Dataset: Thorium-234 from SalpPOOP cruise

Name: Thorium-234 data from SalpPOOP cruise on the R/V Tangaroa to the Chatham Rise (subtropical and subantarctic waters) in October and November 2018
Published: 2022-12-16
Keywords: thorium-234, uranium-thorium disequilibrium, Carbon Export, salps, sinking particles, oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.883989.1

Spatial Extent: N:-42.7082 E:-179.849167 S:-45.5503 W:179.851

Temporal Extent: 2018-10-24 - 2018-11-17

Project:

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

Principal Investigator:

Michael Stukel (Florida State University, FSU)

Co-Principal Investigator:

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

Thomas Kelly (University of Alaska Fairbanks, UAF)

BCO-DMO Data Manager:

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

Version:

Version Date:

2022-12-16

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Thorium-234 data from SalpPOOP cruise on the R/V Tangaroa to the Chatham Rise (subtropical and subantarctic waters) in October and November 2018

Abstract:

This dataset represents Thorium-234 data from samples in the water column at the Chatham Rise (subtropical and subantarctic waters) on the Tangaroa Cruise 1810 (aka SalpPOOP cruise) in October and November 2018.

Expand/Collapse All

Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2022-12-16	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.883989.1	2022-12-16

Methods & Sampling

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

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)

Data Files

File
thorium234.csv (Comma Separated Values (.csv), 11.44 KB) MD5:9e5deea1f7386ace969290858c093eb7 Primary data file for dataset ID 883989

More Information about this dataset

Funding Sources

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

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
TAN1810	SalpPOOP	2018-10-23	R/V Tangaroa	Moira Decima (Chief Scientist)	data info

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%.

Parameters

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

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 Format: %Y-%m-%dT%H:%M	unitless	DateTime
ISO_DateTime_UTC	Date of collection in ISO 8601 format Format: %Y-%m-%dT%H:%M	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
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

Status message

Database

Contribute Data

Dataset: Thorium-234 from SalpPOOP cruise