Long-term variability of proglacial groundwater-fed hydrological systems in an area of glacier retreat, Skeioararsandur, Iceland

Levy, A; Robinson, Z; Krause, S; Weatherill, J; Waller, R

Abstract

Proglacial groundwater-fed features, such as seeps, substantially impact proglacial geomorphology, hydrology, and ecology. However, there is a paucity of research on the impacts of climate change and glacier retreat on the extent of these important features. This paper aims to investigate the impact of glacier retreat on proglacial groundwater levels and on the extent of groundwater-fed seeps. Research has taken place in western Skeiðarársandur, the large proglacial outwash plain of Skeiðarárjökull, a retreating temperate glacier in southeast Iceland. Changes in the extent of proglacial groundwater seeps were mapped using historical aerial photographs from 1986, 1997, and 2012. Proglacial groundwater levels were monitored in shallow boreholes between 2000 and 2012. The western margin of Skeiðarárjökull has retreated approximately 1 km beyond its position in 1986. However, this retreat was punctuated by short periods of readvance. The geomorphology and groundwater systems at the site were substantially impacted by the November 1996 jökulhlaup, whose deposits altered approximately 18% of the area of groundwater seeps. The surface areas of groundwater seeps and lakes in the study area have declined by ~97% between 1986 and 2012. Most of the decline took place after 1997, when the mean annual rate of retreat increased three-fold. Groundwater levels also declined substantially between 2000 and 2012, although this trend varies spatially. The paper provides a conceptual model of the controls on proglacial shallow groundwater systems. Direct impacts of glacier retreat are suggested as the main cause for the declines in proglacial groundwater levels and in the extent of groundwater seeps. These declines are expected to adversely impact sandur ecology.

Citation

Levy, A., Robinson, Z., Krause, S., Weatherill, J., & Waller, R. (2015). Long-term variability of proglacial groundwater-fed hydrological systems in an area of glacier retreat, Skeioararsandur, Iceland. Earth Surface Processes and Landforms, 40(7), 981 -994. https://doi.org/10.1002/esp.3696

• Journal Article Type: Article
• Acceptance Date: Dec 15, 2014
• Online Publication Date: Dec 18, 2014
• Publication Date: Jun 15, 2015
• Publicly Available Date: May 26, 2023
• Journal: Earth Surface Processes And Landforms
• Print ISSN: 0197-9337
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 40
• Issue: 7
• Pages: 981 -994
• DOI: https://doi.org/10.1002/esp.3696
• Keywords: glacier retreat, proglacial groundwater, groundwater seeps, Iceland, sandur
• Publisher URL: http://dx.doi.org/10.1002/esp.3696