Lava fountain explodes from the Pu`u `O`o spatter and cinder cone on Kilauea Volcano. Dark, cooling lava fragments--tephra--fall to the ground on the cone and downwind. Below the cone, small lava fountains and flows erupt from a small fissure.

Basalt lava fountains typically erupt coarse particles (chiefly as spatter, cinders, reticulite) that are deposited within a a few kilometers to a few tens of kilometers of an erupting vent. Fine tephra (chiefly Pele's hair), however, can be blown downwind several tens of kilometers from a vent. For example, during lava fountaining episodes of Pu`u `O`o from 1984 to 1986, most of the tephra was deposited within 10 km of the vent in remote areas of Hawai`i Volcanoes National Park. The thin glassy threads of Pele's hair, however, occasionally fell to the ground as far as 65 km from the vent, reaching the towns of Hilo and Na`alehu. Following at least three high-fountaining episodes, Hawai`i County Civil Defense recommended that people disconnect and clean their rain-water catchment systems to prevent the particles from washing into their water supply.