Contributors | Affiliation | Role |
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Anderson, Robert F. | Lamont-Doherty Earth Observatory (LDEO) | Principal Investigator |
Chandler, Cynthia L. | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
Radionuclides, moored sediment trap samples
PI: Bob Anderson of: Lamont-Doherty Earth Observatory dataset: Radionuclides, moored sediment trap samples
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rad_sed_trap.csv (Comma Separated Values (.csv), 3.13 KB) MD5:a4089aade676a81d571ff20229139dcb Primary data file for dataset ID 2607 |
Parameter | Description | Units |
sta_name | station name | |
lat_n | latitude, nominal, minus means South | degrees |
lon_n | longitude, nominal, minus means West | degrees |
depth_trap | depth of sediment trap | meters |
cup | cup number(s) from which sample was collected | |
date_begin | date sampling begins, as YYYYMMDD | |
date_end | date sampling ends, as YYYYMMDD | |
Pb210_part_lt1mm | lead-210, particulate | dpm/gram |
Pb210_err | lead-210 error, plus/minus 1 sigma | dpm/gram |
Th230_part_lt1mm | thorium-230, particulate | dpm/gram |
Th230_err | thorium-230 error, plus/minus 1 sigma | dpm/gram |
Pa231_part_lt1mm | protactinium-231 particulate | dpm/gram |
Pa231_err | protactinium-231 error, plus/minus 1 sigma | dpm/gram |
Be10_part_lt1mm | beryllium-10, particulate | atoms/gram |
Be10_err | beryllium-10 error, plus/minus 1 sigma | atoms/gram |
Dataset-specific Instrument Name | Accelerator Mass Spectrometer |
Generic Instrument Name | Accelerator Mass Spectrometer |
Generic Instrument Description | An AMS measures "long-lived radionuclides that occur naturally in our environment. AMS uses a particle accelerator in conjunction with ion sources, large magnets, and detectors to separate out interferences and count single atoms in the presence of 1x1015 (a thousand million million) stable atoms, measuring the mass-to-charge ratio of the products of sample molecule disassociation, atom ionization and ion acceleration." AMS permits ultra low-level measurement of compound concentrations and isotope ratios that traditional alpha-spectrometry cannot provide. More from Purdue University: http://www.physics.purdue.edu/primelab/introduction/ams.html |
Dataset-specific Instrument Name | Sediment Trap |
Generic Instrument Name | Sediment Trap |
Generic Instrument Description | Sediment traps are specially designed containers deployed in the water column for periods of time to collect particles from the water column falling toward the sea floor. In general a sediment trap has a jar at the bottom to collect the sample and a broad funnel-shaped opening at the top with baffles to keep out very large objects and help prevent the funnel from clogging. This designation is used when the specific type of sediment trap was not specified by the contributing investigator. |
Website | |
Platform | JGOFS Sediment Trap |
Start Date | 1992-01-12 |
End Date | 1992-02-08 |
Description | Sediment Trap Deployments at 140°W that relate to seven locations between 9°N and 12°S Processing Description January 8, 2002 Bob Anderson Lamont-Doherty Earth Observatory It was necessary to composite individual time-series sediment trap samples to obtain sufficient material for radionuclide analysis. In the spreadsheet we indicate the cup numbers, as presented by Honjo et al., 1995, used to prepare each composite sample. The EqPac sediment trap samples were analyzed by isotope dilution alpha spectrometry for the U- and Th-series. The Th-232 content of the trap samples was so low that we were unable to resolve the Th-232 peak above the tail of the Th-230 peak, so no Th-232 data are reported. Be-10 was measured by accelerator mass spectrometry. The reference that best described the methods followed for measuring Th, Pa and 10Be in sediment trap samples is: Y. Lao, R.F. Anderson, W.S. Broecker, H.J. Hofmann and W. Wolfli, Particulate fluxes of 230Th, 231Pa, and 10Be in the Northeastern Pacific Ocean, Geochimica Cosmochimica Acta 57(1), 205-217, 1993. The reference that best described the method followed for measuring Pb-210 in sediment trap samples is: Anderson, R. F., S. L. Schiff and R. H. Hesslein (1987). Determining sediment accumulation and mixing rates using 210Pb, 137Cs, and other tracers: problems due to post depositional mobility or coring artifacts. Can. J. Fish. Aquat. Sci., Vol. 44, Supplement No. 1: 231-250. |
The U.S. EqPac process study consisted of repeat meridional sections (12°N -12°S) across the equator in the central and eastern equatorial Pacific from 95°W to 170°W during 1992. The major scientific program was focused at 140° W consisting of two meridional surveys, two equatorial surveys, and a benthic survey aboard the R/V Thomas Thompson. Long-term deployments of current meter and sediment trap arrays augmented the survey cruises. NOAA conducted boreal spring and fall sections east and west of 140°W from the R/V Baldridge and R/V Discoverer. Meteorological and sea surface observations were obtained from NOAA's in place TOGA-TAO buoy network.
The scientific objectives of this study were to determine the fluxes of carbon and related elements, and the processes controlling these fluxes between the Equatorial Pacific euphotic zone and the atmosphere and deep ocean. A broad overview of the program at the 140°W site is given by Murray et al. (Oceanography, 5: 134-142, 1992). A full description of the Equatorial Pacific Process Study, including the international context and the scientific results, appears in a series of Deep-Sea Research Part II special volumes:
Topical Studies in Oceanography, A U.S. JGOFS Process Study in the Equatorial Pacific (1995), Deep-Sea Research Part II, Volume 42, No. 2/3.
Topical Studies in Oceanography, A U.S. JGOFS Process Study in the Equatorial Pacific. Part 2 (1996), Deep-Sea Research Part II, Volume 43, No. 4/6.
Topical Studies in Oceanography, A U.S. JGOFS Process Study in the Equatorial Pacific (1997), Deep-Sea Research Part II, Volume 44, No. 9/10.
Topical Studies in Oceanography, The Equatorial Pacific JGOFS Synthesis (2002), Deep-Sea Research Part II, Volume 49, Nos. 13/14.
The United States Joint Global Ocean Flux Study was a national component of international JGOFS and an integral part of global climate change research.
The U.S. launched the Joint Global Ocean Flux Study (JGOFS) in the late 1980s to study the ocean carbon cycle. An ambitious goal was set to understand the controls on the concentrations and fluxes of carbon and associated nutrients in the ocean. A new field of ocean biogeochemistry emerged with an emphasis on quality measurements of carbon system parameters and interdisciplinary field studies of the biological, chemical and physical process which control the ocean carbon cycle. As we studied ocean biogeochemistry, we learned that our simple views of carbon uptake and transport were severely limited, and a new "wave" of ocean science was born. U.S. JGOFS has been supported primarily by the U.S. National Science Foundation in collaboration with the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, the Department of Energy and the Office of Naval Research. U.S. JGOFS, ended in 2005 with the conclusion of the Synthesis and Modeling Project (SMP).