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Estuarine removal of glacial iron and implications for iron fluxes to the ocean
Author(s) -
Schroth Andrew W.,
Crusius John,
Hoyer Ian,
Campbell Robert
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl060199
Subject(s) - meltwater , glacial period , estuary , oceanography , sink (geography) , geology , deglaciation , flux (metallurgy) , environmental science , geomorphology , chemistry , geography , organic chemistry , cartography
While recent work demonstrates that glacial meltwater provides a substantial and relatively labile flux of the micronutrient iron to oceans, the role of high‐latitude estuary environments as a potential sink of glacial iron is unknown. Here we present the first quantitative description of iron removal in a meltwater‐dominated estuary. We find that 85% of “dissolved” Fe is removed in the low‐salinity region of the estuary along with 41% of “total dissolvable” iron associated with glacial flour. We couple these findings with hydrologic and geochemical data from Gulf of Alaska (GoA) glacierized catchments to calculate meltwater‐derived fluxes of size and species partitioned Fe to the GoA. Iron flux data indicate that labile iron in the glacial flour and associated Fe minerals dominate the meltwater contribution to the Fe budget of the GoA. As such, GoA nutrient cycles and related ecosystems could be strongly influenced by continued ice loss in its watershed.