Seismic and acoustic signals detected at Lo'ihi Seamount by the Hawai'i Undersea Geo-Observatory

The Hawaii Undersea Geo-Observatory (HUGO) is an ocean bottom observatory l ocated on the summit of Loihi seamount, Hawaii. An electro-optical cable co nnects the HUGO junction box to a shore station on the Big Island of Hawaii , thereby enabling the first real-time monitoring of a submarine volcano. H UGO was active for 3 months in 1998, collecting nearly continuous, real-tim e data on a high-rate hydrophone. Signals detected during that time include local as well as teleseismic earthquakes, T phases from Pacific-wide earth quakes, landslides on the submarine flank of Kilauea, and eruption sounds f rom the current Kilauea eruption. The data do not indicate a Loihi eruption during the time that HUGO was active. The variety and quality of signals d etected by the HUGO hydrophone confirms that a real-time observatory can se rve a valuable role in studies of oceanic acoustics, local and teleseismic earthquakes, and submarine eruption mechanics.