title: A Far-Field Hydrothermal Plume from Loihi Seamount
abstract: An extensive helium plume in the north central Pacific emanates from Loihi Seamount on the flanks of Hawaii. The maximum helium signal is found at a depth of about 1100 meters, the same depth as the near-field plume directly above Loihi Seamount. Although this helium plume is strongest near Hawaii, where the 3He/4He ratio at a depth of about 1100 meters reaches values 28 percent above the atmospheric ratio, it can be detected quite clearly at latitude 24&deg;N, over 400 kilometers to the north. Excess 3He is also present on the same isopycnal between 15&deg;N and 20&deg;N at 135&deg;W, some 2000 kilometers east of the Hawaiian Islands.
authors.affiliation: National Oceanic and Atmospheric Administration (NOAA) Pacific Marine Environmental Laboratory, Newport, OR 97365 USA.
authors.initials: JE
authors.lastname: Lupton