The extreme yet transient nature of glacial erosion
|Author:||Patton, H.1; Hubbard, A.1,2; Heyman, J.3;|
1CAGE – Centre for Arctic Gas Hydrate, Environment, and Climate, Department of Geosciences, UiT The Arctic University of Norway, Tromsø, Norway
2Geography Research Unit, University of Oulu, Oulu, Finland
3Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
4ARCEx – Research Centre for Arctic Petroleum Exploration, Department of Geosciences, UiT The Arctic University of Norway, Tromsø, Norway
5Department of Earth Sciences, Royal Holloway University of London, Egham, UK
6Geomorphology and Glaciology, Department of Physical Geography, Stockholm University, Stockholm, Sweden
7Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
8School of Geosciences, University of Edinburgh, Edinburgh, UK
|Online Access:||PDF Full Text (PDF, 29 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2023060252008
|Publish Date:|| 2023-06-02
Ice can sculpt extraordinary landscapes, yet the efficacy of, and controls governing, glacial erosion on geological timescales remain poorly understood and contended, particularly across Polar continental shields. Here, we assimilate geophysical data with modelling of the Eurasian Ice Sheet — the third largest Quaternary ice mass that spanned 49°N to 82°N — to decipher its erosional footprint during the entire last ~100 ka glacial cycle. Our results demonstrate extreme spatial and temporal heterogeneity in subglacial erosion, with rates ranging from 0 to 5 mm a−1 and a net volume equating to ~130,000 km3 of bedrock excavated to depths of ~190 m. A hierarchy of environmental controls ostensibly underpins this complex signature: lithology, topography and climate, though it is basal thermodynamics that ultimately regulates erosion, which can be variously protective, pervasive, or, highly selective. Our analysis highlights the remarkable yet fickle nature of glacial erosion — critically modulated by transient ice-sheet dynamics — with its capacity to impart a profound but piecemeal geological legacy across mid- and high latitudes.
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
This research is a part of the Centre for Arctic Gas Hydrate, Environment, and Climate and was supported by the Research Council of Norway through its Centre of Excellence funding scheme (grant 223259) and the Akademia Programme at Equinor. Ice modelling experiments were performed using High-Performance Computing services through Sigma2 (project #NN9465K). AH gratefully acknowledges an Arctic Interactions fellowship at the University of Oulu funded by the Finnish Academy of Sciences and an Arctic Five Professorship. Open access funding provided by UiT The Arctic University of Norway (incl University Hospital of North Norway).
The bedrock 10Be cosmogenic data analyzed and used for calibration of the ice sheet / glacial erosion model is provided in Supplementary Data 1. Raw data are derived from the expage compilation of glacial 10Be and 26Al data (http://expage.github.io/).
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