Figure 9

Lava level fluctuations at Pu‘u ‘Ō‘ō in 2011. The thermal camera allowed continuous tracking of lava rise in Pu‘u ‘Ō‘ō crater in mid-2011. Images are shown from the same camera (PTcam), which was not moved during this sequence. Following the draining of the crater during the Kamoamoa eruption in early March, lava began to refill the crater (a). By June a large (220 m long and 100 m wide) perched lava lake had formed, with steep levees (b) (corresponding visual image in Figure 3b). In July, endogenous uplift of the lake was common (c), pushing the lake level higher, almost to the level of the camera on the crater rim. On August 3, fissures opened on the lower west flank of the cone, draining the lava from the crater (d) and creating a large collapse depression about 80 m deep. The rising lava level (e) was mirrored by inflation (f), measured by the distance between GPS receivers (PUOC and JCUZ, Figure 1d) on opposite sides of the cone. 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.