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

最近，来自美国和英国的一个国际科学家小组在加勒比海的开曼隆起发现了一组新的、不寻常的热液喷口，这是迄今为止发现的最深的热液喷口，它们位于海底不寻常的岩石类型中。这个项目是美国国家科学基金会和美国国家航空航天局之间的一个联合活动，它跟进了这一发现，并允许对这些独特的系统进行地球化学和生物采样和分析。其中一个待勘探的地点是皮卡德喷口区，水深5000米，是已知最深的热液喷口。它有海底相分离的证据，可能是有史以来测量到的最热的喷口温度（超过450摄氏度）。另一个是冯·达姆（von Damm）喷口，它位于超镁质岩石中，烟囱由硫化物而不是碳酸盐构成，这与研究得很好的失落之城（Lost Cities）喷口系统明显不同，后者也位于超镁质岩石中。由美国国家科学基金会资助的研究人员将对通风口和附近的通风口流体化学进行取样，检查烟囱矿物学和当地的地质环境。一个重点将是确定有机化合物在多大程度上是通过非生物地球化学过程产生的。由美国宇航局资助的研究人员将对这些极端环境中的微生物和大型生物生命形式进行取样，并将他们的发现与现场的地球化学联系起来。将与其他已知的排气系统进行比较。这项工作的广泛影响包括学生和博士后的培训，以及通过国家地理杂志的参与进行的重要的公众宣传，国家地理杂志打算在他们的Oceanus电视节目中特别介绍这项研究。

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.