T-Limit of the Deep Biosphere off Muroto, IODP Expedition 370 Field Study uri icon

DCO ID 11121/7618-4547-4265-7749-CC


  • Biomass of subseafloor microbial life is at least comparable to that in the oceans. The massive buried biosphere plays an important on a global scale, in carbon sequestration, element cycles, and Earth's evolution. In 2012, IODP Expedition 337 unveiled the presence of microbial life at almost 2.5 km below the sea floor (Inagaki et al. 2015). But a central question of deep biosphere community remained unsolved; what is the vertical extent of the habitable zone on Earth, and by inference, the factors that limit life’s maximum depths?
    IODP Expedition 370, T-Limit of the Deep Biosphere off Muroto, will tackle this question by drilling through the sediments in the central Nankai Trough off Japan. Anomalously high heat flow regimes in this area result in temperatures of about 130°C at the sediment/basement interface (1210 mbsf), and make the site ideal target for an in-depth examination of subseafloor microbial life close its upper temperature limit.

date/time interval

  • September 13, 2016 - November 11, 2016

geographic focus