Dataset: Thorium Summary

Name: Thorium isotope data summaries from R/V Yuzhmorgeologiya, RVIB Nathaniel B. Palmer AMLR2006-Leg1, NBP0606 in the Southern Ocean from January to August 2006 (Ant2006 project, BWZ project)
Published: 2009-03-11
Keywords: oceans

Cite This Dataset

Spatial Extent: N:-59.9964 E:-52.8745 S:-63.2335 W:-62.9966

Project:

Blue Water Zone (BWZ)

Plankton Community Structure and Iron Distribution in the Southern Drake Passage and Scotia Sea (Ant2006)

Principal Investigator:

Matthew A. Charette (Woods Hole Oceanographic Institution, WHOI)

Co-Principal Investigator:

Dr Henrieta Dulaiova (University of Hawaiʻi at Mānoa, SOEST)

BCO-DMO Data Manager:

Stephen R. Gegg (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

11 March 2009

Version Date:

2009-03-11

Validated:

Yes

Current State:

Final no updates expected

Thorium isotope data summaries from R/V Yuzhmorgeologiya, RVIB Nathaniel B. Palmer AMLR2006-Leg1, NBP0606 in the Southern Ocean from January to August 2006 (Ant2006 project, BWZ project)

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Description

Thorium isotope data summaries from AMLR and NBP cruises to the Antarctic in 2006

Particulate organic Carbon (POC) flux was determined through measuring Thorium (234Th) reported in dpm/kg .

Cruises

AMLR (Antarctic Marine Living Resources) R/V Yuzhmorgeologiya Jan2006:
The research program was focused in the southern Drake Passage
along the Shackelton Shelf located near the Bransfield Strait.
Samples were obtained from the R/V Yuzhmorgeologiya and inflatables
that were taken to island locations.
Lat/Lon Bounding Box
-62.2538Lat, -62.9966Lon
-63.2335Lat, -59.0332Lon
-59.9964Lat, -55.7612Lon
-61.4995Lat, -53.9996Lon

NBP (Nathaniel B. Palmer) R/V Nathaniel B. Palmer July2006:
The research was conducted in the same region of the Drake Passage as the AMLR cruise.
Samples were obtained aboard the R/V Nathaniel B. Palmer
Lat/Lon bounding box
-60.4991Lat, -58.5613Lon
-62.3599Lat, -58.0392Lon
-60.2783Lat, -57.4509Lon
-61.2683Lat, -54.2852Lon

Associated Publications

Brzezinski, M.A., Nelson, D.M., Franck, V.M. and Sigmon, D.E., 2001. "Silicon dynamics within an intense open-ocean diatom bloom in the pacific sector of the southern ocean." Deep-Sea Research Part II 48, pp. 3997-4018

Michiel Rutgers van der Loeff, Manmohan M. Sarin, Mark Baskaran, Claudia Benitez-Nelson, Ken O. Buesseler, Matt Charette, Minhan Dai, Örjan Gustafsson, Pere Masque, Paul J. Morris, Kent Orlandini, Alessia Rodriguez y Baena, Nicolas Savoye, Sabine Schmidt, Robert Turnewitsch, Ingrid Vöge, James T. Waples. "A review of present techniques and methodological advances in analyzing 234Th in aquatic systems" Marine Chemistry, Volume 100, Issues 3-4, 1 August 2006, Pages 190-212

Pike, S.M., K.O. Buesseler, J. Andrews and N. Savoye, 2005. "Quantification of 234Th recovery in small volume sea water samples by inductively coupled plasma mass spectrometry." (PDF) Journal of Radioanalytical and Nuclear Chemistry, 263(2): 355-360.

Willard S. Moore and Ralph Arnold (1996). "Measurement of 223Ra and 224Ra in coastal waters using a delayed coincidence counter." Journal of Geophysical Research, vol. 101, no. c1, pages 1321-1329, January 15, 1996.

Methods & Sampling

Sampling and Analytical Methodology

Particle sinking rates were determined using the 4 liter measurement of 234Th (Pike et al., 2005). Samples were collected from hydrocasts from a shipboard CTD. The unfiltered 4-liter samples were immediately acidified to pH ~1.5 using concentrated Nitric acid. Samples were shaken vigorously and 230Th added as a yield monitor. The samples were shaken again and allowed to equilibrate for 8 hours. Concentrated NH4OH was subsequently added to each sample to adjust the pH to 8. Extraction of thorium from seawater was then accomplished by co-precipitation via a MnO2 precipitate onto a 25-mm-diameter QMA filter. The filtered samples were air dried and counted on a RISO beta detector (Rutgers van der Loeff et al., 2006). All samples were counted for at least 24 hours or until the counting error was < 3%. Samples were recounted after >150 days (~6 half lives) to determine the sample background. Detector calibration was confirmed with 3000m deep water sample.

Particulate carbon was collected through a McLane WTS-LV in-situ pump and filtered through a 142mm GFF filter. 22mm subsamples were collected, dried and transported back to the WHOI laboratory for CHN analysis on the Flash EA1112. The samples were pelletized in ultra clean tin capsules, combusted at 900oC, separated in a gas chromatographic column, and measured through a thermal conductivity detector. The CHN analyzer was calibrated by using an acetanilide standard. A second subsample was taken and analyzed for biogenic silica (Brzezinski et al 2001). Sodium Hydroxide was added to the filter and heated to 95oC for 45minutes. It was placed on ice and neutralized with hydrochloric acid. After centrifuging, the supernatant is then analyzed for silicate on a Lachat Quickchem 8000.

Data Processing Description

Data Processing

CHN: Linear regression of standards is used to determine the carbon content of the sample

Th: Thorium is measured using the Riso betacounters. Results published include removal ofsample background, detector efficiency correction, correction of radioactive decay, and chemistry efficiency through analysis of tracer (230Th).

Modifications to original data made to conform to BCO-DMO database convention

Cruise_ID added
Spaces in Sample_ID replaced with dashes for consistency with Radium summary data empty cells filled with "nd" (no data)
Latitude/Longitude headers converted to lat/lon
date reformatted to YYYYMMDD
time reformatted to HHMM
decimal data values padded to consistent decimal places
spaces, minus signs, and "<"'s replaced with underscores or text in misc data headers
POC/PON used in place of Part Organic Carbon/Nitrogen in headers
"No Sample" values replaced with "nd" in Sample_Ids FA-494, FA-495
"Surface" values in Depth data replaced with "1"

Data Files

File
Thorium_Summary.csv (Comma Separated Values (.csv), 42.98 KB) MD5:80d154eaca96e4f6349e46054233c7a3 Primary data file for dataset ID 3086

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Antarctic Sciences	ANT-0443869

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
AMLR2006-Leg1	Yuzhmo AMLR (January 2006)	2006-01-11	R/V Yuzhmorgeologiya	Adam Jenkins (Chief Scientist)	data info
NBP0606	R/V Palmer NBP (July 2006)	2006-07-01	RVIB Nathaniel B. Palmer	B. Gregory Mitchell (Chief Scientist)	data info

Instruments

CTD - profiler

Supplied Name: Conductivity, Temperature, Depth

Supplied Description:

Shipboard CTD

Instrument Type

Generic Name: CTD - profiler

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/130/

Generic Description:

The Conductivity, Temperature, Depth (CTD) unit is an integrated instrument package designed to measure the conductivity, temperature, and pressure (depth) of the water column. The instrument is lowered via cable through the water column. It permits scientists to observe the physical properties in real-time via a conducting cable, which is typically connected to a CTD to a deck unit and computer on a ship. The CTD is often configured with additional optional sensors including fluorometers, transmissometers and/or radiometers. It is often combined with a Rosette of water sampling bottles (e.g. Niskin, GO-FLO) for collecting discrete water samples during the cast.

This term applies to profiling CTDs. For fixed CTDs, see https://www.bco-dmo.org/instrument/869934.

McLane Large Volume Pumping System WTS-LV

Supplied Name: Large Volume Pumping System -WTS-LV

Supplied Description:

McLane WTS-LV Large Volume, High Accuracy, Oceanographic Sampling Pump

Instrument Type

Generic Name: McLane Large Volume Pumping System WTS-LV

Acronym: WTS-LV

Generic Description:

The WTS-LV is a Water Transfer System (WTS) Large Volume (LV) pumping instrument designed and manufactured by McLane Research Labs (Falmouth, MA, USA). It is a large-volume, single-event sampler that collects suspended and dissolved particulate samples in situ.

Ambient water is drawn through a modular filter holder onto a 142-millimeter (mm) membrane without passing through the pump. The standard two-tier filter holder provides prefiltering and size fractioning. Collection targets include chlorophyll maximum, particulate trace metals, and phytoplankton. It features different flow rates and filter porosity to support a range of specimen collection. Sampling can be programmed to start at a scheduled time or begin with a countdown delay. It also features a dynamic pump speed algorithm that adjusts flow to protect the sample as material accumulates on the filter. Several pump options range from 0.5 to 30 liters per minute, with a max volume of 2,500 to 36,000 liters depending on the pump and battery pack used. The standard model is depth rated to 5,500 meters, with a deeper 7,000-meter option available. The operating temperature is -4 to 35 degrees Celsius.

The WTS-LV is available in four different configurations: Standard, Upright, Bore Hole, and Dual Filter Sampler. The high-capacity upright WTS-LV model provides three times the battery life of the standard model. The Bore-Hole WTS-LV is designed to fit through a narrow opening such as a 30-centimeter borehole. The dual filter WTS-LV features two vertical intake 142 mm filter holders to allow simultaneous filtering using two different porosities.

Pump - Surface Underway Ship Intake

Supplied Name: Pump5

Supplied Description:

Ship's clean water intake pump (surface sample)

Instrument Type

Generic Name: Pump - Surface Underway Ship Intake

Acronym: Pump-Ship Intake

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/31/

Generic Description:

The 'Pump-underway ship intake' system indicates that samples are from the ship's clean water intake pump. This is essentially a surface water sample from a source of uncontaminated near-surface (commonly 3 to 7 m) seawater that can be pumped continuously to shipboard laboratories on research vessels. There is typically a temperature sensor near the intake (known as the hull temperature) to provide measurements that are as close as possible to the ambient water temperature. The flow from the supply is typically directed through continuously logged sensors such as a thermosalinograph and a fluorometer. Water samples are often collected from the underway supply that may also be referred to as the non-toxic supply. Ideally the data contributor has specified the depth in the ship's hull at which the pump is mounted.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
Cruise_ID	Antarctica 2006 Cruise Id	text	cruise_id
Sample_ID	Antarctica 2006 Sample Id	text	sample
Station_ID	Antarctica 2006 Station Id	text	station
date	Date of sample collection (GMT)	YYYYMMDD	date
time	Time of sample collection (GMT)	HHMM	time
lat	Latitude position of sample. Decimal degs (South is negative).	decimal degrees	lat
lon	Longitude position of sample. Decimal degs (West is negative)	decimal degrees	lon
depth	Depth of sample	meters	depth
cast	CTD cast number	integer	cast
bottle	CTD bottle number	integer	bottle
Total_Thorium	Total thorium dpm at collection	dpm/kg	Th234_tot
Thorium_net_err	Total_Thorium net err	+/- dpm	no_bcodmo_term
POC_gt54_micron	Particulate Organic Carbon (>54microns)	uM/Liter	POC
PON_gt54_micron	Particulate Organic Nitrogen (>54microns)	uM/Liter	PON
POC_1_to_54_micron	Particulate Organic Carbon (1-54microns)	uM/Liter	POC
PON_1_to_54_micron	Particulate Organic Nitrogen (1-54microns)	uM/Liter	PON
BioAvail_Silicate	Biological Available Silicate	uM/Liter	Silicate

Status message

Database

Contribute Data

Dataset: Thorium Summary

Thorium isotope data summaries from AMLR and NBP cruises to the Antarctic in 2006

Cruises

Associated Publications

Sampling and Analytical Methodology

Data Processing

Modifications to original data made to conform to BCO-DMO database convention