Photograph by J.D. Griggs on 30 March 1984 Aerial view of a channelized `a`a flow on Mauna Loa Volcano, Hawai`i.

Lava flow Lava flows are masses of molten rock that pour onto the Earth's surface during an effusive eruption. Both moving lava and the resulting solidified deposit are referred to as lava flows. Because of the wide range in (1) viscosity of the different lava types (basalt, andesite, dacite, and rhyolite); (2) lava discharge during eruptions; and (3) characteristics of the erupting vent and topography over which lava travels, lava flows come in a great variety of shapes and sizes.

More about lava flows

Features and characteristics of basaltic lava flows

• Lava cascades and lava drapery form when lava pours over cliffs.
• In lava channels, standing waves and spillways are common features.
• Surges of lava occur when the supply of lava to a flow front increases.
• Methane gas explosions often occur at the edges of lava flows moving over vegetation, even as far as 100 m in front or to the side of a flow.
• How fast does basalt lava flow on Hawaiian volcanoes?

Related photo glossary terms

• Photos of effusive eruptions
• `A`a flows
• Pahoehoe flows
• Viscous lava flows form volcanic domes (also called lava domes)
• Lava flows entering the sea may form a lava delta