A5084055172- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Marine and coastal ecosystems
- Arctic and Antarctic ice dynamics
- Atmospheric and Environmental Gas Dynamics
- Oceanographic and Atmospheric Processes
- Atmospheric chemistry and aerosols
- Radioactivity and Radon Measurements
- Radioactive contamination and transfer
- Geochemistry and Elemental Analysis
- Marine Biology and Ecology Research
- Hydrocarbon exploration and reservoir analysis
- Groundwater and Isotope Geochemistry
- Climate change and permafrost
- Geological Studies and Exploration
- Paleontology and Stratigraphy of Fossils
- Geological and Geochemical Analysis
- Cryospheric studies and observations
- Geological formations and processes
- earthquake and tectonic studies
- Ocean Acidification Effects and Responses
- Isotope Analysis in Ecology
- Mercury impact and mitigation studies
- Planetary Science and Exploration
- Climate variability and models
Florida International University
2015-2025
University of Miami
2002-2014
Bermuda Institute of Ocean Sciences
2004
Oregon State University
1985-1990
Lamont-Doherty Earth Observatory
1980-1983
Columbia University
1980-1983
United States Geological Survey
1983
Transects of the submersible Alvin across rock outcrops in Oregon subduction zone have furnished information on structural and stratigraphic framework this accretionary complex. Communities clams tube worms, authigenic carbonate mineral precipitates, are associated with venting sites cool fluids located a fault-bend anticline at water depth 2036 meters. The distribution animals carbonates suggests up-dip migration from both shallow deep sources along permeable strata or fault zones within...
Arctic Ocean properties and processes are highly relevant to the regional global coupled climate system, yet still scarcely observed, especially in winter. Team OCEAN conducted a full year of physical oceanography observations as part Multidisciplinary drifting Observatory for Study Climate (MOSAiC), drift with sea ice from October 2019 September 2020. An international team designed implemented program characterize system unprecedented detail, seafloor air-sea ice-ocean interface,...
Abstract A major surface circulation feature of the Arctic Ocean is Transpolar Drift (TPD), a current that transports river‐influenced shelf water from Laptev and East Siberian Seas toward center basin Fram Strait. In 2015, international GEOTRACES program included high‐resolution pan‐Arctic survey carbon, nutrients, suite trace elements isotopes (TEIs). The cruises bisected TPD at two locations in central basin, which were defined by maxima meteoric dissolved organic carbon concentrations...
At the Surface Heat Budget of Arctic Ocean (SHEBA) program's field site in northern Chukchi Sea, snow and ice meltwater flow was found to have a strong impact on heat mass balance sea during summer 1998. Pathways rates transport were derived from tracer studies (H 2 18 O, 7 Be, release fluorescent dyes), complemented by situ sea‐ice permeability measurements. It shown that between supply at surface (averaging 3.5 10.5 mm d −1 ) (between <10 −11 >10 −9 m determines retention pooling...
Research involving a yearlong drift with the ice pack in Arctic Ocean witnessed surprisingly thin at start and even thinner end. Also, extent of open water during summer 1998 Beaufort Chukchi Seas was greatest past 2 decades. As is melting from under your feet there an understandable tendency to blame global warming. But project, known as Surface Heat Budget (SHEBA), though motivated by climate change, not designed detect Definitive change pronouncements can be made based on single experiment.
The largest flux of terrigenous organic carbon into the ocean occurs in dissolved form by way rivers. fate this material is enigmatic; there are numerous reports conservative behavior over continental shelves, but only knowledge we have about removal that it on long unknown time scales deep ocean. To investigate process, evaluated concentration gradients Beaufort Gyre western Arctic Ocean, which allowed us to observe carbon's slow degradation. Using isotopic tracers water-mass age,...
In September 2004 a detailed physical and chemical survey was conducted on an anticyclonic, cold‐core eddy located seaward of the Chukchi Shelf in western Arctic Ocean. The had diameter ∼16 km centered at depth ∼160 m between 1000 1500 isobaths over continental slope. water core (total volume 25 3 ) Pacific origin, contained elevated concentrations nutrients, organic carbon, suspended particles. feature, which likely formed from boundary current along edge Shelf, provides mechanism for...
Abstract Ocean acidification is projected to lower the Ω ar of reefal waters by 0.3–0.4 units end century, making it more difficult for calcifying organisms secrete calcium carbonate while at same time environment favorable abiotic and biotic dissolution framework. There great interest in being able project point when coral reefs will cross tipping between net depositional erosional terms their budgets. Periodic situ assessments balance production that spans seasonal scales may prove useful...
Deposition of continental mineral aerosols (dust) in the Eastern Tropical North Atlantic Ocean, between coast Africa and Mid-Atlantic Ridge, was estimated using several strategies based on measurement aerosols, trace metals dissolved seawater, particulate material filtered from water column, particles collected by sediment traps sediments. Most data used this synthesis involve samples during US GEOTRACES expeditions 2010 2011, although some results literature are also used. Dust deposition...
Research Article| January 01, 1998 Warm springs discovered on 3.5 Ma oceanic crust, eastern flank of the Juan de Fuca Ridge M. J. Mottl; Mottl 1School Ocean and Earth Science Technology, University Hawaii, Honolulu, Hawaii 96822 Search for other works by this author on: GSW Google Scholar G. Wheat; Wheat 2Institute Sciences, Alaska, Fairbanks, Alaska 99775 E. Baker; Baker 3Pacific Marine Environmental Laboratory, National Oceanic Atmospheric Administration, 7600 Sand Point Way, Seattle,...
Abstract The distributions of iodate and iodide were measured along the GEOTRACES GP15 meridional transect at 152°W from shelf Alaska to Papeete, Tahiti. included oxygenated waters near Alaska, full water column in central basin North Pacific Basin, upper spanning across seasonally mixed regimes north, oligotrophic gyre, equatorial upwelling. Iodide concentrations are highest permanently stratified tropical layers, which reflect accumulation due light‐dependent biological processes, decline...
Three active hydrothermal vents forming sulfide mounds and chimneys (Monolith, Fountain, Pipe Organ) more widely distributed inactive are spatially related to a system of discontinuous fissures young sheet flow lavas at the northern Cleft segment, Juan de Fuca Ridge. The formation zoned tubular Curich (type I) on Monolith mound is focused high‐temperature (to 328°C) fluid. Bulbous II or “beehives”) Fountain products diffuse 315°C) discharge. A broader zone vigorous mixing between fluid...
High rates of primary production and fast sinking lead to the deposition phytodetritus highly reactive organic matter sediments central equatorial Pacific. These substances are responsible for driving important chemical fluxes fueling benthic organisms. Chloropigments have proven useful as tracers similar carbon components in lacustrine nearshore marine sediments. In this study we investigate degradation chlorophyll-a pheopigments-a at four abyssal sites on JGOFS Pacific transect along 140°W...
Observations during the Coastal Transition Zone (CTZ) experiment in summer 1988 reveal presence of deep phytoplankton layers a coastal upwelling system. The occur throughout CTZ study area, including strong baroclinic jet which was present over period experiment. On basis variety bio‐optical, hydrographic, and geochemical indicators, it is concluded that water masses associated with result from subduction processes. Criteria are developed for identification subducted based on beam...