Quantification of landslide-induced changes in glacier dynamics – literature review

Glaciers serve as markers of climate change; however, they can also respond to other events, e.g. large mass movements. Instances of large supraglacial landslides have been documented from across all major mountain ranges of the world.  Despite the large number of such events, quantitative data on glacier response to debris loading by landslide remains limited and highly incoherent. The absence of a uniform standard to report quantitative data on glacier behaviour complicates data interpretation. This study aimed to conduct an extensive literature review to compile an inventory of landslide-affected glaciers for which quantitative data are available. The generated database standardised reported data, bringing them to the same units to enable data comparison for different glaciers. The study also discussed data and methods used to obtain quantitative data and propose the most effective workflows to derive each parameter. 

Glacier response to a sudden delivery of a large quantity of debris by a landslide can include a change in ice flow velocity (acceleration or deceleration) and/or change in ablation rate, which, in consequence, can lead to mass balance modification and glacier advance. These changes can be quantified by measurements of several parameters, the most common of which are ice velocity, ice thickness, ablation, mass balance, volume, and terminus position. Based on the literature review, we were able to find only 22 glaciers for which at least some quantitative data were available on glacier response to the landslide event. Quantification of ice velocity change was the most common (available for 15 glaciers), followed by measurements of terminus position (12 glaciers) and changes in ice thickness (nine glaciers). In most cases, the ice flow velocity after the landslide increased, with the highest values reported for Baltoro glacier (Gardner and Hewitt, 1990), RGO (Stark et al., 2012) and Amalia (Van Wyk de Vries et al., 2022) glaciers. Terminus advance after the landslide was reported for nine glaciers (from 100 to 3200 m) and retreat for three glaciers (300 to 1400 m). The biggest challenges in interpreting the reported data were: different durations of observations, different modes of measurements, and different units. 

This research was funded by the National Science Centre, Poland, project number 2021/42/E/ST10/00186

References:

Gardner, J., & Hewitt, K. (1990). A Surge of Bualtar Glacier, Karakoram Range, Pakistan: A Possible Landslide Trigger. Journal of Glaciology., 36(123), 159-162. 

Stark, C., Wolovick, M., & Ekstrom, G. (2012). Glacier surge triggered by massive rock avalanche: Teleseismic and satellite image study of long-runout landslide onto RGO Glacier, Pamirs. AGU Fall Meeting Abstracts

Van Wyk de Vries, M., Wickert, A. D., MacGregor, K. R., Rada, C., & Willis, M. J. (2022). Atypical landslide induces speedup, advance, and long-term slowdown of a tidewater glacier. Geology.