Methodology:

* 37_GVP_Volacanoes.shp and 13_AVTOD_Volacanoes.shp

Ice-clad volcano points

Situated in the Andes mountain chain, South America.

Coordinates provided by the Global Volcano Programme (GVP) in csv/kml format.

Holocene Occurrences: volcanoes with eruptions within the last 10,000 years.

The Global Volcanism Program (GVP) inventory was used for these shapefiles, with kml points (and associated coordinates) downloaded from the Smithsonian Institution website and converted to shapefile format. The point feature classes were then reprojected from the WGS 1984 geographical coordinate system into the UTM zone 18S and imported into ArcGIS 10.8.1 for analyses. Volcanoes were filtered according to glacier local climatic and geomorphological properties of the corresponding nearby glacier outlines (see '600_RGI_Glacier.shp' entry). Thirty-seven volcanoes hosting glaciers within a radius of 1 km from the volcanic centre, and which were classified in GVP as Holocene (having been active within the last ~12,000 years), were classed as ice-clad volcanoes and used in this study. On each ice-clad volcano, a radius buffer was applied to differentiate volcanic-glaciers located <1 km from the volcanic centre and proximal glaciers located within 1-15 km of the volcanic centre. Glaciers are expected to be most strongly influenced by volcano thermal condition when located on or close to the volcanic centre (<1 km). Beyond this distance, the volcanic (i.e., heat) influence on basal melting is anticipated to reduce progressively, and thus glacier elevation and size be increasingly controlled by climate. We set the proximal glacier buffer to 15 km to facilitate the assumption that climate within this radius, and therefore its influence on glacier elevation and ELA, can be viewed as uniform for each ice-clad volcano and the corresponding proximal glaciers.

For 37_GVP_Volacanoes.shp the study presents results from the 37 ice-clad volcanoes which host a total of 600; 526 proximal and 74 volcanic-glaciers. Fields include GVP volcano name; [Delta]cELAmean (m). They also include total annual precipitation (Mean_TAP) and mean annual air temperature (mean_AAT) between 1970 and 2000, obtained from WorldClimVersion 2.

For 13_AVTOD_Volacanoes.shp, The initial 37 ice-clad volcanoes (hosting a total of 600; 526 proximal and 74 volcanic-glaciers) were reduced to 13 volcanoes - for those with valid temperature observations captured by the ASTER Terra satellite instrument as part of the ASTER Volcanic Thermal Output Database (AVTOD). Calculated mean values for the maximum temperature anomalies were recorded for each volcano, and this was compared with each glacier's [Delta]ELAmean. Fields include GVP volcano name; mean_Tmax; [Delta]ELAmean (m). Statistical attributes were used to analyse the effect of measured volcanic thermal anomalies for these 13 ice-clad volcanoes on the glacier elevation (i.e., [Delta]cELAmean - see '139_Remapped_Glaciers.shp' ELA descriptor and calculation). Volcanic thermal anomalies (mean_Tmax) captured from the AVTOD (ASTER Volcanic Thermal Output Database) Latin America archive and [delta]Tmax: maximum temperature anomalies.

* 139_Remapped_Glaciers.shp

Glacier outline polygons existing nearby ice-clad volcanoes, output using a combination of automated and manual GIS-based mapping techniques.

Situated in the Andes mountain chain, South America.

Mapped by Mr. Stephen Howcutt

Date range: 2018 to 2019 (summer ablation seasons).

Thirteen volcanoes of the 37 initially analysed have a record of measured temperature anomalies, obtained between 2000 and 2018. A total of 139 nearby glacier outlines were re-mapped by means of a semi-automated mapping approach. This involved the application of supervised pixel training and maximum likelihood classification techniques in ArcMap 10.8.1 for extraction of polygons, using shortwave infrared fal...(63)

Data collection:

13_AVTOD_Volacanoes.shp

ASTER instrument, onboard the Terra satellite, detected and measured volcanic thermal features from space for 88 Central and South American volcanoes between 2000 and 2018, and maximum temperature anomalies ({delta}Tmax).

Data quality:

* 37_GVP_Volacanoes.shp and 13_AVTOD_Volacanoes.shp

It is recognised that magma vent and tectonic structures could be complex for specific volcanoes (e.g., Nevado del Huila in Colombia) and hence GVP points can underestimate the extent and exact location of volcanic activity (thus, glacio-volcanic interactions). However, a volcano by volcano (field based) analysis of the magmatic geometry and geothermal heat flux each volcano was not feasible.

* 600_RGI_Glaciers.shp and 139_Remapped_Glaciers.shp

RGI/GLIMS have acknowledged that an ~5% gross geometry error was observed for the Southern Andes (region 17) for RGI 6.0 glacier outlines due to the inclusion of seasonal glacier-peripheral snow and transient ice, which was misclassified as glacial ice. Our exclusion of glaciers smaller than 0.1 km2 will have removed the likelihood of including at least some erroneously mapped snow patches and seasonal ice cover. While checking and potentially re-mapping all 74 volcanic- and 526 proximal glaciers would have been unfeasible within the scope of this particular study, we attempted to correct such factors for 13 volcanoes with a record of measured thermal anomalies (analysis central to this research), for which all glaciers outlines were re-mapped by applying a semi-automated mapping process. Using this technique, we could efficiently extract glacier polygons before carrying out manual adjustments to improve alignment with the glacier margins observed on short-wave false colour composite imagery.