Airborne thermal remote sensing of the volcán de colima (mexico) lava dome from 2007 to 2010

We investigate high-resolution digital photographs and infrared images of the lava dome eruption at Volcán de Colima, from 2007 to 2010. Qualitative observations provide insight into active volcanic processes (e.g. rockfalls and fracturing) and show that, as the dome advances a substantial cooled talus apron develops, which stabilizes the structure. Progressive collapse of the talus apron as it reaches the crater rim corresponds with the development of a lava lobe, extruding hot lava from deeper within the dome. Quantitative dome surface temperature timeseries show that the highest temperature hotspots migrate from the dome sides (250-380 °C) to the top (150-300 °C) and finally to the lava lobe (220-400 °C) as the structurally unstable areas expose fresh material. Net surface heat loss from the dome ranges from 5 to 30 MW, comparable to other dome forming systems. Heat budget calculations confirm that the lava dome retained a hot viscous core throughout the period 2007-2010. We propose that the mechanical stability of the Volcán de Colima dome arises from the shear strength of flanking talus which stabilizes the hot viscous core.