Lava tongue

Closeup of lava flowing at Kilhuea, Hawai'i Volcanoes National Park. A couple seconds after I shot this, there was a crackling sound off to my left. I looked up and about 15 feet away, a VW-sized slab of lava crust was being thust up and new lava began flowing from underneath. The NPS Ranger said "Dude, we better get out of here fast!" A few minutes later, the entire area where we had been standing was covered with fresh lava.
Kodachrome 64 with a Canon F-1N, 35-105mm