The exchange of waters between the Pacific and the Southern Oceans occurs along the eastern boundary of the South Pacific. Because water masses of the Antarctic provide a connection among the world's ocean basins, these water masses maintain the ability to influence changes in ocean circulation and climate (Lynch-Stieglitz et...
We present concentrations of germanium and silicon in sediment pore waters, basaltic formation fluids,
and bulk sediment from three ridge flank hydrothermal systems (RFHS). Basaltic formation fluids from
warm (>30°C) RFHS have much higher Ge concentrations and Ge:Si molar ratios than overlying sediment
pore waters, requiring seawater-basalt reactions to dominate...
Subsurface hydrothermal activity dominates the heat and salt budgets of the deep water column in Crater Lake, Oregon. From a time series of conductivity-temperature-depth data and data from a thermistor chain mooring, we estimate that the net hydrothermal heat flow is ~1 W m⁻² and the corresponding salt flux is...
The investigation described in this project will test the hypothesis that fluxes of carbon, barium, manganese, iron and uranium associated with fluid seepage at the San Clemente fracture zone significantly affect the geochemical budgets for these elements, and ultimately result in anomalously high benthic fluxes throughout the San Clemente basin.
A meaningful application of Mo as a paleo-redox proxy requires an understanding of Mo cycling in modern reducing environments. Stagnant euxinic basins such as the Black Sea are generally regarded as model systems for understanding euxinic systems during early Earth history. However, drawing direct parallels between the Black Sea and...
As a result of the past three years of field studies and our interpretation of these and other data from the literature, we conclude that there are inputs of hydrothermal fluids into the bottom of Crater Lake. The dissolved materials associated with these thermally and chemically enriched fluids, coupled with...
Benthic incubation chambers have been deployed in a variety of geochemical environments that provide a comprehensive geochemical framework from which to address issues related to Ba geochemistry and the use of Ba as a paleoproxy. First order budgets for barium show that in the equatorial Pacific, present rates of Ba...
Flux estimates show that upward mixing of the deep-water nitrate pool accounts for more than 85% of the total new nitrogen input to the euphotic zone of Crater Lake. Because measured primary productivity (360 mg C m-2 d-1) is 10–30 times higher than a level supported solely by the input...
We present molybdenum isotope and concentration data from 14 sites in the eastern Pacific from the
central California to the Peru margin. The environments studied have been chosen to represent a broad
range in oxidation-reduction (redox) potential, which provide a framework for the behavior of this redox-sensitive
element. Manganese-rich hemipelagic...
We present a new estimate for the crustal phosphorous sink that results from reactions among seawater, basalt, and sediment blanketing low temperature mid-ocean ridge flank hydrothermal systems. New estimates for global hydrothermal power output, sediment thickness, and the dissolved phosphate concentrations in basement formation fluids indicate that fluid flow through...
