English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Efficient removal of recalcitrant deep-ocean dissolved organic matter during hydrothermal circulation

Authors

Hawkes,  Jeffrey A.
External Organizations;

/persons/resource/prossel

Rossel Cartes,  Pamela
0 Pre-GFZ, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

Stubbins,  Aron
External Organizations;

Butterfield,  David
External Organizations;

Connelly,  Douglas P.
External Organizations;

Achterberg,  Eric P.
External Organizations;

Koschinsky,  Andrea
External Organizations;

Chavagnac,  Valérie
External Organizations;

Hansen,  Christian T.
External Organizations;

Bach,  Wolfgang
External Organizations;

Dittmar,  Thorsten
External Organizations;

External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in GFZpublic
Supplementary Material (public)
There is no public supplementary material available
Citation

Hawkes, J. A., Rossel Cartes, P., Stubbins, A., Butterfield, D., Connelly, D. P., Achterberg, E. P., Koschinsky, A., Chavagnac, V., Hansen, C. T., Bach, W., Dittmar, T. (2015): Efficient removal of recalcitrant deep-ocean dissolved organic matter during hydrothermal circulation. - Nature Geoscience, 8, 856-860.
https://doi.org/10.1038/ngeo2543


Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5006532
Abstract
Oceanic dissolved organic carbon (DOC) is an important carbon pool, similar in magnitude to atmospheric CO2, but the fate of its oldest forms is not well understood1,2. Hot hydrothermal circulation may facilitate the degradation of otherwise un-reactive dissolved organic matter, playing an important role in the long-term global carbon cycle. The oldest, most recalcitrant forms of DOC, which make up most of oceanic DOC, can be recovered by solid-phase extraction. Here we present measurements of solid-phase extractable DOC from samples collected between 2009 and 2013 at seven vent sites in the Atlantic, Pacific and Southern oceans, along with magnesium concentrations, a conservative tracer of water circulation through hydrothermal systems. We find that magnesium and solid-phase extractable DOC concentrations are correlated, suggesting that solid-phase extractable DOC is almost entirely lost from solution through mineralization or deposition during circulation through hydrothermal vents with fluid temperatures of 212–401 °C. In laboratory experiments, where we heated samples to 380 °C for four days, we found a similar removal efficiency. We conclude that thermal degradation alone can account for the loss of solid-phase extractable DOC in natural hydrothermal systems, and that its maximum lifetime is constrained by the timescale of hydrothermal cycling, at about 40 million years3.