@article {Cui2016238,
	title = {Biospheric and petrogenic organic carbon flux along southeast Alaska},
	journal = {Earth and Planetary Science Letters},
	volume = {452},
	year = {2016},
	pages = {238 - 246},
	abstract = {Abstract Holocene fjords store ca. 11{\textendash}12\% of the total organic carbon (OC) buried in marine sediments with fjords along southeast (SE) Alaska possibly storing half of this \{OC\} (Smith et al., 2015). However, the respective burial of biospheric (OCbio) and petrogenic \{OC\} (OCpetro) remains poorly constrained, particularly across glaciated versus non-glaciated systems. Here, we use surface sediment samples to quantify the sources and burial of sedimentary \{OC\} along \{SE\} Alaska fjord-coastal systems, and conduct a latitudinal comparison across a suite of fjords and river-coastal systems with distinctive \{OC\} sources. Our results for \{SE\} Alaska show that surface sediments in northern fjords (north of Icy Strait) with headwater glaciers are dominated by OCpetro, in contrast to marine and terrestrially-derived fresh \{OC\} in non-glaciated southern fjords. Along the continental shelf of the Gulf of Alaska, terrestrial \{OC\} is exported from rivers. Using end-member mixing models, we determine that glaciated fjords have significantly higher burial rates of \{OCpetro\} ( \~{} 1.1 {\texttimes} 10 3 ~ g \{OC\} ~ m - 2 yr - 1 ) than non-glaciated fjords and other coastal systems, making \{SE\} Alaska potentially the largest sink of \{OCpetro\} in North America. In contrast, non-glaciated fjords in \{SE\} Alaska are effective in burying marine \{OC\} (OCbio-mari) (13{\textendash}82 g  \{OC\} ~ m - 2 yr - 1 ). Globally, \{OC\} in fjord sediments are comprised of a mixture of \{OCpetro\} and fresh OCbio, in contrast to the pre-aged \{OC\} from floodplain river-coastal systems. We find that there may be a general latitudinal trend in the role of fjords in processing OC, where high-latitude temperate glacial fjords (e.g., Yakutat Bay, \{SE\} Alaska) rebury \{OCpetro\} and non-glacial mid-latitude fjords (e.g., Doubtful Sound, Fiordland) sequester \{CO2\} from phytoplankton and/or temperate forests. Overall, we propose that fjords are effective in sequestering \{OCbio\} and re-burying OCpetro. Based on our study, we hypothesize that climate change will have a semi-predictable impact on fjords{\textquoteright} \{OC\} cycling in the near future.},
	keywords = {glaciers},
	issn = {0012-821X},
	doi = {http://doi.org/10.1016/j.epsl.2016.08.002},
	url = {http://www.sciencedirect.com/science/article/pii/S0012821X16304162},
	author = {Xingqian Cui and Thomas S. Bianchi and John M. Jaeger and Richard W. Smith}
}
