Description: Miller and others (1998) summarize the 1988 seismic swarm at Dutton volcano as follows: "A swarm of shallow earthquakes during July and August, 1988, beneath Mount Dutton (Smithsonian Institution, 1988) sparked a volcano-seismic crisis. The activity was concentrated in three episodic sub-swarms with the largest event ML=4.0; many of these events were felt sharply at nearby communities; particularly King Cove, causing much concern. The distribution of epicenters forms a roughly linear zone which extends in a southeast direction about 10 km from the western shoulder of the volcano. The trend of the epicentral zone is parallel to the direction of maximum horizontal compression resulting from subduction of the Pacific plate and includes a prominent zone of hydrothermal alteration of the country rock. These similarities suggest that the seismic activity results from fracturing of the country rock as a dike is emplaced beneath Mount Dutton."
Wood and Kienle (1990) also report a seismic swarm at Mount Dutton during 1984-1985.