The distribution of barite (BaSO₄) in marine sediments has long been studied as a proxy for paleoproductivity. While pure barite is known to be a stable mineral in oxic sediments, it is also known that variations in the Sr/Ba ratio influence its solubility and liability during early diagenesis. To extract...
During four cruises in July and September of 2008 and 2009, the shipboard X-band radar was tuned to detect the modulated bands of surface roughness caused by converging and diverging currents associated with high-frequency nonlinear internal wave (NLIW) packets. The data collected was used to quantify the propagation direction (ϴp),...
The isotopic compositions of interstitial waters collected from Hydrate
Ridge during Ocean Drilling Program Leg 204 were measured to
evaluate the fluid evolution of this accretionary prism. At shallow
depths, the dissolved Cl- concentrations and δD and δ¹⁸O values of the
interstitial water reflect changes in the salinity and the...
The data presented in this report demonstrate significant improvements
in the ability to constrain trace element and Sr isotopic
concentrations in sediments overlying ridge-flank hydrothermal
systems. Improved sampling methods orchestrated by the Integrated
Ocean Drilling Program (i.e., advanced piston coring and
anoxic sample processing) enabled the collection of reactive pore...
The conventional advection-dispersion equation cannot adequately describe all processes driving
solute transport in heterogeneous systems. This dissertation focuses on the individual influences
of both chemical (Chapter 2) and physical processes (Chapters 3 and 4) which affect
solute transport. In Chapter 2 we analyzed uranium transport in natural sediment using the...
The field of nanotechnology has been rapidly developing new materials. These materials have become incorporated into consumer products and the environment after only minimal assessment of their effects on human health or the environment. The toxicity of these new nanomaterials remains unknown due to the unpredictable nature of the core...
River Influences on Shelf Ecosystems (RISE) is the first comprehensive
interdisciplinary study of the rates and dynamics governing the mixing of river and coastal
waters in an eastern boundary current system, as well as the effects of the resultant plume
on phytoplankton standing stocks, growth and grazing rates, and community...
An interlaboratory study of Mg/Ca and Sr/Ca ratios in three commercially available carbonate reference
materials (BAM RS3, CMSI 1767, and ECRM 752-1) was performed with the participation of
25 laboratories that determine foraminiferal Mg/Ca ratios worldwide. These reference materials containing
Mg/Ca in the range of foraminiferal calcite (0.8 mmol/mol to...
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 nitrogen isotope model incorporated into the three-dimensional ocean component of a global Earth system climate model designed for millennial timescale simulations. The model includes prognostic tracers for the two stable nitrogen isotopes, 14N and 15N, in the nitrate (NO3−), phytoplankton, zooplankton, and detritus variables of the...