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

• Main Authors: Reinthaler, Johannes, Paul, Frank, Delgado Granados, Hugo, Rivera, Andrés, Huggel, Christian
• Format: Article in Journal/Newspaper
• Language: English
• Published: International Glaciological Society 2019
• Subjects: Institute of Geography; 910 Geography & travel; Earth-Surface Processes; Journal of Glaciology
• Online Access: https://www.zora.uzh.ch/id/eprint/178342/; https://www.zora.uzh.ch/id/eprint/178342/1/2019_area_changes_of_glaciers_on_active_volcanoes_in_latin_america_between_1986_and_2015_observed_from_multitemporal_satellite_imagery.pdf; https://doi.org/10.1017/jog.2019.30

Glaciers on active volcanoes are subject to changes in both climate fluctuations and volcanic activity. Whereas many studies analysed changes on individual volcanoes, this study presents for the first time a comparison of glacier changes on active volcanoes on a continental scale. Glacier areas were mapped for 59 volcanoes across Latin America around 1986, 1999 and 2015 using a semi-automated band ratio method combined with manual editing using satellite images from Landsat 4/5/7/8 and Sentinel-2. Area changes were compared with the Smithsonian volcano database to analyse possible glacier–volcano interactions. Over the full period, the mapped area changed from 1399.3 ± 80 km² to 1016.1 ± 34 km²(−383.2 km²) or −27.4% (−0.92% a−1) in relative terms. Small glaciers, especially in tropical regions lost more of their area compared to large and extra–tropical glaciers. Interestingly, 46 out of 59 analysed glaciers (78%) showed a decelerating shrinkage rate in the second period (−1.20% a−1 before 1999 and −0.70% a−1 after 1999). We found a slightly higher (but statistically not significant) area loss rate (−1.03% a−1) for glaciers on volcanoes with eruptions than without (−0.86% a−1).