Intellectual Merit This research is a pilot program to collect samples to test models of how the Pacific Plate is recycled through subduction at the deepest ocean trench, the Challenger Deep in the Mariana Trench, using the world's first full-ocean depth hybrid remotely operated vehicle (HROV). The work serves as a test of the scientific usefulness of the deep-diving robotic sampler by having it sample and return to the surface a wide variety of rock, fluid, and biological samples from the deepest part of the seafloor. Samples taken by the HROV will permit the composition of fluids driven off the Pacific Plate as it is subducted to be studied and interpreted in terms of how these fluids can be used to understand mineral reactions that affect the mantle and crustal rock overlying the subduction zone. Because fluids carry nutrients produced by reactions in the supra-subduction-zone mantle that fuel sub-seafloor communities of microorganisms and colonies of seafloor seep organisms, this work will also provide a picture of ecosystems associated with seeps at the world's deepest ocean trench. The work involves seafloor mapping by the HROV and using the HROV to take samples of rock, fluid, sediments, and organisms from the seafloor on the overriding tectonic plate in the Marianas Trench. The project will also produce one of the first video surveys of ecosystems that occur in these extremely high-pressure and chemically unique environments.
Broader Impacts This research supports researchers at the University of Hawaii and at Woods Hole Oceanographic Institution in Massachusetts, one of which is a woman. The work helps to build capabilities of new oceanographic equipment that is capable of operating at the deepest depths in the ocean. Additional impacts are related to making the samples to be collected available to the wider scientific community.
