Publication Date:
2024-02-17
Description:
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 understood (Dittmar and Stubbins, 2014; Hansell, 2013, doi:10.1146/annurev-marine-120710-100757). 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 years (Elderfield and Schultz, 1996, doi:10.1146/annurev.earth.24.1.191).
Keywords:
Akademik Mstislav Keldysh; AMK47; AMK47-Lost_City; AT18-08; Atlantis (1997); Carbon, organic, dissolved; Carbon, organic, dissolved, extracted; Comment; Comment 2 (continued); Contamination; CTD/Rosette; CTD-RO; Description; Error; Event label; Factor; Identification; ISIS; ISIS MS2000; J2-574; J2-575; J2-576; J2-579; J2-580; J2-581; J2-583; James Cook; JC042; JC080; JC082; JC42_ISIS_130; JC42_ISIS_133; JC42_ISIS_134; JC42_ISIS_141; JC80_015_CTD; JC80_ISIS_189; JC80_ISIS_190; JC80_ISIS_194; JC82_ISIS_198; JC82_ISIS_200; JC82_ISIS_202; JC82_ISIS_204; JC82_ISIS_206; JC82_ISIS_207; Juan_de_Fuca_Ridge_Axial; Juan_de_Fuca_Ridge_Endeavour; Latitude of event; Lithology/composition/facies; Longitude of event; Lost City Hydrothermal Field, Mid-Atlantic Ridge; M82/3; M82/3_719-1; M82/3_722-1; M82/3_739-1; M82/3_756-1; Magnesium; Maria S. Merian; Meteor (1986); MIR; MIR deep-sea manned submersible; MSM10/3; MSM10/3_290ROV-11; MSM10/3_300; MSM10/3_313ROV-12; Name; Ocean and sea region; Percentage; Precision; Remote operated vehicle; Remote operated vehicle Jason II; ROV; ROVJ; Sample type; Sample volume; Sampling date; Site; Solid phase extractable; South Atlantic Ocean; tropical/subtropical North Atlantic; Type; Volume; Wakamiko_Crater
Type:
Dataset
Format:
text/tab-separated-values, 4130 data points
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