The aqueous chemistries of two transition metal cations, Zr⁴⁺ and Nb⁵⁺, are examined and then used to develop inorganic precursor solutions. The oxides of these cations (ZrO₂ and Nb₂O₅) are deposited and characterized, and their morphological and optical properties discussed. Due to the obstacles created by niobium's aqueous chemistry, an...
With the emergence of big data and the Open Data Movement, and the wide availability to the public of large databases, Data Literacy is a necessary learning goal for students. Understanding the data process in its entirety is now a vital skillset required across industry, government, and scientific disciplines. The...
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...
Carbon isotopically based estimates of CO₂ levels have been generated from a record of the photosynthetic fractionation of ¹³C (≡εp) in a central equatorial Pacific sediment core that spans the last ~255 ka. Contents of ¹³C in phytoplanktonic biomass were determined by analysis of C37 alkadienones. These compounds are exclusive...
Application of the ²³⁰Th normalization method to estimate sediment burial fluxes in six cores from the
eastern equatorial Pacific (EEP) reveals that bulk sediment and organic carbon fluxes display a coherent regional
pattern during the Holocene that is consistent with modern oceanographic conditions, in contrast with estimates
of bulk mass...
Holocene hemipelagic deposition of terrigenous silts and clays
dominates sedimentation on most of the Oregon and Washington continental
slope. The sources of these sediments, the mechanisms causing sediment
dispersal, and the relative contributions of the various continental
sources to the marine deposits have been investigated using quantitative
mineral and geochemical...
Benthic chamber measurements of the reactants and products involved with biogenic matter diagenesis (oxygen, ammonium, nitrate, silicate, phosphate, TCO₂, alkalinity) were used to define fluxes of these solutes into and out of the sediments off southern and central California. Onshore to offshore transects indicate many similarities in benthic fluxes between...
We use flux, dissolution, and excess ²³⁰Th data from the Joint Global Ocean Flux Study and Manganese Nodule Project equatorial Pacific study Site C to assess the extent of sediment focusing in the equatorial Pacific. Measured mass accumulation rates (MAR) from sediment cores were compared to reconstructed MAR by multiplying...
The mass accumulation rates of sedimentary components (carbonate, organic carbon, opal, barite, reactive phosphate, iron, terrigenous minerals, etc.) are used in many paleoceanographic reconstructions to learn about temporal and spatial changes in surficial Earth processes including wind stress and direction, oceanic circulation, weathering rates, marine productivity and ecosystem structure, climate...
Three stations, at ∼80 m water depth on the Oregon shelf between 44.7°N and 43.9 N, were studied under hypoxic conditions in late spring and summer of 2009 to determine benthic oxygen consumption rates. Oxygen fluxes were derived from eddy correlation (EC) measurements made from an autonomous lander deployed for...