Seafloor spreading centers and submarine volcanoes supply a range of elements to the ocean including: sulfur, iron, hydrogen, manganese. These elements are sourced from the earth and carried by hydrothermal fluid to the ocean. The mixing that occurs at the seafloor can be very dramatic and can create rising plumes of metal-rich, particle-laden fluid. This chemical flux carries an electron load that is poised for transfer to elements like oxygen dissolved in seawater. This creates a geochemical redox gradient that microorganisms use to derive energy for life - by a variety of chemical pathways referred to as chemosynthesis. The fact that these environments exist was only identified 40 years ago, but due to the difficulties associated with their study we still have much to learn. I study the mixing zone in which hydrothermal fluid first reacts with seawater - using ROVs, AUVs, and instruments I have developed for this purpose. In that zone, I work to understand the relative partitioning of elements between dissolved and particulate forms of matter and the processes that control whether they sink to the seafloor or are distributed to the deep-sea.
Image: The “Fuzzy Wall” filamentous microbial mats of the Mid-Cayman Rise (photo credits: Chris German, WHOI, NSF)
Image: The “Fuzzy Wall” filamentous microbial mats of the Mid-Cayman Rise (photo credits: Chris German, WHOI, NSF)
CHIP BREIER: GEOCHEMISTRY & ENVIRONMENTAL ROBOTICS