Dataset: Thorium-234 from SalpPOOP cruise
Deployment: TAN1810

View Data: For data, See Dataset Metadata Page: https://www.bco-dmo.org/dataset/883989

Principal Investigator:

Michael R. Stukel (Florida State University, FSU)

Co-Principal Investigator:

Moira Decima (University of California-San Diego Scripps, UCSD-SIO)

Thomas Kelly (University of Alaska Fairbanks, UAF)

BCO-DMO Data Manager:

Taylor Heyl (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Collaborative Research: Quantifying trophic roles and food web ecology of salp blooms of the Chatham Rise (Salp Food Web Ecology)

Version:

Deployment Synonyms:

SalpPOOP

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Description

Methods & Sampling

Dataset acquisition description

This dataset represents water column Thorium-234 data from the SalpPOOP, Tangaroa Cruise 1810 (aka SalpPOOP cruise). Salinity and density were measured using a CTD. 4-liter (L) samples for total water-column 234Th activity were collected using CTD bottles at approximately 12 depths from the surface to approximately 300 meters. Samples were acidified with nitric acid to a pH < 2, and a Th-230 tracer spike was added. Samples were shaken and allowed to equilibrate for 4 to 9 hours. Samples were then re-basified with ammonium hydroxide to a pH of 8-9, shaken, and allowed to equilibrate for more than 8 hours. Samples were then vacuum filtered at high vacuum pressure through a quartz (QMA) filter. Filters were mounted in RISO planchets and counted on a RISO low-level beta multi-counter at Palmer Station, Antarctica. Following a background count > 6 months later, samples were dissolved in 8M nitric acid / 10% hydrogen peroxide solution and a Th-229 tracer spike was added. Samples were then analyzed on an ICP-MS to quantify the Th-229:Th-230 ratio, which was used to calculate the initial precipitation and filtration yield of Th-234. Protocols from Pike et al. (2005) were followed.

For additional sampling details see Decima et al. (in review, Nat. Comm.).

Data Processing Description

Dataset Processing Description

BCO-DMO Processing description:
- Converted collection date column and added column for ISO date format (YYYY-MM-DDThh:mmZ)
- Adjusted field/parameter names to comply with BCO-DMO naming conventions
- Added a conventional header with dataset name, PI names, version date
- Added a column for Cruise ID
- Added columns for “Latitude” and “Longitude”
- Rounded columns: “Latitude”, “Longitude”, “Depth”, “U238_activitiy”, “Th234_activity”, and “Th234_measurement_uncertainty” to 3 decimal places (or to the thousandth place)

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1756465	NSF Division of Ocean Sciences
OCE-1756610	NSF Division of Ocean Sciences

Instruments

CTD - fixed

Supplied Name:

Supplied Description:

Instrument Type

Generic Name: CTD - fixed

Generic Description:

A reusable instrument that always simultaneously measures conductivity and temperature (for salinity) and pressure (for depth).

This term applies to CTDs that are fixed and do not measure by profiling through the water column. For profiling CTDs, see https://www.bco-dmo.org/instrument/417.

Inductively Coupled Plasma Mass Spectrometer

Supplied Name: ICP-MS (Inductively coupled plasma mass spectrometer)

Supplied Description:

Instrument Type

Generic Name: Inductively Coupled Plasma Mass Spectrometer

Acronym: ICP Mass Spec

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB15/

Generic Description:

An ICP Mass Spec is an instrument that passes nebulized samples into an inductively-coupled gas plasma (8-10000 K) where they are atomized and ionized. Ions of specific mass-to-charge ratios are quantified in a quadrupole mass spectrometer.

Riso Laboratory Anti-coincidence Beta Counters

Supplied Name: RISO low-level beta multi-counter

Supplied Description:

Instrument Type

Generic Name: Riso Laboratory Anti-coincidence Beta Counters

Acronym: Riso Beta Counter

Generic Description:

Low-level beta detectors manufactured by Riso (now Nutech) in Denmark. These instruments accept samples that can be mounted on a 25mm filter holder. These detectors have very low backgrounds, 0.17 counts per minute, and can have counting efficiencies as high as 55%.

Typically used in laboratory analyses. Designed to measure low levels of beta particle emission. The systems work on the principle of anticoincidence.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
Cruise_ID	Cruise Identification	unitless	cruise_id
Collection_Datetime	Local date of collection (New Zealand ST) in format: YYYY-MM-DDThh:mmZ	unitless	DateTime
ISO_DateTime_UTC	Date of collection in ISO 8601 format	unitless	ISO_DateTime_UTC
Cast_Number	Cast number on the cruise	unitless	cast
Cycle	Lagrangian experiment number	unitless	exp_id
Latitude	Latitude of sample collection North	decimal degrees	lat
Longitude	Longitude of sample collection East (West is negative)	decimal degrees	lon
Depth	Depth of sample collection	meters	depth
U238_activity	Activity of Uranium-238	decays per minute per liter	U238_in_sw
Th234_activity	Activity of Thorium-234	decays per minute per liter	Th234
Th234_measurement_uncertainty	Uncertainty in Th234 activity	decays per minute per liter	Th234_err

Database

Contribute Data

Dataset: Thorium-234 from SalpPOOP cruise
Deployment: TAN1810

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Thorium-234 from SalpPOOP cruiseDeployment: TAN1810

Dataset acquisition description

Dataset Processing Description

Dataset: Thorium-234 from SalpPOOP cruise
Deployment: TAN1810