scholarly journals Small rock-slope failures conditioned by Holocene permafrost degradation: a new approach and conceptual model based on Schmidt-hammer exposure-age dating, Jotunheimen, southern Norway

Boreas ◽  
2018 ◽  
Vol 47 (4) ◽  
pp. 1144-1169 ◽  
Author(s):  
John A. Matthews ◽  
Stefan Winkler ◽  
Peter Wilson ◽  
Matt D. Tomkins ◽  
Jason M. Dortch ◽  
...  
Keyword(s):  
Conceptual Model ◽  
Rock Slope ◽  
Age Dating ◽  
Permafrost Degradation ◽  
Schmidt Hammer ◽  
Slope Failures ◽  
New Approach ◽  
Model Based ◽  
Exposure Age ◽  
Southern Norway

scholarly journals Snow-avalanche boulder fans in Jotunheimen, southern Norway: Schmidt-hammer exposure-age dating, geomorphometrics, dynamics and evolution

2020 ◽  
Vol 102 (2) ◽  
pp. 118-140
Author(s):  
John A. Matthews ◽  
Stefan Haselberger ◽  
Jennifer L. Hill ◽  
Geraint Owen ◽  
Stefan Winkler ◽  
...  
Keyword(s):  
Age Dating ◽  
Snow Avalanche ◽  
Schmidt Hammer ◽  
Exposure Age ◽  
Southern Norway

Holocene alluvial fan evolution, Schmidt‐hammer exposure‐age dating and paraglacial debris floods in the SE Jostedalsbreen region, southern Norway

Boreas ◽  
2020 ◽  
Vol 49 (4) ◽  
pp. 886-902
Author(s):  
John A. Matthews ◽  
Lindsey J. McEwen ◽  
Geraint Owen ◽  
Sietse Los
Keyword(s):  
Alluvial Fan ◽  
Age Dating ◽  
Schmidt Hammer ◽  
Exposure Age ◽  
Southern Norway ◽  
Debris Floods

scholarly journals Age and development of active cryoplanation terraces in the alpine permafrost zone at Svartkampan, Jotunheimen, southern Norway

2019 ◽  
Vol 92 (3) ◽  
pp. 641-664 ◽  
Author(s):  
John A. Matthews ◽  
Peter Wilson ◽  
Stefan Winkler ◽  
Richard W. Mourne ◽  
Jennifer L. Hill ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Groundwater Flow ◽  
Age Dating ◽  
Schmidt Hammer ◽  
Radiocarbon Dates ◽  
Exposure Age ◽  
Frost Penetration ◽  
Southern Norway ◽  
The Last Glacial Maximum ◽  
The Last Glacial

AbstractSchmidt-hammer exposure-age dating (SHD) of boulders on cryoplanation terrace treads and associated bedrock cliff faces revealed Holocene ages ranging from 0 ± 825 to 8890 ± 1185 yr. The cliffs were significantly younger than the inner treads, which tended to be younger than the outer treads. Radiocarbon dates from the regolith of 3854 to 4821 cal yr BP (2σ range) indicated maximum rates of cliff recession of ~0.1 mm/yr, which suggests the onset of terrace formation before the last glacial maximum. Age, angularity, and size of clasts, together with planation across bedrock structures and the seepage of groundwater from the cliff foot, all support a process-based conceptual model of cryoplanation terrace development in which frost weathering leads to parallel cliff recession and, hence, terrace extension. The availability of groundwater during autumn freezeback is viewed as critical for frost wedging and/or the growth of segregation ice during prolonged winter frost penetration. Permafrost promotes cryoplanation by providing an impermeable frost table beneath the active layer, focusing groundwater flow, and supplying water for sediment transport by solifluction across the tread. Snow beds are considered an effect rather than a cause of cryoplanation terraces, and cryoplanation is seen as distinct from nivation.

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