The goal of Expedition 331 is to directly sample hydrothermally active mounds in the Okinawa Trough to obtain evidence for microbial communities. This includes variations in biomass and species diversity, as well as the function and impact of such active subseafloor microbial ecosystems underneath the hydrothermal vents.
The goal of Expedition 331 is to directly sample hydrothermally active mounds at five locations in Iheya North hydrothermal field of the Okinawa Trough to obtain evidence for microbial communities and understand their extents and ecosystems. The expedition successfully retrieved cores (columnar geological samples) at all the five locations, while the team successfully installed casing pipes (bore wall protection pipes) for chemical and microbiological monitoring at two of these drill sites (INH-4D, INH-5D). As a result, the following outcomes were achieved.
1. Discovery of the sub-seafloor hydrothermal fluid structure and hydrothermal alternation zone
2. Discovery of the sub-seafloor hydrothermal fluid reservoir
3. Discovery of the distribution and mineralogy of hydrothermal sulfide minerals: clues to uncover the hydrothermal ore genesis.
1. Discovery of the sub-seafloor hydrothermal fluid structure and hydrothermal alternation zone
2. Discovery of the sub-seafloor hydrothermal fluid reservoir
3. Discovery of the distribution and mineralogy of hydrothermal sulfide minerals: clues to uncover the hydrothermal ore genesis.
