An intermediate-depth source of hydrothermal 3He and dissolved iron in the North Pacific

•The Loihi Seamount is a significant source of dissolved iron to the North Pacific.•The 3He:iron ratio is similar to East Pacific Rise in the South Pacific.•The flux of 3He is ∼10 moles per year.•The dissolved iron flux is ∼108 moles per year.•Some of this iron may upwell in the North Pacific to fuel biological production.