EGU21-1539, updated on 03 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Recent, rapid and profound changes to glacier morphology and dynamics, Juneau Icefield, Alaska

Bethan Davies1, Jacob Bendle2, Robert McNabb3, Jonathan Carrivick4, Christopher McNeil5, Seth Campbell6, and Mauri Pelto7
Bethan Davies et al.
  • 1Royal Holloway University of London, Geography, Egham, United Kingdom of Great Britain – England, Scotland, Wales (
  • 22. Natural Resources and Environmental Studies Institute, Geography Program, University of Northern British Columbia, Prince George, British Columbia, Canada. (
  • 3School of Geography and Environmental Sciences, Ulster University. (
  • 4School of Geography and water@leeds, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT. UK. (
  • 5US Geological Survey, Alaska Science Centre, Anchroage, AK, USA. ( )
  • 6University of Maine, USA. (
  • 7Nichols College, USA. (

The Alaskan region (comprising glaciers in Alaska, British Columbia and Yukon) contains the third largest ice volume outside of the Greenland and Antarctic ice sheets, and contributes more to global sea level rise than any other glacierised region defined by the Randolph Glacier Inventory. However, ice loss in this area is not linear, but in part controlled by glacier hypsometry as valley and outlet glaciers are at risk of becoming detached from their accumulation areas during thinning. Plateau icefields, such as Juneau Icefield in Alaska, are very sensitive to changes in Equilibrium Line Altitude (ELA) as this can result in rapidly shrinking accumulation areas. Here, we present detailed geomorphological mapping around Juneau Icefield and use this data to reconstruct the icefield during the “Little Ice Age”. We use topographic maps, archival aerial photographs, high-resolution satellite imagery and digital elevation models to map glacier lake and glacier area and volume change from the Little Ice Age to the present day (1770, 1948, 1979, 1990, 2005, 2015 and 2019 AD). Structural glaciological mapping (1979 and 2019) highlights structural and topographic controls on non-linear glacier recession.  Our data shows pronounced glacier thinning and recession in response to widespread detachment of outlet glaciers from their plateau accumulation areas. Glacier detachments became common after 2005, and occurred with increasing frequency since then. Total summed rates of area change increased eightfold from 1770-1948 (-6.14 km2 a-1) to 2015-2019 (-45.23 km2 a-1). Total rates of recession were consistent from 1770 to 1990 AD, and grew increasingly rapid after 2005, in line with regional warming.

How to cite: Davies, B., Bendle, J., McNabb, R., Carrivick, J., McNeil, C., Campbell, S., and Pelto, M.: Recent, rapid and profound changes to glacier morphology and dynamics, Juneau Icefield, Alaska, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1539,, 2021.