Methane fluxes into the oceans are largely dependent on the methane phase as it migrates upward through the sediments. Here we document decoupled methane transport by gaseous and aqueous phases in Storfjordrenna (offshore Svalbard) and propose a three-stage evolution model for active seepage in the region where gas hydrates are...
Most authigenic carbonates previously recovered from the Cascadia slope have Sr-⁸⁷/Sr-⁸⁶ signatures that reflect shallow precipitation in equilibrium with coeval seawater. There is also evidence for carbonate formation supported by fluids that have been modified by reactions with the incoming Juan de Fuca plate (Sr-⁸⁷/⁸⁶(Sr) = 0.7071; Teichert et al.,...
High‐resolution three‐dimensional (3‐D) seismic reflection data acquired on the R/V Thomas G. Thompson in 2000 reveal a pair of bottom simulating reflections (BSRs) across a broad region of southern Hydrate Ridge, offshore Oregon. The primary BSR (BSRp) is a regionally extensive reflection that lies 120–150 m below seafloor and exhibits...
The rare earth elements (REEs) have been established as powerful tracers for a range of physiochemical processes occurring in the natural environment. They also hold significant economic importance as many technological advancements are reliant upon the REEs for their unique magnetic, luminescent, and electrochemical characteristics. In sedimentary settings, understanding the...
Methane hydrates and biohydrogen are two disparate subjects that are of interest in the growing field of alternative energy research. However, before commercial use becomes a viable option, each has challenges that need to be overcome. Methane hydrates require large investments of time and capital to locate. In this thesis,...
While bubble plumes have been acoustically imaged in the water column above marine gas
hydrate deposits in many studies, little is known about the temporal variation in plume intensity. In
July 2008, we conducted surveys using 3.5 and 12 kHz echosounders and a 75 kHz acoustic Doppler
current profiler (ADCP)...
We investigated dissolved methane distributions along a 6 km transect crossing active seep sites at 40 m water depth in the central North Sea. These investigations were done under conditions of thermal stratification in summer (July 2013) and homogenous water column in winter (January 2014). Dissolved methane accumulated below the...
Hydroacoustic data document the occurrence of 5 flare clusters and several single flares from which bubbles rise through the entire water column from an active seep site at 40 m water depth in the central North Sea. We investigated the difference in dissolved methane distributions along a 6 km transect...
The atmospheric flux of methane from the oceans is largely mitigated through microbially
mediated sulphate-coupled methane oxidation, resulting in the precipitation of authigenic
carbonates. Deep-sea carbonates are common around active and palaeo-methane seepage,
and have primarily been viewed as passive recorders of methane oxidation; their role as active
and unique...
Full Text:
pieces of
carbonate (B5 cm diameter pieces, B300 g total mass) with
2mM 15NH4Cl and 0.44mM CH4 (50% 13CH4