Biogeosciences Discussions This discussion paper is/has been under review for the journal Biogeosciences (BG). Please refer to the corresponding final paper in BG if available. Abstract We present a new geologic-time and basin-spatial scale model of the continental margin methane cycle. The model, SpongeBOB, is used to simulate evolution of the carbon cycle in a passive sedimentary continental ...

UNLABELLED The South Pacific Gyre (SPG) possesses the lowest rates of sedimentation, surface chlorophyll concentration, and primary productivity in the global oceans. As a direct result, deep-sea sediments are thin and contain small amounts of labile organic carbon. It was recently shown that the entire SPG sediment column is oxygenated and may be representative of up to a third of the global m...

Mixing models have become increasingly common tools for apportioning fluvial sediment load to various sediment sources across catchments using a wide variety of Bayesian and frequentist modeling approaches. In this study, we demonstrate how different model setups can impact upon resulting source apportionment estimates in a Bayesian framework via a one-factor-at-a-time (OFAT) sensitivity analys...

The hydrology of the subducting plate and its dewatering behavior through the shallow subduction zone is linked to the structure and deformation of the forearc prism, the nature of the seismogenic zone, the composition of seawater for selected elements, and the composition of the residual slab subducted to depths of magma generation at the volcanic arc. Two locally independent systems of fluid ...

The permafrost on the North Slope of Alaska is densely populated by shallow lakes that result from thermokarst erosion. These lakes release methane (CH4 ) derived from a combination of ancient thermogenic pools and contemporary biogenic production. Despite the potential importance of CH4 as a greenhouse gas, the contribution of biogenic CH4 production in arctic thermokarst lakes in Alaska is no...

Subglacial Lake Whillans (SLW), West Antarctica, is an active component of the subglacial hydrological network located beneath 800 m of ice. The fill and drain behavior of SLW leads to long (years to decades) water residence times relative to those in mountain glacier systems. Here, we present the aqueous geochemistry of the SLW water column and pore waters from a 38-cm-long sediment core. Stab...

Surfactant-based foam delivery technology has been studied to remediate Hanford 200 area deep vadose zone sediment. However, the surfactants and remediation amendments have an unknown effect on indigenous subsurface microorganisms. Microbial populations are important factors to consider in remediation efforts due to their potential to alter soil geochemistry. This project focuses on measuring m...