Figure 7

Lava level fluctuations at Halema‘uma‘u in 2011. The thermal camera allowed continuous tracking of lava level in the lava lake at Halema‘uma‘u. During 2011, major variations occurred in level that were related to east rift zone activity. Prior to the Kamoamoa eruption, the lava level was high (a), about 60 m below the rim of the vent. When the Kamoamoa eruption occurred, depressurization (as shown by UWE ground tilt, b) and magma movement resulted in the lake to drop about 140 m and drain out of view briefly. Similar, but smaller drops, occurred during the opening of new east rift zone vents on August 3 and September 21. The thermal images have not been corrected for atmospheric or volcanic gas effects, and actual surface temperatures may be higher than the apparent temperatures shown here.