[MIS02-P03] Interaction between submarine landslides and subseafloor sedimentary microbiome: Chikyu SCORE Expedition 910 off Cape Erimo
Keywords:Chikyu SCORE, Deep biosphere, Mass transport deposit
In 2017, we conducted the Chikyu’s first SCORE Expedition 910 at the Hidaka Trough off Cap Erimo and obtained sediment cores down to 100 meters below the seafloor. In the core column, four intervals of deformed sediments were identified, indicating the occurrences of multiple submarine landslides in this area. In those deformed sediment intervals, we observed no clear anomaly in the profile of cell abundance, which decrease with sediment depth as generally seen in the other subserfloor sediments. In addition, pore water chemistry data do not show clear anomaly either, indicating recovery of sediment geochemistry from the turbation caused by landslides. While both profiles of microbial cell abundance and pore water geochemistry did not show anomaly in the deformed sediment intervals, the DNA-based analyses, showed some unusual appearances of microbial taxa relative to the depth, suggesting the potential migration of microbes from the upper horizons by submarine landslides.
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