Schmidt-hammer exposure-age dating (SHD) of snow-avalanche impact ramparts in southern Norway: Approaches, results and implications for landform age, dynamics and development

Mcewen, Lindsey J.; Matthews, John A.; McEwen, Lindsey; Owen, Geraint

Abstract

© 2015 John Wiley & Sons, Ltd. Schmidt-hammer exposure-age dating (SHD) was applied to the problem of dating the diachronous surfaces of five distal river-bank boulder ramparts deposited by snow avalanches plunging into the Jostedøla and Sprongdøla rivers in the Jostedalsbreen region of southern Norway. Approaches to local high-precision linear age calibration, which controlled in different ways for boulder roundness, were developed. The mean age (SHDmean) and the maximum age (SHDmax) of surface boulders were estimated for whole ramparts, crests and distal fringes. Interpretation was further assisted by reference to R-value distributions. SHDmean ages (with 95% confidence intervals) ranged from 520±270years to 5375±965years, whereas SHDmax ages (expected to be exceeded by

• Journal Article Type: Article
• Acceptance Date: Jan 31, 2015
• Publication Date: Oct 1, 2015
• Journal: Earth Surface Processes and Landforms
• Print ISSN: 0197-9337
• Electronic ISSN: 1096-9837
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 40
• Issue: 13
• Pages: 1705-1718
• DOI: https://doi.org/10.1002/esp.3746
• Keywords: snow-avalanche impact landforms and deposits, Schmidt-hammer exposure-age dating (SHD), holocene landform development, avalanche frequency, river bedload, Jostedalsbreen region, Norway
• Public URL: https://uwe-repository.worktribe.com/output/843227
• Publisher URL: http://dx.doi.org/10.1002/esp.3746