated parcels, trapping sediment and minimizing anthropogenic impacts on the sedimentation rate. Over the last decade, the decline of agriculture and the increase of other human activities has led to an increase in the sedimentation rate (similar to 1 cm/year). This study highlights the effect of the grainsize of the volcanic ejecta on the sedimentation rate following a volcanic eruption. Coarse-grained tephra are difficult to erode. Therefore, their erosion and remobilization is largely limited to intense typhoons when porous scoria deposits are saturated by heavy rains. Moreover, this study suggests that recent anthropogenic modifications of the catchment had a greater impact on the sedimentation rate than the Hoei eruption. |
| Databáze: | OpenAIRE |
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