English: Pāhoehoe Lava flows in the open lava channel (not in a Lava tube) with overflows at both sides. The image was taken at The Big Island of Hawaii. The lava flow is due to July 21, 2007 fissure eruption at Kīlauea volcano. The channel is crusting over with a v-shaped opening pointing upstream. The crusting-over process usually starts at the upstream end, the crust grows downstream for a considerable distance, then the crust founders and sinks opening the channel to crusting over again. The main channel and overflows show perched nature of this kind of lava channels. The picture was taken from a helicopter. The link to the map of the flow by USGS.