Dataset: Palmer Station Thorium

Name: Total water column Thorium-234 measurements collected during the 2012-2013 Palmer Field Season (WAP Carbon export project)
Published: 2022-08-02
Keywords: oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.881459.1

Spatial Extent: N:-64.7795 E:-64.0405 S:-64.815 W:-64.0725

Western Antarctic Peninsula near Anvers Island

Temporal Extent: 2012-10-31 - 2013-03-25

Project:

Quantifying Processes Driving Interannual Variability in the Biological Carbon Pump in the Western Antarctic Peninsula (WAP Carbon export)

Principal Investigator:

Michael R. Stukel (Florida State University EOAS, FSU - EOAS)

BCO-DMO Data Manager:

Sawyer Newman (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2022-08-02

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Total water column Thorium-234 measurements collected during the 2012-2013 Palmer Field Season (WAP Carbon export project)

Abstract:

Total water-column Th-234 measurements collected during the 2012-2013 field season of the Palmer LTER program near Anvers Island in the Western Antarctic Peninsula. 238U-234Th disequilibrium is used as a proxy for sinking particle flux out of the upper ocean. Vertical profiles of 234Th were measured using standard small-volume techniques approximately weekly. Measurements typically spanned from the surface to a depth of 100 m.

Expand/Collapse All

Archival Copy

Version Date	Archive	Persistent Identifier (PID)	Date PID Issued
2022-08-02	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.881459.1	2024-09-23

Methods & Sampling

Salinity and density were measured using a CTD. 4-L Samples for total water-column ²³⁴Th activity were collected using Go-Flo bottles at 7 depths from the surface to 100 m. Sample volume was determined gravimetrically and then samples were acidified to a pH < 2 with nitric acid and a Th-230 tracer spike was added. Samples were shaken and allowed to equilibrate for 4 – 9 hours. Samples were then re-basified with ammonium hydroxide to a pH of 8 – 9, shaken, and allowed to equilibrate for >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. 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 shipped to the Woods Hole Analytical laboratory for analysis of the Th-229:Th-230 ratio, which was used to calculate the initial precipitation and filtration yield of Th-234. For additional details, see Stukel et al. (2015) and Stukel et al. (2022).

Problems/Issues

Blank values in the dataset indicate that the samples were lost and/or the data is otherwise unavailable.

BCO-DMO Processing

- Spaces removed from column names and replaced with underscores ("_")
- Row containing units removed from the data file
- 'NaN' values in the data file were replaced with blank values ("")
- Collection_Date date format converted from %m-%d-%y to %Y-%m-%d
- Date format converted from local time at Palmer Station (UTC-3) to UTC

Data Files

File
881459_v1_palmer_station_thorium.csv (Comma Separated Values (.csv), 26.53 KB) MD5:3e210840fc6532320ff757a0ba286661 Primary data file for dataset ID 881459, version 1

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Office of Polar Programs (formerly NSF PLR)	OPP-1951090
NSF Division of Ocean Sciences	OCE-1756610
NSF Office of Polar Programs (formerly NSF PLR)	OPP-1340886
NSF Office of Polar Programs (formerly NSF PLR)	OPP-1440435

Deployments

None available yet

Instruments

GM multicounter

Supplied Name: Riso low-level GM beta multi-counter

Supplied Description:

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.

Instrument Type

Generic Name: GM multicounter

Generic Description:

A gas flow multicounter (GM multicounter) is used for counting low-level beta doses. GM multicounters can be used for gas proportional counting of 32Si to 32P. For more information about GM multicounter usage see Krause et. al. 2011.

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
Station	Palmer LTER station name from which sample was collected.	unitless	station
Latitude	Station Latitude in decimal degrees; a positive value indicates a Northern coordinate.	decimal degrees	lat
Longitude	Station Longitude in decimal degrees; a positive value indicates an Eastern coordinate.	decimal degrees	lon
Collection_Date_and_Time	Date and time of collection. Format: %Y-%m-%d	unitless	date
Depth	Depth at which sample was collected.	meter (m)	depth
Salinity	Salinity.	PSU	sal
Density	Density.	kilogram per liter (kg/L^-1)	density
Th234	Total water-column Thorium isotope 234Th.	decays per minute per liter (dpm/L^-1)	Th234
Uncertainty	Uncertainty in thorium isotope 234Th.	decays per minute per liter (dpm/L^-1)	Th234
Deficiency	238Uranium-234Thorium deficiency.	decays per minute per liter (dpm/L^-1)	radioactive_isotope_err
Def_Uncertainty	Uncertainty in deficiency.	decays per minute per liter (dpm/L^-1)	radioactive_isotope_err

Status message

Database

Contribute Data

Dataset: Palmer Station Thorium