@article {2883,
	title = {Clumped Isotopes Link Older Carbon Substrates With Slower Rates of Methanogenesis in Northern Lakes},
	journal = {Geophysical Research Letters},
	volume = {47},
	year = {2020},
	month = {Apr-03-2022},
	abstract = {The release of long-stored carbon from thawed permafrost could fuel increased methanogenesis in northern lakes, but it remains unclear whether old carbon substrates released from permafrost are metabolized as rapidly by methanogenic microbial communities as recently produced organic carbon. Here, we apply methane (CH4) clumped isotope (Δ18) and 14C measurements to test whether rates of methanogenesis are related to carbon substrate age. Results from culture experiments indicate that Δ18 values are negatively correlated with CH4 production rate. Measurements of ebullition samples from thermokarst lakes in Alaska and glacial lakes in Sweden indicate strong negative correlations between CH4 Δ18 and the fraction modern carbon. These correlations imply that CH4 derived from older carbon substrates is produced relatively slowly. Relative rates of methanogenesis, as inferred from Δ18 values, are not positively correlated with CH4 flux estimates, highlighting the likely importance of environmental variables other than CH4 production rates in controlling ebullition fluxes.},
	keywords = {clumped isotopes, ebullition flux, lakes, methane, permafrost, radiocarbon},
	issn = {0094-8276},
	doi = {10.1029/2019GL086756},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GL086756},
	author = {Douglas, Peter M. J. and Gonzalez Moguel, Regina and Walter Anthony, Katey M. and Wik, Martin and Crill, Patrick M. and Dawson, Katherine S. and Smith, Derek A. and Yanay, Ella and Lloyd, Max K. and Stolper, Daniel A. and Eiler, John M. and Sessions, Alex L.}
}
@article {2851,
	title = {Seafloor fluid seeps on Kimki Ridge, offshore southern California: Links to active strike-slip faulting},
	journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
	volume = {150},
	year = {2018},
	month = {Jan-04-2018},
	pages = {82 - 91},
	abstract = {The Kimki Ridge fluid seeps are located in western Catalina Basin about 60 km southwest of the southern California mainland and at a water depth of approximately 1100 m. Multichannel seismic reflection profiles collected by the U.S. Geological Survey (USGS) in 2014 show acoustic transparency within the Kimki Ridge, suggesting the possibility of fluid seeps and possible sub-seafloor fluid pathways. Subsequent multibeam bathymetric and backscatter intensity data collected during a cooperative University of Washington/USGS cruise in early 2016 show subtle seafloor buildups with high acoustic backscatter (reflectivity) in three places along Kimki Ridge, supporting the existence of fluid seepage. A Remotely Operated Vehicle (ROV) dive, conducted as part of the Nautilus Exploration Program, took place in August 2016 to confirm the presence of these previously unknown seeps and document their characteristics as well as those of any associated biological communities. Two of the three seeps were explored by ROV, and showed abundant evidence of fluid seepage, including characteristic algal mats, chemosynthetic clams, and authigenic carbonate formation. The seeps are comprised of carbonate buildups 1{\textendash}3 m thick and 300{\textendash}500 m across. Within these areas, we interpret broad crater-like depressions 30{\textendash}50 m across and 1{\textendash}2 m deep to be individual seep vents. The seep areas appear to be broad zones of diffuse seepage that support chemosynthetic biologic communities; however, active venting was not observed. Geochemical analyses of rock samples collected from the seeps indicate microbially driven anaerobic oxidation of methane at or near the sediment water interface. Seismic-reflection profiles show chimney-like fluid pathways along the limbs and in the axis of the fold forming Kimki Ridge, and evidence of methane in shallow sediments can be traced into the adjacent Catalina Basin. A system of closely spaced faults located at the axis of the Kimki Ridge anticline may serve as pathways to allow fluid flow to the seafloor. Our data are consistent with other studies that suggest that transpression is an important component in the formation and localization of fluid seeps in a strike-slip setting, implying that seep formation may be a common occurrence at fault stepovers or transpressional bends in strike-slip systems.},
	keywords = {California Inner Continental Borderland, E/V Nautilus, Faulting, methane, Seepages},
	issn = {09670645},
	doi = {10.1016/j.dsr2.2017.11.001},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0967064517301595},
	author = {Conrad, James E. and Prouty, Nancy G. and Walton, Maureen A.L. and Kluesner, Jared W. and Maier, Katherine L. and McGann, Mary and Brothers, Daniel S. and Roland, Emily C. and Dartnell, Peter}
}
@book {2724,
	title = {Using Stable and Radiocarbon Analyses as a Forensic Tool to Find Evidence of Oil in the Particulates of the Water Column and on the Seafloor Following the 2010 Gulf of Mexico Oil Spill},
	year = {2018},
	pages = {639 - 650},
	publisher = {Elsevier},
	organization = {Elsevier},
	abstract = {Over 600 million liters of oil and copious amounts of methane were released into the Gulf of Mexico between April 20, 2010 and July 15, 2010. We used stable and radiocarbon analyses as a forensic tool to trace these hydrocarbons from the Deepwater Horizon (DwH) well into suspended particulate organic carbon (POCsusp), sinking particulate organic carbon (POCsink), and sedimentary organic carbon on the seafloor. POCsusp samples were considerably depleted both in δ13C and Δ14C relative to surface production, with δ13C and Δ14C values as low as -37.2{\textperthousand} and -618{\textperthousand}, respectively. POCsink time series data revealed a modern Δ14C value due to a large diatom bloom in early September 2010, but values became depleted as oil contaminated particles continued to descend in the water column until the end of the year. Sediment cores collected in the vicinity of the DwH wellhead revealed evidence of oil contamination in the surface layer (0{\textendash}1 cm), as indicated by a depletion in Δ14C values compared to the layers below the surface. In addition to providing evidence of oil contamination using stable and radiocarbon analyses, our study was consistent with the existence of a pathway by which spilled oil was deposited onto the seafloor.},
	keywords = {Deepwater Horizon, isotopes, methane, Petrocarbon, POCsin, POCsusp, Sediment},
	isbn = {9780128044346},
	doi = {10.1016/B978-0-12-804434-6.00029-X},
	url = {https://linkinghub.elsevier.com/retrieve/pii/B978012804434600029X},
	author = {Bosman, Samantha H. and Chanton, Jeffrey P. and Rogers, Kelsey L.}
}
@article { ISI:000312696400053,
	title = {Radiocarbon evidence that carbon from the Deepwater Horizon spill entered the planktonic food web of the Gulf of Mexico},
	journal = {ENVIRONMENTAL RESEARCH LETTERS},
	volume = {7},
	number = {{4}},
	year = {2012},
	month = {OCT-DEC},
	type = {Article},
	abstract = {The Deepwater Horizon (Macondo) oil spill released large volumes of oil and gas of distinct carbon isotopic composition to the northern Gulf of Mexico, allowing Graham et al (2010 Environ. Res. Lett. 5 045301) to use stable carbon isotopes (delta C-13) to infer the introduction of spilled oil into the planktonic food web. Surface ocean organic production and measured oil are separated by 5-7 parts per thousand in stable carbon isotope (delta C-13) space, while in radiocarbon (Delta C-14) space these two potential sources are separated by more than 1000 parts per thousand. Thus radiocarbon isotopes provide a more sensitive tracer by which to infer possible introduction of Macondo oil into the food web. We measured Delta C-14 and delta C-13 in plankton collected from within 100 km of the spill site as well as in coastal and offshore DIC (dissolved inorganic carbon or Sigma CO2) to constrain surface production values. On average, plankton values were depleted in C-14 relative to surface DIC, and we found a significant linear correlation between Delta C-14 and delta C-13 in plankton. Cumulatively, these results are consistent with the hypothesis that carbon released from the Deepwater Horizon spill contributed to the offshore planktonic food web. Our results support the findings of Graham et al (2010 Environ. Res. Lett. 5 045301), but we infer that methane input may be important.},
	keywords = {carbon isotope, Gulf oil spill, methane, petroleum hydrocarbon, radiocarbon},
	issn = {1748-9326},
	doi = {10.1088/1748-9326/7/4/045303},
	author = {Chanton, J. P. and Cherrier, J. and Wilson, R. M. and Sarkodee-Adoo, J. and Bosman, S. and Mickle, A. and Graham, W. M.}
}
