Thermal imagery video of Halema`uma`u lava lake cycles

This video shows thermal imagery of the vent inside Halema`uma`u crater. The lava surface, about 130 yards below the vent rim, is clearly visible and can be seen undergoing cycles of filling and drainback. Filling phases entail a rapidly rising lava level with intense (and loud) spattering, followed by a gradual phase of lava draining back down the conduit. These cycles are thought to be controlled by episodic gas accumulation and release in the conduit. The thermal image sequence is sped up by a factor of 15.