An OBS array to investigate offshore seismicity during the 2018 Kīlauea eruption

On 3 May 2018, Kīlauea Volcano, one of the most active volcanoes in the world, entered a new eruptive phase because of a dike intrusion in the East Rift zone. One day later, an M_w 6.9 earthquake, which was likely trigged by the dike intrusion, occurred in the submarine south flank of Kīlauea Volcano. In mid-July, an ocean-bottom seismometer (OBS) array consisting of 12 stations was deployed on the submarine south flank of Kīlauea Volcano to monitor the aftershocks and lava-water interaction near the ocean entry. Eleven OBSs were recovered in mid-September. Preliminary evaluation of the data reveals a large number of seismic and acoustic events, which provide a valuable dataset for understanding flank deformation and stability as well as lava-water interaction. Here, we introduce this dataset and document notable instrument malfunctions along with some initial seismic and acoustic observations.