Dataset: Gulf of Mexico bottom water analysis

Name: Chemical analysis from sediment core bottom water samples collected in the northern Gulf of Mexico, May 2017
Published: 2018-08-06
Keywords: oceans

Cite This Dataset

DOI:10.1575/1912/bco-dmo.745932.1

Spatial Extent: N:29.907 E:-84.456 S:29.853 W:-84.552

Temporal Extent: 2017-07-11 - 2017-07-20

Project:

Toward an Improved Understanding of Blue Carbon: The Role of Seagrasses in Sequestering CO2 (Seagrass Blue Carbon)

Principal Investigator:

David J. Burdige (Old Dominion University, ODU)

Co-Principal Investigator:

Matthew H. Long (Woods Hole Oceanographic Institution, WHOI)

Richard C. Zimmerman (Old Dominion University, ODU)

BCO-DMO Data Manager:

Nancy Copley (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2018-08-06

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Chemical analysis from sediment core bottom water samples collected in the northern Gulf of Mexico, May 2017

Abstract:

This dataset includes results of analysis on sediment core bottom water samples collected from the northern Gulf of Mexico in May 2017 - initial pH, alkalinity, sulfate, DIC, and DOC.

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Archival Copy

Version Date	Archive	Persistent Identifier	Date Assigned
2018-08-06	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.1575/1912/bco-dmo.745932.1	2019-03-20

Description

This dataset includes results of analysis on sediment core bottom water samples collected from the northern Gulf of Mexico in May 2017 - initial pH, alkalinity, sulfate, DIC, and DOC.

Methods & Sampling

Sediment cores were collected by divers, sealed in the field with rubber stoppers and returned to the lab for processing. Pore waters were collected by inserting rhizon samplers (Seeberg-Elverfeldt et al., 2005) through pre-drilled holes in the core tubes. Samples were collected in gas-tight glass syringes and filtered through 0.45 µm nylon filters into storage vials. Alkalinity samples were titrated within 12hr of collection; other samples were returned to the lab for analysis, using techniques routinely used in my lab: alkalinity and initial pH - Hu and Burdige (2008); sulfate, DIC, ammonium and DOC - Burdige and Komada (2011), Komada et al. (2016); sulfide - Cline (1969), Abdulla et al. (in prep.).

Alkalinity and initial pH were determined by Gran Titration using a Metrohm automatic titrator (model 785 DMP Titrino) combined with a Cole-Parmer pH electrode, calibrated using pH 4.00, 7.00 and 10.00 NIST-traceable buffers (Hu and Burdige, 2008).

Sulfate was determined by ion chromatography and conductivity detection with a Thermo-Fisher Dionex ICS-5000 ion chromatograph.

DOC was determined by high temperature combustion using a Shimadzu TOC-V total carbon analyzer (Burdige and Komada, 2011; Komada et al. 2016).

DIC were determined by FIA analysis using a home-built system consisting of a Rainin Rabbit peristaltic pump and a Dionex CDM-II conductivity detector (Hall and Aller, 1992; Lustwerk and Burdige, 1995).

Note: "ns" stands for "samples not collected for this analysis".

Data Processing Description

BCO-DMO Processing Notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions
- added columns for site, lat, and lon
- reformatted collection date and time from m/d/yyyy H:MM to YYYY-MM-DDTHH:MM:SS (ISO 8601:2004E)

Data Files

File
GOM_2017_bottom_water.csv (Comma Separated Values (.csv), 1.18 KB) MD5:c088f4cf4b294f85927f8fece35dc576 Primary data file for dataset ID 745932

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1633951
NSF Division of Ocean Sciences	OCE-1635403

Deployments

None available yet

Instruments

Automatic titrator

Supplied Name:

Supplied Description:

Used to measure alkalinity

Instrument Type

Generic Name: Automatic titrator

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB12/

Generic Description:

Instruments that incrementally add quantified aliquots of a reagent to a sample until the end-point of a chemical reaction is reached.

Automatic titrator

Supplied Name: Metrohm automatic titrator (model 785 DMP Titrino)

Supplied Description:

Used to measure alkalinity and initial pH.

Instrument Type

Generic Name: Automatic titrator

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB12/

Generic Description:

Instruments that incrementally add quantified aliquots of a reagent to a sample until the end-point of a chemical reaction is reached.

Conductivity Meter

Supplied Name: Dionex CDM-II conductivity detector

Supplied Description:

Used to measure dissolved inorganic carbon.

Instrument Type

Generic Name: Conductivity Meter

Generic Description:

Conductivity Meter - An electrical conductivity meter (EC meter) measures the electrical conductivity in a solution. Commonly used in hydroponics, aquaculture and freshwater systems to monitor the amount of nutrients, salts or impurities in the water.

Ion Chromatograph

Supplied Name: Thermo-Fisher Dionex ICS-5000 ion chromatograph

Supplied Description:

Used to measure sulfate.

Instrument Type

Generic Name: Ion Chromatograph

Generic Description:

Ion chromatography is a form of liquid chromatography that measures concentrations of ionic species by separating them based on their interaction with a resin. Ionic species separate differently depending on species type and size. Ion chromatographs are able to measure concentrations of major anions, such as fluoride, chloride, nitrate, nitrite, and sulfate, as well as major cations such as lithium, sodium, ammonium, potassium, calcium, and magnesium in the parts-per-billion (ppb) range. (from http://serc.carleton.edu/microbelife/research_methods/biogeochemical/ic.html)

Total Organic Carbon Analyzer

Supplied Name: Shimadzu TOC-V total carbon analyzer

Supplied Description:

Used to measure dissolved organic carbon.

Instrument Type

Generic Name: Total Organic Carbon Analyzer

Acronym: TOC analyzer

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB04/

Generic Description:

A unit that accurately determines the carbon concentrations of organic compounds typically by detecting and measuring its combustion product (CO2). See description document at: http://bcodata.whoi.edu/LaurentianGreatLakes_Chemistry/bs116.pdf

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
initial_pH	initial pH determined during alkalinity titrations	NBS scale	pH
initial_pH_stdev	initial pH determined during alkalinity titrations	NBS scale	pH
lat	latitude; north is positive	decimal degrees	lat
ISO_DateTime_Local_collected	local date and time collected formatted as YYYY-MM-DDTHH:MM:SS (ISO 8601:2004€ )	unitless	date_local
lon	longitude; east is positive	decimal degrees	lon
num_replicate_bottles	number of replicate bottles collected	bottles	num_reps
Alk	pore water alkalinity	milliMoles	TALK
DIC_stdev	pore water dissolved ammonium	microMoles	DIC
Sulfate_stdev	pore water dissolved inorganic carbon	milliMoles	SO4
DIC	pore water dissolved iron	microMoles	DIC
DOC_stdev	pore water dissolved organic carbon	microMoles	DOC
Alk_stdev	pore water sulfate	milliMoles	TALK
DOC	pore water total dissolved sulfide	microMoles	DOC
sample_id	sample id	unitless	core_id
site	site	unitless	site
Sulfate	standard deviation of sulfate concentration	milliMoles	SO4