Matches in SemOpenAlex for { <https://semopenalex.org/work/W4221123145> ?p ?o ?g. }
- W4221123145 endingPage "312" @default.
- W4221123145 startingPage "288" @default.
- W4221123145 abstract "We examined iron biogeochemistry in continental margin sediments along the western side of the Antarctic Peninsula (WAP) to explore the connections between iron redox cycling and other sediment biogeochemical processes, and to specifically examine the role of sediments as a source of iron to support Southern Ocean primary productivity. Total iron (FeT) in WAP sediments ranged from ∼4 to 6 wt% Fe and showed no consistent depth variations. Total iron oxides (FeOx) represented ∼20–30% of FeT in WAP surface sediments and was comprised of two types of materials: Feox1, which is thought to contain amorphous, highly reactive, and poorly crystalline iron oxides such as ferrihydrite and lepidocrocite, and Feox2, which is thought to contain magnetite and less reactive, more crystalline iron oxides such as goethite and hematite. Absolute and relative concentrations of FeOx declined with sediment depth, presumably due to reductive dissolution, and there was also a major depth change in the speciation of FeOx. Near the sediment surface ∼30% of FeOx was Feox1, while below ∼30 cm Feox1 was almost completely consumed and therefore here virtually all FeOx was Feox2. Consistent with these observations, a simple reaction-transport model applied to the depth distributions of Feox1 and Feox2 iron in WAP shelf sediments suggested a ∼20-fold difference in the relative reactivity of these different oxides towards reductive dissolution (Feox1 > Feox2). At several stations profiles of pore water dissolved iron and solid phase Feox1 can be explained by steady state iron redox cycling. In contrast, profiles at other stations showed evidence of non steady-state iron redox cycling. Seasonal changes in the sediment organic carbon rain rate at these sites may explain this latter behavior. Differences in the behavior of iron at different sites may be related to the interplay between changes in sediment redox conditions and their impact on bioturbation and iron redox cycling. Sediment iron sources to the water column include dissolved iron (∼Fe2+) benthic fluxes as well as sediment resuspension processes that mix iron oxides (i.e., Feox1) found in surface sediments into the bottom waters. The impact these benthic iron sources will have on surface water iron concentrations (and eventually primary production) will depend on transport processes that move this iron from deeper waters to surface waters. They will also depend on chemical transformations in the water column that affect iron bioavailability. While sediment processes (in general) appear to be an important source of iron to Southern Ocean surface waters, there is large uncertainty in their magnitude. However, the results presented here demonstrate that the suspended sediment flux of amorphous iron oxides needs to be considered when discussing sediment iron sources to Southern Ocean surface waters." @default.
- W4221123145 created "2022-04-03" @default.
- W4221123145 creator A5042032867 @default.
- W4221123145 creator A5066463041 @default.
- W4221123145 date "2022-06-01" @default.
- W4221123145 modified "2023-10-16" @default.
- W4221123145 title "Iron biogeochemistry in sediments on the western continental shelf of the Antarctic Peninsula" @default.
- W4221123145 cites W1511757587 @default.
- W4221123145 cites W1601823087 @default.
- W4221123145 cites W1601989133 @default.
- W4221123145 cites W1848087908 @default.
- W4221123145 cites W1849030221 @default.
- W4221123145 cites W1969394853 @default.
- W4221123145 cites W1975082687 @default.
- W4221123145 cites W1977155514 @default.
- W4221123145 cites W1978156487 @default.
- W4221123145 cites W1986404326 @default.
- W4221123145 cites W1987267593 @default.
- W4221123145 cites W1990538052 @default.
- W4221123145 cites W1990611318 @default.
- W4221123145 cites W1990648220 @default.
- W4221123145 cites W1991569790 @default.
- W4221123145 cites W1995182573 @default.
- W4221123145 cites W1997884189 @default.
- W4221123145 cites W1998014287 @default.
- W4221123145 cites W1999392948 @default.
- W4221123145 cites W2004035190 @default.
- W4221123145 cites W2004373591 @default.
- W4221123145 cites W2007443159 @default.
- W4221123145 cites W2007446886 @default.
- W4221123145 cites W2008317727 @default.
- W4221123145 cites W2008772238 @default.
- W4221123145 cites W2011510050 @default.
- W4221123145 cites W2020607844 @default.
- W4221123145 cites W2021252234 @default.
- W4221123145 cites W2024172823 @default.
- W4221123145 cites W2029758027 @default.
- W4221123145 cites W2032275573 @default.
- W4221123145 cites W2034557601 @default.
- W4221123145 cites W2035041372 @default.
- W4221123145 cites W2035398133 @default.
- W4221123145 cites W2036677156 @default.
- W4221123145 cites W2040710238 @default.
- W4221123145 cites W2042505431 @default.
- W4221123145 cites W2043668123 @default.
- W4221123145 cites W2050780574 @default.
- W4221123145 cites W2052727955 @default.
- W4221123145 cites W2053751618 @default.
- W4221123145 cites W2069398064 @default.
- W4221123145 cites W2069934447 @default.
- W4221123145 cites W2072172339 @default.
- W4221123145 cites W2073177663 @default.
- W4221123145 cites W2074144717 @default.
- W4221123145 cites W2075306795 @default.
- W4221123145 cites W2077992860 @default.
- W4221123145 cites W2082756728 @default.
- W4221123145 cites W2086635295 @default.
- W4221123145 cites W2089490929 @default.
- W4221123145 cites W2094573651 @default.
- W4221123145 cites W2095081744 @default.
- W4221123145 cites W2100612502 @default.
- W4221123145 cites W2100820965 @default.
- W4221123145 cites W2102761435 @default.
- W4221123145 cites W2104953002 @default.
- W4221123145 cites W2106651308 @default.
- W4221123145 cites W2106949536 @default.
- W4221123145 cites W2111761293 @default.
- W4221123145 cites W2117031434 @default.
- W4221123145 cites W2119260817 @default.
- W4221123145 cites W2121064853 @default.
- W4221123145 cites W2122241717 @default.
- W4221123145 cites W2122338764 @default.
- W4221123145 cites W2130723382 @default.
- W4221123145 cites W2135113899 @default.
- W4221123145 cites W2137899037 @default.
- W4221123145 cites W2142462683 @default.
- W4221123145 cites W2147547928 @default.
- W4221123145 cites W2148911019 @default.
- W4221123145 cites W2154836565 @default.
- W4221123145 cites W2161582133 @default.
- W4221123145 cites W2167881866 @default.
- W4221123145 cites W2169517261 @default.
- W4221123145 cites W2190193008 @default.
- W4221123145 cites W2220777251 @default.
- W4221123145 cites W2317447564 @default.
- W4221123145 cites W2318750847 @default.
- W4221123145 cites W2321163669 @default.
- W4221123145 cites W2528176786 @default.
- W4221123145 cites W2568121535 @default.
- W4221123145 cites W2594031586 @default.
- W4221123145 cites W2611993208 @default.
- W4221123145 cites W2736868277 @default.
- W4221123145 cites W2761177165 @default.
- W4221123145 cites W2768675666 @default.
- W4221123145 cites W2782758121 @default.
- W4221123145 cites W2800725800 @default.
- W4221123145 cites W2801782637 @default.
- W4221123145 cites W2804505658 @default.