During the beginning of the outburst eruption, thermal emission is dominated by strong, 1–3 μm infrared radiation. It is produced by a large amount of exposed, fresh lava within the fountains at the eruption source vent.
In the early phases of the explosive eruption, heat emission is mainly comprised of strong, 1–3 μm infrared radiation. This occurs due to the presence of large quantities of freshly erupted lava in the fountains emanating from the vent, which are a characteristic feature of volcanic activity.