Journal of Glaciology
Reinthaler and others (2019), hereafter Reinthaler 2019, characterize ice extent on 59 volcanoes in Latin America from 1986 to 2015 using Landsat and Sentinel-2 imagery to quantify the impact of climate and eruptions on glacier evolution. Here we compare the work of Reinthaler 2019 with Kochtitzky and others (2018), hereafter Kochtitzky 2018, on Nevado Coropuna Ice Cap, and present some new analysis to highlight the challenges of seasonal snow coverage in the delineation of glaciers (Pfeffer and others, 2014; Paul and others, 2017). Nevado Coropuna Ice Cap has received significant attention (e.g. Racoviteanu and others, 2007; Silverio and Jaquet, 2012; Veettil and others, 2016; Kochtitzky and others, 2018; Reinthaler and others, 2019) and is a sentinel for climate change as the biggest ice body in the tropics, in addition to being important for regional water resources for ∼110 000 residents downstream (Kochtitzky and others, 2018). However, few studies were able to avoid including transient snow cover in glacier delineations leading to overestimations of ice extent at Nevado Coropuna Ice Cap by as much as 150% (Kochtitzky and others, 2018). This is particularly problematic because overestimation of glacier area, particularly in early years of the satellite record, can lead to erroneous glacier retreat rates. Overestimating glacier retreat rates could one, be mistakenly interpreted as caused by an increase in volcanic activity and two, falsely suggest water resources could run dry sooner than is likely.
Kochtitzky, William, and Benjamin Edwards. "Comments on ‘Area Changes of Glaciers on Active Volcanoes in Latin America’ by Reinthaler and others (2019)." Journal of Glaciology 66, no. 257 (2020): 520-522. https://www.cambridge.org/core/journals/journal-of-glaciology/article/comments-on-area-changes-of-glaciers-on-active-volcanoes-in-latin-america-by-reinthaler-and-others-2019/664F6656140EB0B626AD001D0BD13777