Mauna Loa's 1975 eruption in terms of today's Volcano Alert Level

As the sun rose above Mauna Kea (background) on July 6, 1975, eruptive fissures along the Northeast Rift Zone of Mauna Loa fed voluminous ‘a‘ā lava flows that quickly moved down the north flank of the volcano. USGS photo by D. Peterson.