Influence of volcanic activity at Mauna Loa, Hawaii, on earthquake occurrence in the Kaoiki Seismic Zone

Abstract

The Kaoiki Seismic Zone at Mauna Loa's east flank is the locus of some of the largest earthquakes on Hawaii. In this paper we examine the link of those earthquakes to volcanic activity at Mauna Loa. We calculate the changes of Coulomb failure stress along the Kaoiki faults for typical volcanic events at Mauna Loa volcano. We simulate the dislocation associated with the 1950 eruption at the Southwest Rift Zone, the 1984 eruption at the Northeast Rift Zone, and the subsequent replenishment of the shallow magma chamber. Our model calculations suggest that the earthquake occurrence in the Kaoiki Seismic Zone strongly depends on the type of volcanic activity. Kaoiki earthquakes are encouraged by dike intrusions into the Southwest Rift Zone of Mauna Loa, but discouraged by dike intrusion into the Northeast Rift Zone. Inflation of a shallow magma chamber may again encourage earthquakes.