Volcanic impacts on modern glaciers: A global synthesis

Abstract

Volcanic activity can have a notable impact on glacier behaviour (dimensions and dynamics). This is evident from the palaeo-record, but is often difficult to observe for modern glaciers. However, documenting and, if possible, quantifying volcanic impacts on modern glaciers is important if we are to predict their future behaviour (including crucial ice masses such as the West Antarctic Ice Sheet) and to monitor and mitigate glacio-volcanic hazards such as floods (including jökulhlaups) and lahars. This review provides an assessment of volcanic impacts on the behaviour of modern glaciers (since AD 1800) by presenting and summarising a global dataset of documented examples. The study reveals that shorter-term (days-to-months) impacts are typically destructive, while longer-term (years-to-decades) are more likely protective (e.g., limiting climatically driven ice loss). However, because these events are difficult to observe, particularly before the widespread availability of global satellite data, their 2 frequency and importance are likely underestimated. The study also highlights that because the frequency and nature of volcano-glacier interactions may change with time (e.g., glacier retreat may lead to an increase in explosive volcanic activity), predicting their future importance is difficult. Fortunately, over coming years, continued improvements in remotely sensed data will increase the frequency, and enhance the quality, of observations of volcanic impacts on glaciers, allowing an improved understanding of their past and future operation.

Area changes of glaciers on active volcanoes in Latin America between 1986 and 2015 observed from multi-temporal satellite imagery

“…Whereas eruption frequency and VEI are easily quantifiable using the volcano database, non-eruptive features such as geothermal heat release are difficult to quantify and its contribution to glacier area reduction is difficult to estimate (Barr and others, 2018). Several papers (Hamza and Muñoz, 1996; Davies, 2013; Vieira and Hamza, 2014) tried to quantify geothermal heat flux on a continental scale.…”

“…The latter is particularly important for glaciers located on active volcanoes, as volcanic eruptions can cause destruction of ice, influence basal sliding, the surface albedo due to ejected pyroclastic material and even cause glacier advances (Rivera and others, 2012). Furthermore, glaciers on active volcanoes can cause hazards such as lahars, jökulhlaups, slope instabilities and volcanic collapses, all exposing the local population to high risk (Lescinsky and Fink, 2000; Huggel and others, 2007b; Capra and others, 2013; Delgado Granados and others, 2015; Barr and others, 2018). Accordingly, permanent monitoring of the glaciers on volcanoes is essential to better understand the interaction between glaciers and volcanoes and protect the population from such hazards.…”

Global Disappearance of Tropical Mountain Glaciers: Observations, Causes, and Challenges

“…Other regional and local natural and anthropogenic phenomena like volcanic eruptions and mining activities may also influence the pace of glacier retreat [45]. The presence of particulate matter such as volcanic dust or black carbon that deposits on the glacier surface reduces the ice's surface albedo, resulting in enhanced melting [46].…”

The interpretative value of transformed tephra sequences

“…There has, however, been comparatively limited work on the immediate posteruption transformations that occur after tephra is deposited on ice and snow (e.g. Hunt, 1994;Kirkbride and Dugmore, 2003;Richardson and Brook, 2010;Nield et al, 2013;Barr et al, 2018).…”