Elevated NH sub(4) super(+) in a neutrally buoyant hydrothermal plume

Anomalously high concentrations of NH sub(4) super(+) in hydrothermal vent discharge fluids were tracked in the resulting neutrally buoyant plume over the unsedimented Endeavour Segment, Juan de Fuca Ridge. Vertical profiles of NH sub(4) super(+) concentrations showed plume depth ( similar to 2025 m...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Deep-sea research. Part I, Oceanographic research papers Oceanographic research papers, 1998-11, Vol.45 (11), p.1891-1902
Hauptverfasser: Cowen, J P, Wen, Xiyuan, Jones, R D, Thomson, R E
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Anomalously high concentrations of NH sub(4) super(+) in hydrothermal vent discharge fluids were tracked in the resulting neutrally buoyant plume over the unsedimented Endeavour Segment, Juan de Fuca Ridge. Vertical profiles of NH sub(4) super(+) concentrations showed plume depth ( similar to 2025 m) maxima of nearly 400 nM over the Endeavour Segment's main vent field, on the same order as most subsurface NH sub(4) super(+) maxima. Plume NH sub(4) super(+) values decreased to just above background deep water values (50-70 nM) in older plume water at a station 15 km southwest of the vent field, although most of the plume NH sub(4) super(+) appears to be transported beyond the ridge axial valley. Preliminary net specific NH sub(4) super(+) removal rates determined within the plume maximum (0.04-0.13 d super(-1)) and corresponding turnover times (8-28 d) are similar to values for CH sub(4) oxidation rates. The data suggest that NH sub(4) super(+) may be a significant substrate for in situ chemolithotrophic production of organic matter in the Endeavour Segment hydrothermal plume.
ISSN:0967-0637
DOI:10.1016/S0967-0637(98)00032-6