Eruptions of the volcanoes on the “Big Island” of Hawaii are a relatively common occurrence. Kilauea volcano, for example, has had 48 phases of activity since it began erupting on January 3, 1983. Usually these phases last 24 hours or less and consist of lava fountains that are from several hundred to about a thousand feet high, with some lava flows extending a few miles from the vent area.a

While Mauna Loa was erupting, Kilauea also briefly roared back to life, with lava fountaining to heights of almost 700 feet. This created the unusual situation of two active volcanoes erupting simultaneously on the island​—the first time since 1868 that this had happened.

Recent Volcanic Activity

Mauna Loa has been quiet since 1984, but Kilauea, which has had 48 periodic eruptions since January 1983, changed to a continuous outpouring of lava on July 18, 1986. A daily flow of over half a million cubic yards of molten rock reached the sea last November. The eight-mile-long river of lava, which severed the Kalapana Highway, added new land to the coastline but had destroyed 26 homes by December, with another 80 still being threatened.