A5067312975- Methane Hydrates and Related Phenomena
- Geochemistry and Elemental Analysis
- Geology and Paleoclimatology Research
- Paleontology and Stratigraphy of Fossils
- Marine and coastal ecosystems
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Hydrocarbon exploration and reservoir analysis
- Groundwater and Isotope Geochemistry
- Planetary Science and Exploration
- Spacecraft and Cryogenic Technologies
- Isotope Analysis in Ecology
- Seismic Imaging and Inversion Techniques
- Radioactive element chemistry and processing
- Astronomical Observations and Instrumentation
- Geological and Geophysical Studies
- Geological Modeling and Analysis
- Microbial Community Ecology and Physiology
- Offshore Engineering and Technologies
- Geophysics and Gravity Measurements
- Marine Biology and Ecology Research
- Geological formations and processes
- Atmospheric and Environmental Gas Dynamics
- Aquatic Ecosystems and Phytoplankton Dynamics
- Geological and Geochemical Analysis
Bigelow Laboratory for Ocean Sciences
2016-2024
Stockholm University
2023
University of Cambridge
2023
Geological Survey of Austria
2023
International Ocean Discovery Program
2023
University of St Andrews
2020
University of Akron
2014-2019
Oregon State University
2010-2019
University of Minnesota, Duluth
1999-2007
University of Southampton
2005
High-resolution profiles of the mass accumulation rate biogenic silica and other geochemical proxies in two piston cores from northern Lake Malawi provide a climate signal for this part tropical Africa spanning past 25,000 years. The was low during relatively dry late Pleistocene, when river flux to lake suppressed. Millennial-scale fluctuations, due upwelling intensity, Pleistocene basin appear have been closely linked Northern Hemisphere until 11 thousand years ago. Relatively cold...
Research Article| June 01, 2008 Modern iron isotope perspective on the benthic shuttle and redox evolution of ancient oceans Silke Severmann; Severmann 1Department Earth Sciences, University California–Riverside, Riverside, California 92521, USA Search for other works by this author on: GSW Google Scholar Timothy W. Lyons; Lyons Ariel Anbar; Anbar 2School Space Exploration, Department Chemistry Biochemistry, Arizona State University, Tempe, 85287, James McManus; McManus 3College Oceanic...
Research Article| August 01, 2006 Authigenic molybdenum isotope signatures in marine sediments Rebecca L. Poulson; Poulson 1College of Oceanic and Atmospheric Sciences, Oregon State University, 104 Ocean Administration Building, Corvallis, 97331-5503, USA Search for other works by this author on: GSW Google Scholar Christopher Siebert; Siebert James McManus; McManus William M. Berelson 2Department Earth University Southern California, Los Angeles, California 90089-0740, Author Article...
We present molybdenum isotope and concentration data from 14 sites in the eastern Pacific central California to Peru margin. The environments studied have been chosen represent a broad range oxidation‐reduction (redox) potential, which provide framework for behavior of this redox‐sensitive element. Manganese‐rich hemipelagic sediments tropical mean characteristic Mo signature ( δ 98/95 = −0.49 ± 0.04‰, two times standard deviation (2 SDOM) with n 14) that reflects fractionation between ocean...
Climate warming is expected to reduce oxygen (O2) supply the ocean and expand its minimum zones (OMZs). We reconstructed variations in extent of North Pacific anoxia since 1850 using a geochemical proxy for denitrification (δ(15)N) from multiple sediment cores. Increasing δ(15)N ~1990 records an expansion anoxia, consistent with observed O2 trends. However, this was preceded by longer declining trend that implies anoxic zone shrinking most 20th century. Both periods can be explained changes...
The molybdenum (Mo) stable isotope system has been applied to a variety of geochemical and environmental problems. In the absence universally accepted zero-delta reference material, different groups report their data relative adopted in-house standards. Rigorous comparison results generated in laboratories using analytical approaches is only possible if standards are identical Mo composition. To determine potential isotopic differences among various standards, δ98Mo (98Mo/95Mo) values ten...
Research Article| March 01, 2016 Key role of continental margin sediments in the oceanic mass balance Zn and isotopes Susan H. Little; Little 1Department Earth Science Engineering, Imperial College London, London SW7 2BP, UK2Institute Geochemistry Petrology, Department Sciences, ETH Zürich, Switzerland Search for other works by this author on: GSW Google Scholar Derek Vance; Vance 2Institute James McManus; McManus 3Department Geosciences, University Akron, Ohio 44325-4101, USA Silke...
Neodymium (Nd) isotopes are considered a valuable tracer of modern and past ocean circulation. However, the promise Nd isotope as water mass is hindered because there not an entirely self-consistent model marine geochemical cycle rare earth elements (REEs, which one). That is, prevailing mechanisms to describe distributions elemental isotopic completely reconciled. Here, we use published [Nd] data examine assumptions, further compare these emergent alternative models that emphasize benthic...
Research Article| November 01, 2015 Bottoms up: Sedimentary control of the deep North Pacific Ocean's εNd signature April N. Abbott; Abbott * 1College Earth, Ocean, and Atmospheric Sciences, Oregon State University, 104 CEOAS Administration Building, Corvallis, 97331-5503, USA *E-mail: aabbott@coas.oregonstate.edu Search for other works by this author on: GSW Google Scholar Brian A. Haley; Haley James McManus USA2Department Geoscience, University Akron, Ohio 44325-4101, Author Article...
Isotopic analyses of dissolved molybdenum are presented for sediment pore waters from a reducing sedimentary basin and fluids low‐temperature ridge flank hydrothermal system. δ 98/95 Mo in these range 0.8 to 3.5‰ (relative laboratory standard), demonstrating that marine reactions significantly fractionate isotopes. Within the upper 3 cm sediment, manganese oxide dissolution produces an isotopically light fluid relative seawater (mean four = 2.1 ± 0.1‰ versus 2.3 0.1‰). Below 6 depth,...
Research Article| December 01, 1999 Measurements of transience and downward fluid flow near episodic methane gas vents, Hydrate Ridge, Cascadia Michael D. Tryon; Tryon 1Scripps Institution Oceanography, University California, San Diego, La Jolla, California 92093-0220, USA Search for other works by this author on: GSW Google Scholar Kevin M. Brown; Brown Marta E. Torres; Torres 2Oregon State University, Center Oceanic Atmospheric Science, Corvallis, Oregon 97331-5503, Anne Tréhu; Tréhu James...