ERDDAP > info > bcodmo_dataset_786508

Grid DAP Data	Sub- set	Table DAP Data	Make A Graph	W M S	Source Data Files	Acces- sible	Title	Sum- mary	FGDC, ISO, Metadata	Back- ground Info	RSS	E mail	Institution	Dataset ID
	set	data	graph		files	public	[Stable Isotopes in Reactive Si Pools] - Stable isotopes in reactive silica pools of Mississippi River plume sediments collected aboard the R/V Pelican in May 2017 (The biotic and abiotic controls on the Silicon cycle in the northern Gulf of Mexico)		F   I   M	background			BCO-DMO	bcodmo_dataset_786508

The Dataset's Variables and Attributes

Row Type	Variable Name	Attribute Name	Data Type	Value
attribute	NC_GLOBAL	access_formats	String	.htmlTable,.csv,.json,.mat,.nc,.tsv,.esriCsv,.geoJson,.odvTxt
attribute	NC_GLOBAL	acquisition_description	String	Stable silicon isotopes (e.g. \u03b430Si) in sediment biogenic silica (bSi) are widely used as a paleoproxy for marine silicic acid usage by pelagic diatoms. Despite the growing body of work that uses bSi \u03b430Si signals, there are a lack of \u03b430Si data on other reactive pools of Si in sediments. This oversight misses valuable information on early diagenetic products and potentially biases existing sedimentary bSi \u03b430Si, which only quantified bSi fractions not altered by diagenesis. For the first time, we quantified \u03b430Si among operationally defined reactive Si pools (using a pre-leach of mild acid prior to alkaline digestion) in Mississippi River plume sediments. We compared the \u03b430Si signal within these reactive Si pools to a traditional alkaline-only digestion of sedimentary bSi. These data offer proof of concept that \u03b430Si is a higher throughput approach for quantifying isotopic properties among reactive Si pools marine sediments vs. the more laborious (albeit powerful) examination of natural silicon radioisotopes in these chemical leaches. Core Sampling Briefly, samples were acquired from the study area using an Ocean Instruments MC-900 Multi-corer, which preserved the sediment-water interface during recovery. Overlying bottom water was removed, cores were sectioned into 1cm slices, homogenized, packed under N2 gas and frozen at -20o C for further analysis. Operational Definitions Operational reactive Si pools have previously been defined by Rahman et al. (2016) but for consistency and clarity with previous literature (DeMaster, 1981; Michalopoulos and Aller, 2004; Qin et al., 2012; Wang et al., 2015; Rahman et al., 2016; Krause et al., 2017) it has been restated here. Therefore we use the following nomenclature; 1\. Si-HCl: Mild acid-leachable pre-treatment; Highly reactive silica associated with authigenic clays and metal oxide coatings (Michalopoulos and Aller, 2004). 2. Si-Alk: Mild alkaline-leachable digestion completed after acid pretreatment; Frees reactive silica associated with the biogenic silica pool (Michalopoulos and Aller, 2004). 3. Si-NaOH: Harsh NaOH digestion done after Si-HCl and Si-Alk (Rahman et al., 2016; Rahman et al., 2017); Associated with the reactive lithogenic Si (LSi) pool and the comparatively refractory \u201cdark bSiO2\u201d (e.g. sponge spicules and Rhizaria, Maldonado et al., 2019). 4. T-bSi: Following the traditional definition of biogenic silica (DeMaster, 1981), with no acid pre-treatment. Reactive Silica Pools Frozen sediment samples were thawed to room temperature (22o C) and triplicate ~50-100 mg subsamples were immediately weighed into 50 mL polyethylene centrifuge tubes. Samples were never dried or ground before/during extractions. Procedural blanks were also prepared in triplicate. Additional subsamples of sediment were dried at 60o C to obtain correction for water content. Sequential Extractions The sequential extraction methodology separates silica into operationally defined pools based on kinetics, reaction conditions and reaction sequence (DeMaster, 1981; Michalopoulos and Aller, 2004; Rahman et al., 2016). Acid Leachable Silica (Si-HCl) Sediment extractions occurred at room temperature (22o C) using Honeywell Fluka Trace SELECT 0.1 N HCl for 12 hrs, while keeping particles suspended via constant motion. Following centrifugation, the Si-HCl leachate was removed and neutralized. Remaining sediment was rinsed in triplicate with Milli-Q water to remove any residual acid (Michalopoulos and Aller, 2004). As it had previously been demonstrated by Rahman et al. (2016) that the rinses contained minor amounts of Si these rinses were discarded. A weak HCl molarity was purposely chosen to remove metal coatings, authigenic phases, and activate bSi surfaces while not affecting the sequential Si-Alk digestion (Michalopoulos and Aller, 2004). Mild Alkaline Leachable Si (Si-Alk) The remaining sediment from the acid pre-treatment was subsequently digested with 0.1 M Na2CO3 (Fisher Scientific Certified ACS) for 20 mins in a 85o C water bath. Following the 20 min timepoint, samples were placed on ice and neutralized to stop the digestion. Following centrifugation, the Si-Alk leachate was removed and stored for further use. The process was stopped after 20 mins to ensure the absence of lithogenic material (DeMaster, 1981; Michalopoulos and Aller, 2004) and certify that the clear majority of solubilized silica present is biogenic. Fresh 0.1 M Na2CO3 was added to the samples and the digestions were continued for a total of 5 hrs (DeMaster, 1981) to completely remove the bSi phase. Concluding after 5 hrs, samples were placed on ice and neutralized to stop the digestion. Following centrifugation, the leachate was removed and discarded. Remaining sediment was rinsed in triplicate with Milli-Q water to remove any residual Na2CO3 and again the rinses were discarded. Harsh NaOH Digestion (Si-NaOH) The remaining sediment from the Si-Alk treatment was subsequently digested with Honeywell Fluka 4 M NaOH for 2 hrs in a 85o C water bath. After 2 hrs, samples were placed on ice and neutralized to stop the digestion. Following centrifugation, the Si- NaOH leachate was removed, the remaining sediment was rinsed with Milli-Q water to remove any residual leachate and this rinse was added to the Si-NaOH leachate and stored for further analysis (Rahman et al., 2016). Traditional bSi Digestion (T-bSi) Additionally, a second treatment following the traditional definition of biogenic silica (DeMaster, 1981), with no acid pre-treatment was used to derive \u03b430Si from traditional bSi measurements. New subsamples of sediment were weighed out. 0.1 M Na2CO3 was added to samples and heated in a 85o C water bath for 20 mins to remove the bSi phase. Following the 20 min timepoint, samples were placed on ice and neutralized to stop the digestion. Following centrifugation, leachate was removed and stored for further use. Similar to the Si-Alk digestions, the process was stopped after 20 mins to ensure the absence of lithogenic material. A 1 ml aliquot of each resulting liquid (Si-HCl, Si-Alk, Si-NaOH and T-bSi) was analyzed for dissolved SiOH4 concentration (dSi) as described by Brzezinski and Nelson (Brzezinski and Nelson, 1986) using the molybdate-blue method on a Genesys 10S UV-Vis Spectrophotometer. The remaining supernatants were concentrated via evaporation at 100o C and stored following DeMaster (1980) in preparation for stable isotope analysis. Stable Isotope Analysis Sample purification and isotope analysis were carried out at the University of Bristol Isotope Group laboratories. Concentrated sample fluids were purified via cation ion exchange chromatography (Bio-Rad AG50W-X12, 200-400 mesh cation exchange resin in H+ form). Purified solutions were analyzed in duplicate for Si isotopes (28Si, 29Si, 30Si) using a multi collector-inductively coupled plasma-mass spectrometer (MC-ICP-MS, Finnigan Neptune s/n 1002), equipped with CETAC PFA spray chamber and PFA nebulizer (100ul/min). A standard-sample- standard bracketing procedure with Mg doping following Cardinal et al., (2003) was used to correct for both instrumental mass bias and matrix effects. Additionally, sample and standard solutions were both doped with 0.1 M H2SO4 (ROMIL UpA) and 1 M HCl (in-house distilled) to reduce any matrix effects from anion loading and guarantee matrix matching between sample and standard (Hughes et al., 2011). All isotopic composition results are expressed as \u03b430Si, corresponding to the silicon isotopic abundances in samples relative to the international reference standard NBS-28 (NIST RM8546, purified quartz sand). Reference standards Diatomite (Reynolds et al., 2007) and LMG08 (sponge) (Hendry et al., 2011) were run in tandem with samples to assess long- term reproducibility. Average measured values are reported as +1.27 \u00b1 0.09\u2030 (n=75) and -3.47 \u00b1 0.16\u2030 (n=27) (\u00b1SD) respectively, which are well within agreement with published values (Reynolds et al., 2007; Hendry et al., 2011). All samples and standards are consistent with the kinetic mass fractionation law (Reynolds et al., 2007) with the \u03b429Si = 0.518x\u03b430Si. Procedural blanks were lower than the detection limit and thus considered negligible on \u03b430Si of the samples. Major Metal Compositions and Corrections Additional thawed/wet sediment subsamples were used for duplicate sequential extractions and digestions (Si-HCl, Si-Alk, Si-NaOH and T-bSi) run as previously described. Supernatants were concentrated via evaporation at 100o C and fluids were reconstituted in 2% HNO3 (in-house distilled) to determine major ion concentrations on an Agilent 7700 Series ICP-MS. The instrument was calibrated using a blank and seven matrix-matched, mixed standards. Internal standardization during analysis was monitored via the addition of (50 \u03bcl, 10,000 ppb) 115In and 4Be to all standards and samples. Using Aluminum (Al):Si corrections (Kamatani and Oku, 2000; Ragueneau et al., 2005), both Si-Alk and T-bSi \u03b430Si signals (\u2030) and mass of Si released (\u03bcmol/g) were adjusted for bias from lithogenic material (however, this was more important for the mass of Si, as isotopic content was derived from 30-minute digestions, opposed to 5 hour digestions for the former). Organic Matter Sediment total organic carbon (TOC) and total organic nitrogen (TON) content were analyzed at the Dauphin Island Sea Lab using a Costech elemental combustion system (4010 ECS) following vapor phase acidification to remove carbonates. Briefly, dried sediment samples were placed in a glass desiccator and reacted with reagent-grade 12N HCl vapor for 24 hrs at room temperature. Samples were then dried at 60o C overnight to remove remaining HCl and water content before TOC/TON analyses (Yamamuro and Kayanne, 1995).
attribute	NC_GLOBAL	awards_0_award_nid	String	712666
attribute	NC_GLOBAL	awards_0_award_number	String	OCE-1558957
attribute	NC_GLOBAL	awards_0_data_url	String	http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=1558957
attribute	NC_GLOBAL	awards_0_funder_name	String	NSF Division of Ocean Sciences
attribute	NC_GLOBAL	awards_0_funding_acronym	String	NSF OCE
attribute	NC_GLOBAL	awards_0_funding_source_nid	String	355
attribute	NC_GLOBAL	awards_0_program_manager	String	Dr Simone Metz
attribute	NC_GLOBAL	awards_0_program_manager_nid	String	51479
attribute	NC_GLOBAL	cdm_data_type	String	Other
attribute	NC_GLOBAL	comment	String	Isotope Jeffery W. Krause Data Version 1: 2020-02-04
attribute	NC_GLOBAL	Conventions	String	COARDS, CF-1.6, ACDD-1.3
attribute	NC_GLOBAL	creator_email	String	info at bco-dmo.org
attribute	NC_GLOBAL	creator_name	String	BCO-DMO
attribute	NC_GLOBAL	creator_type	String	institution
attribute	NC_GLOBAL	creator_url	String	https://www.bco-dmo.org/
attribute	NC_GLOBAL	data_source	String	extract_data_as_tsv version 2.3 19 Dec 2019
attribute	NC_GLOBAL	date_created	String	2020-01-08T17:06:48Z
attribute	NC_GLOBAL	date_modified	String	2020-03-02T20:28:24Z
attribute	NC_GLOBAL	defaultDataQuery	String	&time<now
attribute	NC_GLOBAL	doi	String	10.1575/1912/bco-dmo.786508.1
attribute	NC_GLOBAL	Easternmost_Easting	double	-89.75004
attribute	NC_GLOBAL	geospatial_lat_max	double	28.94688
attribute	NC_GLOBAL	geospatial_lat_min	double	28.49884
attribute	NC_GLOBAL	geospatial_lat_units	String	degrees_north
attribute	NC_GLOBAL	geospatial_lon_max	double	-89.75004
attribute	NC_GLOBAL	geospatial_lon_min	double	-90.83464
attribute	NC_GLOBAL	geospatial_lon_units	String	degrees_east
attribute	NC_GLOBAL	infoUrl	String	https://www.bco-dmo.org/dataset/786508
attribute	NC_GLOBAL	institution	String	BCO-DMO
attribute	NC_GLOBAL	instruments_0_acronym	String	ICP Mass Spec
attribute	NC_GLOBAL	instruments_0_dataset_instrument_nid	String	786513
attribute	NC_GLOBAL	instruments_0_description	String	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.
attribute	NC_GLOBAL	instruments_0_instrument_external_identifier	String	https://vocab.nerc.ac.uk/collection/L05/current/LAB15/
attribute	NC_GLOBAL	instruments_0_instrument_name	String	Inductively Coupled Plasma Mass Spectrometer
attribute	NC_GLOBAL	instruments_0_instrument_nid	String	530
attribute	NC_GLOBAL	instruments_0_supplied_name	String	Finnigan Neptune s/n 1002 multi collector-inductively coupled plasma-mass spectrometer
attribute	NC_GLOBAL	instruments_1_acronym	String	Spectrophotometer
attribute	NC_GLOBAL	instruments_1_dataset_instrument_nid	String	786512
attribute	NC_GLOBAL	instruments_1_description	String	An instrument used to measure the relative absorption of electromagnetic radiation of different wavelengths in the near infra-red, visible and ultraviolet wavebands by samples.
attribute	NC_GLOBAL	instruments_1_instrument_external_identifier	String	https://vocab.nerc.ac.uk/collection/L05/current/LAB20/
attribute	NC_GLOBAL	instruments_1_instrument_name	String	Spectrophotometer
attribute	NC_GLOBAL	instruments_1_instrument_nid	String	707
attribute	NC_GLOBAL	instruments_1_supplied_name	String	Genesys 10S UV-Vis Spectrophotometer
attribute	NC_GLOBAL	instruments_2_acronym	String	Costech ECS 4010
attribute	NC_GLOBAL	instruments_2_dataset_instrument_nid	String	793025
attribute	NC_GLOBAL	instruments_2_description	String	The ECS 4010 Nitrogen / Protein Analyzer is an elemental combustion analyser for CHNSO elemental analysis and Nitrogen / Protein determination. The GC oven and separation column have a temperature range of 30-110 degC, with control of +/- 0.1 degC.
attribute	NC_GLOBAL	instruments_2_instrument_name	String	Costech International Elemental Combustion System (ECS) 4010
attribute	NC_GLOBAL	instruments_2_instrument_nid	String	793023
attribute	NC_GLOBAL	keywords	String	average, Avg_d30Si, Avg_d30Si_2_Stdev, Avg_Si_Released, Avg_Si_Released_2_Stdev, bco, bco-dmo, biological, bottom, Bottom_Depth, carbon, carbonate, chemical, chemistry, co3, collected, concentration, core, cruise, Cruise_Collected, d30, data, dataset, date, Date_Collected, depth, deviation, dmo, earth, Earth Science > Oceans > Ocean Chemistry > Silicate, erddap, iso, latitude, longitude, management, mass, mass_concentration_of_silicate_in_sea_water, multi, MultiCore, nominal, Nominal_Depth, number, ocean, oceanography, oceans, office, organic, particulate, phase, poc, POC_2_Stdev, pon, PON_2_Stdev, pool, porewater, preliminary, reactive, Reactive_Pool_Treatment, sample, Sample_Depth, science, sea, seawater, silicate, standard, standard deviation, station, Station_Number, stdev, time, Time_Collected, treatment, v, vapor, Vapor_Phase_Carbonate, water
attribute	NC_GLOBAL	keywords_vocabulary	String	GCMD Science Keywords
attribute	NC_GLOBAL	license	String	https://www.bco-dmo.org/dataset/786508/license
attribute	NC_GLOBAL	metadata_source	String	https://www.bco-dmo.org/api/dataset/786508
attribute	NC_GLOBAL	Northernmost_Northing	double	28.94688
attribute	NC_GLOBAL	param_mapping	String	{'786508': {'Latitude_N': 'master - latitude', 'Longitude_W': 'master - longitude', 'ISO_DateTime_UTC': 'flag - time'}}
attribute	NC_GLOBAL	parameter_source	String	https://www.bco-dmo.org/mapserver/dataset/786508/parameters
attribute	NC_GLOBAL	people_0_affiliation	String	Dauphin Island Sea Lab
attribute	NC_GLOBAL	people_0_affiliation_acronym	String	DISL
attribute	NC_GLOBAL	people_0_person_name	String	Rebecca A. Pickering
attribute	NC_GLOBAL	people_0_person_nid	String	786518
attribute	NC_GLOBAL	people_0_role	String	Principal Investigator
attribute	NC_GLOBAL	people_0_role_type	String	originator
attribute	NC_GLOBAL	people_1_affiliation	String	Dauphin Island Sea Lab
attribute	NC_GLOBAL	people_1_affiliation_acronym	String	DISL
attribute	NC_GLOBAL	people_1_person_name	String	Jeffrey W Krause
attribute	NC_GLOBAL	people_1_person_nid	String	544582
attribute	NC_GLOBAL	people_1_role	String	Co-Principal Investigator
attribute	NC_GLOBAL	people_1_role_type	String	originator
attribute	NC_GLOBAL	people_2_affiliation	String	Louisiana State University
attribute	NC_GLOBAL	people_2_affiliation_acronym	String	LSU-DOCS
attribute	NC_GLOBAL	people_2_person_name	String	Kanchan Maiti
attribute	NC_GLOBAL	people_2_person_nid	String	712671
attribute	NC_GLOBAL	people_2_role	String	Co-Principal Investigator
attribute	NC_GLOBAL	people_2_role_type	String	originator
attribute	NC_GLOBAL	people_3_affiliation	String	Dauphin Island Sea Lab
attribute	NC_GLOBAL	people_3_affiliation_acronym	String	DISL
attribute	NC_GLOBAL	people_3_person_name	String	Rebecca A. Pickering
attribute	NC_GLOBAL	people_3_person_nid	String	786518
attribute	NC_GLOBAL	people_3_role	String	Contact
attribute	NC_GLOBAL	people_3_role_type	String	related
attribute	NC_GLOBAL	people_4_affiliation	String	Woods Hole Oceanographic Institution
attribute	NC_GLOBAL	people_4_affiliation_acronym	String	WHOI BCO-DMO
attribute	NC_GLOBAL	people_4_person_name	String	Christina Haskins
attribute	NC_GLOBAL	people_4_person_nid	String	746212
attribute	NC_GLOBAL	people_4_role	String	BCO-DMO Data Manager
attribute	NC_GLOBAL	people_4_role_type	String	related
attribute	NC_GLOBAL	project	String	CLASiC
attribute	NC_GLOBAL	projects_0_acronym	String	CLASiC
attribute	NC_GLOBAL	projects_0_description	String	NSF Award Abstract: The Louisiana Shelf system in the northern Gulf of Mexico is fed by the Mississippi River and its many tributaries which contribute large quantities of nutrients from agricultural fertilizer to the region. Input of these nutrients, especially nitrogen, has led to eutrophication. Eutrophication is the process wherein a body of water such as the Louisiana Shelf becomes enriched in dissolved nutrients that increase phytoplankton growth which eventually leads to decreased oxygen levels in bottom waters. This has certainly been observed in this area, and diatoms, a phytoplankton which represents the base of the food chain, have shown variable silicon/nitrogen (Si/N) ratios. Because diatoms create their shells from silicon, their growth is controlled not only by nitrogen inputs but the availability of silicon. Lower Si/N ratios are showing that silicon may be playing an increasingly important role in regulating diatom production in the system. For this reason, a scientist from the University of South Alabama will determine the biogeochemical processes controlling changes in Si/N ratios in the Louisiana Shelf system. One graduate student on their way to a doctorate degree and three undergraduate students will be supported and trained as part of this project. Also, four scholarships for low-income, high school students from Title 1 schools will get to participate in a month-long summer Marine Science course at the Dauphin Island Sea Laboratory and be included in the research project. The study has significant societal benefits given this is an area where $2.4 trillion gross domestic product revenue is tied up in coastal resources. Since diatoms are at the base of the food chain that is the biotic control on said coastal resources, the growth of diatoms in response to eutrophication is important to study. Eutrophication of the Mississippi River and its tributaries has the potential to alter the biological landscape of the Louisiana Shelf system in the northern Gulf of Mexico by influencing the Si/N ratios below those that are optimal for diatom growth. A scientist from the University of South Alabama believes the observed changes in the Si/N ratio may indicate silicon now plays an important role in regulating diatom production in the system. As such, understanding the biotic and abiotic processes controlling the silicon cycle is crucial because diatoms dominate at the base of the food chain in this highly productive region. The study will focus on following issues: (1) the importance of recycled silicon sources on diatom production; (2) can heavily-silicified diatoms adapt to changing Si/N ratios more effectively than lightly-silicified diatoms; and (3) the role of reverse weathering in sequestering silicon thereby reducing diffusive pore-water transport. To attain these goals, a new analytical approach, the PDMPO method (compound 2-(4-pyridyl)-5-((4-(2-dimethylaminoethylamino-carbamoyl)methoxy)phenyl)oxazole) that quantitatively measures taxa-specific silica production would be used.
attribute	NC_GLOBAL	projects_0_end_date	String	2019-03
attribute	NC_GLOBAL	projects_0_geolocation	String	Northern Gulf of Mexico, specifically the Louisiana Shelf region dominated by the discharge of the Mississippi River on the western side of the delta
attribute	NC_GLOBAL	projects_0_name	String	The biotic and abiotic controls on the Silicon cycle in the northern Gulf of Mexico
attribute	NC_GLOBAL	projects_0_project_nid	String	712667
attribute	NC_GLOBAL	projects_0_start_date	String	2016-04
attribute	NC_GLOBAL	publisher_name	String	Biological and Chemical Oceanographic Data Management Office (BCO-DMO)
attribute	NC_GLOBAL	publisher_type	String	institution
attribute	NC_GLOBAL	sourceUrl	String	(local files)
attribute	NC_GLOBAL	Southernmost_Northing	double	28.49884
attribute	NC_GLOBAL	standard_name_vocabulary	String	CF Standard Name Table v55
attribute	NC_GLOBAL	subsetVariables	String	Cruise_Collected
attribute	NC_GLOBAL	summary	String	Stable isotopes in reactive silica pools of Mississippi River plume sediments collected aboard the R/V Pelican in May 2017
attribute	NC_GLOBAL	time_coverage_end	String	2017-05-06T20:40Z
attribute	NC_GLOBAL	time_coverage_start	String	2017-05-05T18:40Z
attribute	NC_GLOBAL	title	String	[Stable Isotopes in Reactive Si Pools] - Stable isotopes in reactive silica pools of Mississippi River plume sediments collected aboard the R/V Pelican in May 2017 (The biotic and abiotic controls on the Silicon cycle in the northern Gulf of Mexico)
attribute	NC_GLOBAL	version	String	1
attribute	NC_GLOBAL	Westernmost_Easting	double	-90.83464
attribute	NC_GLOBAL	xml_source	String	osprey2erddap.update_xml() v1.3
variable	Cruise_Collected		String
attribute	Cruise_Collected	bcodmo_name	String	Cruise Name
attribute	Cruise_Collected	description	String	local name chosen by project investigators for a research expedition on a vessel as opposed to the formal/official cruise ID
attribute	Cruise_Collected	long_name	String	Cruise Collected
attribute	Cruise_Collected	units	String	dimensionless
variable	MultiCore		String
attribute	MultiCore	bcodmo_name	String	core_id
attribute	MultiCore	description	String	core number/identification
attribute	MultiCore	long_name	String	Multi Core
attribute	MultiCore	units	String	number/identification
variable	Station_Number		String
attribute	Station_Number	bcodmo_name	String	station
attribute	Station_Number	description	String	station identifier
attribute	Station_Number	long_name	String	Station Number
attribute	Station_Number	units	String	dimensionless
variable	Bottom_Depth		byte
attribute	Bottom_Depth	_FillValue	byte	127
attribute	Bottom_Depth	actual_range	byte	20, 47
attribute	Bottom_Depth	bcodmo_name	String	depth_bottom
attribute	Bottom_Depth	description	String	bottom depth in meters
attribute	Bottom_Depth	long_name	String	Bottom Depth
attribute	Bottom_Depth	units	String	meters
variable	latitude		double
attribute	latitude	_CoordinateAxisType	String	Lat
attribute	latitude	_FillValue	double	NaN
attribute	latitude	actual_range	double	28.49884, 28.94688
attribute	latitude	axis	String	Y
attribute	latitude	bcodmo_name	String	latitude
attribute	latitude	colorBarMaximum	double	90.0
attribute	latitude	colorBarMinimum	double	-90.0
attribute	latitude	description	String	latitude in decimal degrees
attribute	latitude	ioos_category	String	Location
attribute	latitude	long_name	String	Latitude
attribute	latitude	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P09/current/LATX/
attribute	latitude	source_name	String	Latitude_N
attribute	latitude	standard_name	String	latitude
attribute	latitude	units	String	degrees_north
variable	longitude		double
attribute	longitude	_CoordinateAxisType	String	Lon
attribute	longitude	_FillValue	double	NaN
attribute	longitude	actual_range	double	-90.83464, -89.75004
attribute	longitude	axis	String	X
attribute	longitude	bcodmo_name	String	longitude
attribute	longitude	colorBarMaximum	double	180.0
attribute	longitude	colorBarMinimum	double	-180.0
attribute	longitude	description	String	longitude in decimal degrees
attribute	longitude	ioos_category	String	Location
attribute	longitude	long_name	String	Longitude
attribute	longitude	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P09/current/LONX/
attribute	longitude	source_name	String	Longitude_W
attribute	longitude	standard_name	String	longitude
attribute	longitude	units	String	degrees_east
variable	Date_Collected		String
attribute	Date_Collected	bcodmo_name	String	date
attribute	Date_Collected	description	String	date when core was collected in the format mmddyyyy
attribute	Date_Collected	long_name	String	Date Collected
attribute	Date_Collected	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P01/current/ADATAA01/
attribute	Date_Collected	units	String	unitless
variable	Time_Collected		String
attribute	Time_Collected	bcodmo_name	String	time
attribute	Time_Collected	description	String	time GMT when core was collected
attribute	Time_Collected	long_name	String	Time Collected
attribute	Time_Collected	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P01/current/AHMSAA01/
attribute	Time_Collected	units	String	HHMM
variable	Sample_Depth		String
attribute	Sample_Depth	bcodmo_name	String	depth_r
attribute	Sample_Depth	description	String	subsection used for analysis
attribute	Sample_Depth	long_name	String	Sample Depth
attribute	Sample_Depth	units	String	centimeters
variable	Nominal_Depth		float
attribute	Nominal_Depth	_FillValue	float	NaN
attribute	Nominal_Depth	actual_range	float	0.5, 9.5
attribute	Nominal_Depth	bcodmo_name	String	depth_core
attribute	Nominal_Depth	description	String	depth used for data plots
attribute	Nominal_Depth	long_name	String	Nominal Depth
attribute	Nominal_Depth	units	String	centimeters
variable	Porewater		float
attribute	Porewater	_FillValue	float	NaN
attribute	Porewater	actual_range	float	39.76, 274.4
attribute	Porewater	bcodmo_name	String	unknown
attribute	Porewater	description	String	concentration of dissolved silica acid Si(OH)4 in porewater collected
attribute	Porewater	long_name	String	Porewater
attribute	Porewater	units	String	uM
variable	Vapor_Phase_Carbonate		float
attribute	Vapor_Phase_Carbonate	_FillValue	float	NaN
attribute	Vapor_Phase_Carbonate	actual_range	float	0.65, 6.98
attribute	Vapor_Phase_Carbonate	bcodmo_name	String	unknown
attribute	Vapor_Phase_Carbonate	description	String	% of carbonates present in the sediment sample via vapor phase acidification
attribute	Vapor_Phase_Carbonate	long_name	String	Vapor Phase Carbonate
attribute	Vapor_Phase_Carbonate	units	String	%
variable	POC		float
attribute	POC	_FillValue	float	NaN
attribute	POC	actual_range	float	0.77, 1.7
attribute	POC	bcodmo_name	String	POC
attribute	POC	description	String	particular organic carbon
attribute	POC	long_name	String	Particulate Organic Carbon
attribute	POC	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P01/current/CORGCAP1/
attribute	POC	units	String	%
variable	POC_2_Stdev		float
attribute	POC_2_Stdev	_FillValue	float	NaN
attribute	POC_2_Stdev	actual_range	float	0.01, 0.16
attribute	POC_2_Stdev	bcodmo_name	String	standard deviation
attribute	POC_2_Stdev	description	String	2 standard deviations of sample variation
attribute	POC_2_Stdev	long_name	String	POC 2 Stdev
attribute	POC_2_Stdev	units	String	dimensionless
variable	PON		float
attribute	PON	_FillValue	float	NaN
attribute	PON	actual_range	float	0.06, 0.19
attribute	PON	bcodmo_name	String	PON
attribute	PON	description	String	particular organic nitrogen
attribute	PON	long_name	String	PON
attribute	PON	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P01/current/MDMAP013/
attribute	PON	units	String	%
variable	PON_2_Stdev		float
attribute	PON_2_Stdev	_FillValue	float	NaN
attribute	PON_2_Stdev	actual_range	float	0.0, 0.03
attribute	PON_2_Stdev	bcodmo_name	String	standard deviation
attribute	PON_2_Stdev	description	String	2 standard deviations of sample variation
attribute	PON_2_Stdev	long_name	String	PON 2 Stdev
attribute	PON_2_Stdev	units	String	dimensionless
variable	Reactive_Pool_Treatment		String
attribute	Reactive_Pool_Treatment	bcodmo_name	String	treatment
attribute	Reactive_Pool_Treatment	description	String	which reactive pool the following data is for
attribute	Reactive_Pool_Treatment	long_name	String	Reactive Pool Treatment
attribute	Reactive_Pool_Treatment	units	String	unitless
variable	Avg_d30Si		float
attribute	Avg_d30Si	_FillValue	float	NaN
attribute	Avg_d30Si	actual_range	float	-3.32, 2.32
attribute	Avg_d30Si	bcodmo_name	String	mean
attribute	Avg_d30Si	description	String	Average d30Si (n=3) for each corresponding reactive Si Pool (- per mille)
attribute	Avg_d30Si	long_name	String	Avg D30 Si
attribute	Avg_d30Si	units	String	0/00
variable	Avg_d30Si_2_Stdev		float
attribute	Avg_d30Si_2_Stdev	_FillValue	float	NaN
attribute	Avg_d30Si_2_Stdev	actual_range	float	0.0, 0.79
attribute	Avg_d30Si_2_Stdev	bcodmo_name	String	standard deviation
attribute	Avg_d30Si_2_Stdev	description	String	Average d30Si (n=3) for each corresponding reactive Si Pool including 2 standard deviations of sample variation
attribute	Avg_d30Si_2_Stdev	long_name	String	Avg D30 Si 2 Stdev
attribute	Avg_d30Si_2_Stdev	units	String	dimensionless
variable	Avg_Si_Released		float
attribute	Avg_Si_Released	_FillValue	float	NaN
attribute	Avg_Si_Released	actual_range	float	8.0, 1294.3
attribute	Avg_Si_Released	bcodmo_name	String	mean
attribute	Avg_Si_Released	description	String	Average Si released (n=3) for each corresponding reactive Si Pool (- micromoles per gram dry sediment)
attribute	Avg_Si_Released	long_name	String	Mass Concentration Of Silicate In Sea Water
attribute	Avg_Si_Released	units	String	umol/g
variable	Avg_Si_Released_2_Stdev		float
attribute	Avg_Si_Released_2_Stdev	_FillValue	float	NaN
attribute	Avg_Si_Released_2_Stdev	actual_range	float	0.5, 380.9
attribute	Avg_Si_Released_2_Stdev	bcodmo_name	String	standard deviation
attribute	Avg_Si_Released_2_Stdev	description	String	Average Si released (n=3) for each corresponding reactive Si Pool including 2 standard deviations of sample variation
attribute	Avg_Si_Released_2_Stdev	long_name	String	Mass Concentration Of Silicate In Sea Water
attribute	Avg_Si_Released_2_Stdev	units	String	dimensionless
variable	Mg		float
attribute	Mg	_FillValue	float	NaN
attribute	Mg	actual_range	float	0.0, 19791.34
attribute	Mg	bcodmo_name	String	Mg
attribute	Mg	description	String	magnesium concentration for each corresponding reactive Si pool
attribute	Mg	long_name	String	MG
attribute	Mg	units	String	ppm
variable	Al		float
attribute	Al	_FillValue	float	NaN
attribute	Al	actual_range	float	247.93, 62795.01
attribute	Al	bcodmo_name	String	Al
attribute	Al	description	String	aluminum concentration for each corresponding reactive Si pool
attribute	Al	long_name	String	Al
attribute	Al	units	String	ppm
variable	K		float
attribute	K	_FillValue	float	NaN
attribute	K	actual_range	float	0.0, 91645.12
attribute	K	bcodmo_name	String	K
attribute	K	description	String	potassium concentration for each corresponding reactive Si pool
attribute	K	long_name	String	K
attribute	K	units	String	ppm
variable	Ti		float
attribute	Ti	_FillValue	float	NaN
attribute	Ti	actual_range	float	0.0, 971.54
attribute	Ti	bcodmo_name	String	Ti
attribute	Ti	description	String	titanium concentration for each corresponding reactive Si pool
attribute	Ti	long_name	String	Ti
attribute	Ti	units	String	ppm
variable	V		float
attribute	V	_FillValue	float	NaN
attribute	V	actual_range	float	4.46, 142.82
attribute	V	bcodmo_name	String	V
attribute	V	description	String	vanadium concentration for each corresponding reactive Si pool
attribute	V	long_name	String	V
attribute	V	units	String	ppm
variable	Cr		float
attribute	Cr	_FillValue	float	NaN
attribute	Cr	actual_range	float	0.0, 236.79
attribute	Cr	bcodmo_name	String	trace_metal_conc
attribute	Cr	description	String	chromium concentration for each corresponding reactive Si pool
attribute	Cr	long_name	String	CR
attribute	Cr	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P03/current/C035/
attribute	Cr	units	String	ppm
variable	Mn		float
attribute	Mn	_FillValue	float	NaN
attribute	Mn	actual_range	float	0.0, 1899.04
attribute	Mn	bcodmo_name	String	Mn
attribute	Mn	description	String	manganese concentration for each corresponding reactive Si pool
attribute	Mn	long_name	String	MN
attribute	Mn	units	String	ppm
variable	Fe		float
attribute	Fe	_FillValue	float	NaN
attribute	Fe	actual_range	float	135.75, 39444.31
attribute	Fe	bcodmo_name	String	Fe
attribute	Fe	description	String	iron concentration for each corresponding reactive Si pool
attribute	Fe	long_name	String	Fe
attribute	Fe	units	String	ppm
variable	Ni		float
attribute	Ni	_FillValue	float	NaN
attribute	Ni	actual_range	float	0.0, 125.27
attribute	Ni	bcodmo_name	String	trace_metal_conc
attribute	Ni	description	String	nickel concentration for each corresponding reactive Si pool
attribute	Ni	long_name	String	Ni
attribute	Ni	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P03/current/C035/
attribute	Ni	units	String	ppm
variable	Cu		float
attribute	Cu	_FillValue	float	NaN
attribute	Cu	actual_range	float	0.0, 39.61
attribute	Cu	bcodmo_name	String	Cu
attribute	Cu	description	String	copper concentration for each corresponding reactive Si pool
attribute	Cu	long_name	String	Cu
attribute	Cu	units	String	ppm
variable	time		double
attribute	time	_CoordinateAxisType	String	Time
attribute	time	actual_range	double	1.4940096E9, 1.4941032E9
attribute	time	axis	String	T
attribute	time	bcodmo_name	String	ISO_DateTime_UTC
attribute	time	description	String	Date/Time (UTC) ISO formatted
attribute	time	ioos_category	String	Time
attribute	time	long_name	String	ISO Date Time UTC
attribute	time	nerc_identifier	String	https://vocab.nerc.ac.uk/collection/P01/current/DTUT8601/
attribute	time	source_name	String	ISO_DateTime_UTC
attribute	time	standard_name	String	time
attribute	time	time_origin	String	01-JAN-1970 00:00:00
attribute	time	time_precision	String	1970-01-01T00:00Z
attribute	time	units	String	seconds since 1970-01-01T00:00:00Z

The information in the table above is also available in other file formats (.csv, .htmlTable, .itx, .json, .jsonlCSV1, .jsonlCSV, .jsonlKVP, .mat, .nc, .nccsv, .tsv, .xhtml) via a RESTful web service.