Mauna Loa 1950 eruption: A lot of lava with little warning

During the Mauna Loa 1950 eruption, three large, fast-moving lava flows advanced down the west flank of the volcano, each crossing the main highway before reaching the ocean. The Ka‘apuna flow, shown here, traveled from the Southwest Rift Zone vent (7,800 ft elevation) to the coast in just 17 hours, creating a huge steam plume as lava flowed into the sea. The glowing edges and fast-moving channels of the 10- to 25-ft thick ‘A‘ā flow appear white in this June 2, 1950, aerial image. Photo courtesy of Air National Guard, 199th Fighter Squadron.