Erupting vents on Mauna Loa's Northeast Rift Zone near Pu‘u‘Ula‘ula (Red Hill) on Mar. 25, 1984—just hours after the eruption began—sent massive ‘A‘ā lava flows moving toward Hilo at 4 miles per hour. By the time the eruption ended on April 15, lava flows had reached to within four miles of Hilo city limits. USGS photo.
