Collaborative Research: Venting Outside the Box - Extending the Known Limits to Seafloor Hydrothermal Circulation and the Chemosynthetic Life it Supports

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

A new and unusual set of hydrothermal vents that are the deepest yet discovered and that are hosted in unusual rock types on the seafloor have been found recently on the Cayman Rise in the Caribbean Sea by an international teams of scientists from the US and UK. This project is a joint activity between NSF and NASA that follows up on this discovery and allows the geochemical and biological sampling and analysis of these unique systems. One of the sites to be explored is the Piccard vent field which at 5000 meters water depth is the deepest hydrothermal vent site known. It has evidence for phase separation at the seafloor and may host the hottest vent temperatures ever measured (in excess of 450C). The other is the von Damm vent site which is hosted in ultramafic rocks and has chimneys made of sulfides instead of carbonates, making it distinctly different from the well studied Lost Cities vent system which is also hosted in ultramafic rocks. Researchers funded by NSF will sample vent and near vent fluid chemistry, examine chimney mineralogy, and the local geological setting. A focus will be to determine the extent to which organic compounds are being made through abiotic geochemical processes. Researchers funded by NASA will sample the microbial and macrobiological life forms that inhabit these extreme environments and link their findings to the site geochemistry. Comparisons will be made with other known vent systems. Broader impacts of the work include student and postdoc training and significant public outreach through engagement of National Geographic which intends to feature this research on their Oceanus television program.