Unravelling eruption dynamics at El Reventador, Ecuador: linking the physiochemical properties of volcanic ash with geophysical, geochemical and satellite remote sensing data

Abstract

The physiochemical properties of volcanic ash are determined by magma ascent and eruption dynamics and provide important insights into controls on the timing and style of volcanic eruptions. However, linking petrological observations to monitoring parameters remains challenging. Here we investigate the relationships between geophysical, geochemical and satellite remote sensing data with the physiochemical properties of volcanic ash to better understand eruptive dynamics at El Reventador volcano, Ecuador. Between 2016 and 2019, eruptive activity at El Reventador was characterised by frequent explosions interspersed with effusive activity from two summit vents. We found that: (1) periods of predominantly effusive behaviour were defined by ash samples with the lowest proportions of juvenile grains, frequent, more intense thermal anomalies and frequent (ca. every 25 min) but low-energy explosions that produced lower average ash column heights (< 1200 m above the summit) and; (2) periods of predominantly explosive behaviour were defined by ash samples with the highest proportions of juvenile grains and also vesicular juvenile grains, low thermal anomalies and less frequent (ca. every 70 min), higher-energy explosions that produced higher average eruption column heights (> 1500 m above the summit). Our study shows that there are strong correlations between the physiochemical properties of erupted material and the multiparametric monitoring data which in turn link to the type of surface activity observed. As a result, the development of physical conduit models and interpretations of eruptive dynamics are made more robust combining both monitoring data and the physical properties of eruptive products.