Impacts of the Calbuco eruption, Chile (NERC grant NE/N007271/1)

Volcanic ash samples were collected and analysed following the 2015 eruption of Calbuco volcano, Chile. Datasets uploaded are: Calbuco2015 Probe Data - excel Calbuco2015 Locations and Grain Size – excel Calbuco Deposit Measurements grl54177-sup-0002-tables3 Published as supplement to A.R. van Eaton et al (2016) Volcanic lightning and plume behavior reveal evolving hazards during the April 2015 eruption of Calbuco volcano, Chile, Geophysical Research Letters 43 (7), 3563-3571 Electron Probe Micro Analysis Major element compositions of plagioclase, groundmass glass and melt inclusions were analysed with a JEOL JXA-8600 wavelength-dispersive electron microprobe (EMP), equipped with four spectrometers, at the Research Laboratory for Archaeology and the History of Art, University of Oxford using a defocused beam (5¿m), low beam current (4nA) and accelerating voltage of 15 kV. Full analytical conditions are detailed in Rawson et al. (2015). Secondary standards used were Gor128-G and StHs/80-G for glass (Jochum et al., 2006). Glass (melt inclusion and groundmass) totals were normalised to 100% to account for variable secondary hydration. Stoichiometry and charge balancing was used to determine the amount of Fe2O3 and FeO in plagioclase. Pyroxene and magnetite grains were analysed with a defocused beam (5¿m), higher beam current (10nA), and an accelerating voltage of 15 kV. Secondary standards used were hornblende (USNM 111356), Pyrope (USNM 1143968) and ilmenite (USNM 96189; (Jarosewich et al., 1980). Stoichiometry and charge balancing was used to determine the amounts of Fe2O3 and FeO, following Droop (1987). Thickness and Grain size analysis Ash fallout thicknesses were measured in the field shortly after deposition, and samples collected for follow-up analysis of grainsize and chemical composition. Grain size analysis was conducted using a Malvern Laser Particle Sizer Mastersizer 2000 at the University of Oxford.