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Widespread influence of resuspended sediments on oceanic particulate organic carbon: Insights from radiocarbon and aluminum contents in sinking particles
Author(s) -
Hwang Jeomshik,
Druffel Ellen R. M.,
Eglinton Timothy I.
Publication year - 2010
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/2010gb003802
Subject(s) - total organic carbon , sediment , carbon fibers , radiocarbon dating , sediment trap , carbon cycle , particulates , oceanography , dissolved organic carbon , environmental chemistry , deep sea , flux (metallurgy) , environmental science , particulate organic carbon , organic matter , geology , mineralogy , chemistry , geomorphology , nutrient , paleontology , phytoplankton , ecology , materials science , ecosystem , organic chemistry , composite number , composite material , biology
Particulate organic carbon (POC) in the ocean often exhibits more depleted radiocarbon contents (lower Δ 14 C values) than expected if its sole source were POC recently synthesized by primary production and export from the overlying surface waters. An examination of available Δ 14 C data sets for sinking POC show that this phenomenon is both common and globally widespread. Also, a strong correlation is found to exist between Δ 14 C values of organic carbon and aluminum content in sinking particles that is consistent over a range of oceanic settings. Together, these findings imply that aged organic carbon associated with lithogenic material from sediment resuspension is responsible for the observed low Δ 14 C values as opposed to other processes such as incorporation of dissolved inorganic carbon or dissolved organic carbon into POC at depth. An estimate based on POC flux‐weighted Δ 14 C values shows that about 35% of sinking POC at the locations studied is derived from resuspended sediment. Our results suggest that resuspension of sediment and its subsequent lateral transport is an important component of the oceanic carbon cycle and should be considered in models of oceanic carbon export and burial.