La caldera du Torfajökull et sa diversité géomorphologique (Islande)

The outstanding geomorphological diversity of the Torfajökull caldera is the result of the activity of several processes : volcanism, geothermy, gelifraction, glacial erosion and fluvial erosion, as well as the combination of several of these processes. The rhyolite outcrops and their erosion into a...

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Bibliographic Details
Published in:Dynamiques environnementales
Main Author: Bussard, Jonathan
Format: Article in Journal/Newspaper
Language:French
Published: Presses universitaires de Bordeaux 2022
Subjects:
geo
Online Access:http://journals.openedition.org/dynenviron/4679
Description
Summary:The outstanding geomorphological diversity of the Torfajökull caldera is the result of the activity of several processes : volcanism, geothermy, gelifraction, glacial erosion and fluvial erosion, as well as the combination of several of these processes. The rhyolite outcrops and their erosion into a vast, light-coloured sandur contrast with the black obsidian lava flow, the Laugahraun, which dates from 1477. In order to protect the geothermal forms, the caldera has been protected since 1979, but the recent increase in tourist numbers is increasing the human pressure on these fragile sites. La diversité géomorphologique exceptionnelle de la caldera du Torfajökull est le résultat de l’activité de plusieurs processus : le volcanisme, la géothermie, la gélifraction, l’érosion glaciaire et l’érosion fluviale, ainsi que la combinaison entre plusieurs de ces processus. Les affleurements de rhyolites et leur érosion venant alimenter un vaste sandur aux couleurs claires contrastent avec la coulée de lave noire d’obsidienne, la Laugahraun, qui date de l’an 1477. Afin de protéger les formes géothermales, la caldera est protégée depuis 1979, mais la récente augmentation de la fréquentation touristique accentue la pression humaine sur ces sites fragiles.