Particle dynamics in the rising plume at Piccard Hydrothermal Field, Mid-Cayman Rise
Estapa, Margaret L.
Breier, John A.
German, Christopher R.
MetadataShow full item record
KeywordHydrothermal particulate iron fluxes; Particle size distribution; Particle inherent optical properties; In situ optical sensors; Mid-Cayman Rise; Piccard Hydrothermal Field
Processes active in rising hydrothermal plumes, such as precipitation, particle aggregation, and biological growth, affect particle size distributions and can exert important influences on the biogeochemical impact of submarine venting of iron to the oceans and their sediments. However, observations to date of particle size distribution within these systems are both limited and conflicting. In a novel buoyant hydrothermal plume study at the recently discovered high-temperature (398°C) Piccard Hydrothermal Field, Mid-Cayman Rise, we report optical measurements of particle size distributions (PSDs). We describe the plume PSD in terms of a simple, power-law model commonly used in studies of upper and coastal ocean particle dynamics. Observed PSD slopes, derived from spectral beam attenuation and laser diffraction measurements, are among the highest found to date anywhere in the ocean and ranged from 2.9 to 8.5. Beam attenuation at 650 nm ranged from near zero to a rarely observed maximum of 192 m−1 at 3.5 m above the vent. We did not find large (>100 μm) particles that would settle rapidly to the sediments. Instead, beam attenuation was well-correlated to total iron, suggesting the first-order importance of particle dilution, rather than precipitation or dissolution, in the rising plume at Piccard. Our observations at Piccard caution against the assumption of rapid deposition of hydrothermal, particulate metal fluxes, and illustrate the need for more particle size and composition measurements across a broader range of sites, globally.
Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 16 (2015): 2762–2774, doi:10.1002/2015GC005831.
Suggested CitationArticle: Estapa, Margaret L., Breier, John A., German, Christopher R., "Particle dynamics in the rising plume at Piccard Hydrothermal Field, Mid-Cayman Rise", Geochemistry, Geophysics, Geosystems 16 (2015): 2762–2774, DOI:10.1002/2015GC005831, https://hdl.handle.net/1912/7613
Showing items related by title, author, creator and subject.
Geochemistry of fluids from Earth’s deepest ridge-crest hot-springs : Piccard hydrothermal field, Mid-Cayman Rise McDermott, Jill M.; Sylva, Sean P.; Ono, Shuhei; German, Christopher R.; Seewald, Jeffrey S. (Elsevier, 2018-02-13)Hosted in basaltic substrate on the ultra-slow spreading Mid-Cayman Rise, the Piccard hydrothermal field is the deepest currently known seafloor hot-spring (4957–4987 m). Due to its great depth, the Piccard site is an ...
McDermott, Jill M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2015-02)This thesis examines the controls on organic, inorganic, and volatile species distributions in hydrothermal fluids venting at Von Damm and Piccard, two vent fields at the ultraslow spreading Mid-Cayman Rise, Earth’s deepest ...
Trophic regions of a hydrothermal plume dispersing away from an ultramafic-hosted vent-system : Von Damm vent-site, Mid-Cayman Rise Bennett, Sarah A.; Coleman, Max; Huber, Julie A.; Reddington, Emily; Kinsey, James C.; McIntyre, Cameron P.; Seewald, Jeffrey S.; German, Christopher R. (John Wiley & Sons, 2013-02-22)Deep-sea ultramafic-hosted vent systems have the potential to provide large amounts of metabolic energy to both autotrophic and heterotrophic microorganisms in their dispersing hydrothermal plumes. Such vent-systems release ...