RT Journal Article
T1 Origins of the divergent evolution of mountain glaciers during deglaciation: Hofsdalur cirques, Northern Iceland
A1 Tanarro García, Luis Miguel
A1 Palacios Estremera, David
A1 Fernández Fernández, José M.
A1 Andrés de Pablo, Nuria de
A1 Oliva, Marc
A1 Rodríguez Mena, Manuel
A1 Schimmelpfennig, Irene
A1 Brynjólfsson, Skafti
A1 Sæmundsson, þorsteinn
A1 Zamorano, José J.
A1 Ubeda Palenque, José
A1 Aumaître, Georges
A1 Bourlès, Didier
A1 Keddadouche, Karim
AB The aim of this work is to study the process of transformation of debris-free mountain glaciers into debris-covered glaciers and rock glaciers, and to examine the factors driving diverging evolution in similar glacial systems. The study area is the Hofsdalur valley, in the Trollaskagi peninsula (northern € Iceland), where several cirques host a great diversity of glaciers and rock glaciers as well as various glacial landforms. Four adjacent cirques have been analysed through a multidisciplinary approach: geomorphological analysis, boulder surface displacement tracking, quantification of recent glacier changes, three dimensional palaeoglacier reconstruction, equilibrium-line altitude calculations and relative and direct dating methods applied to surface boulders. Dating methods included in situ 36Cl cosmic-ray exposure dating, Schmidt hammer weathering measurements and lichenometric dating. The results confirm that glaciers in Hofsdalur followed an evolution pattern similar to that observed in other cirques in the Trollaskagi peninsula. During the Younger Dryas (12.9 € e11.7 ka) many of those cirques hosted debris-free glaciers, whose retreat started in the early Holocene. Distinct retreat dynamics and cirque floor elevation conditioned the subsequent glacial evolution. In some Trollaskagi cirques, the ice € completely covered the headwalls, which consequently did not supply debris onto the glacier surface, which remained debris-free. In most of these cirques, however, glacier retreat enhanced paraglacial processes and the ice-free cirque walls generated a high debris supply onto the glacier surface. As a result, the glaciers evolved towards debris-covered glaciers or rock glaciers, depending on the local topographical setting. In the lower cirques they collapsed immediately after their formation. At higher altitudes, above the lower permafrost limit, these ice-cored landforms have survived until the present day, but they have been stagnant since the Holocene Thermal Maximum, while the heads of these cirques have hosted debris-free glaciers during the Late Holocene.
PB Elsevier
SN 0277-3791
YR 2021
FD 2021-11-02
LK https://hdl.handle.net/20.500.14352/4624
UL https://hdl.handle.net/20.500.14352/4624
LA eng
NO CRUE-CSIC (Acuerdos Transformativos 2021)
NO Ministerio de Ciencia e Innovación (MICINN)
NO Universidad Complutense de Madrid/Banco de Santander
NO Fundaçao para a Ciencia e a Tecnologia, Portugal
NO Generalitat de Catalunya
DS Docta Complutense
RD 2 may 2024