The photo is of a lava river on the Northeast Rift Zone of Mauna Loa at about 2,700 m elevation. The river is about 10 m wide at its widest.
The image was captured by Katia Krafft while she was photographing the lava streams of the 1984 eruption. Pele is the Hawaiian Goddess of Volcanoes.
Maurice and Katia Krafft studied and photographed erupting
volcanoes all over the world, witnessing and documenting more
active volcanoes than any other investigators. Their popular
books, lectures, and videotapes -- all done in their exuberent
style -- greatly increased public awareness of the nature and
dangers of volcanic eruptions. Ironically they were killed by a
pyroclastic flow from Mt. Unzen in Japan in 1991.
For more about the Kraffts, the Krafft Memorial Fund, and how to get a copy of the poster, check The Center for the Study of Active Volcanoes at the Univerity of Hawaii at Hilo.