The 1984 eruption of Mauna Loa Volcano, Hawaii



When Mauna Loa showed signs of unrest in the spring of 1974, this volcano, the largest on earth, had not erupted since 1950. This unrest, marked by increased seismic activity and geodetic changes, led to a small summit eruption in July 1975, a type of eruption which in the past had typically been followed by flank activity within a few years. Based on this historic pattern and on the continuing inflation, a forecast was published that called for a major northeast rift zone eruption “between 2,800 and 3,000 meters elevation… sometime before the summer of 1978” [Lockwood et al, 1976]. The forecast proved correct in all details except for timing, which proved in error by almost 6 years!