Hawaii Volcanoes - view of an active flow area on the flank of Kilauea

View of the active flow area on the flank of Kilauea. In the foreground, note how the lava is draining from below a solidified crust, leaving hollow spaces. Radiating heat above the hot flow creates a distorted view of flows in the distance. Another flow in the distance, the dark area in the upper center, is a small a'a flow in the midst of the pa'hoe'hoe flows. A'a forms when a lava flow has cooled enough that a thick crust of lava blocks congeals, breaks apart, and mixes and moves with the still-partly-molten flow.