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| Dataset Title: | [Sediment iron] - Sediment iron data from sediment cores collected on the R/V Nathaniel B. Palmer cruise NBP1601 to the West Antarctic continental shelf in January of 2016 (Organic Carbon Oxidation and Iron Remobilization by West Antarctic Shelf Sediments) 
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| Institution: | BCO-DMO (Dataset ID: bcodmo_dataset_813152) |
| Information: | Summary
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Attributes {
s {
St_ID {
String bcodmo_name "station";
String description "station ID number";
String long_name "St ID";
String units "unitless";
}
Sa_ID {
String bcodmo_name "sample";
String description "sample ID (stat ID #-core ID #- sample number)";
String long_name "Sa ID";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P02/current/ACYC/";
String units "unitless";
}
Core {
String bcodmo_name "sample_type";
String description "core type (M = mega-corer; K = Kasten corer)";
String long_name "Core";
String units "unitless";
}
Depth {
Float32 _FillValue NaN;
Float32 actual_range 0.25, 225.0;
String bcodmo_name "depth_bsf";
Float64 colorBarMaximum 8000.0;
Float64 colorBarMinimum -8000.0;
String colorBarPalette "TopographyDepth";
String description "sediment depth (relative to the sediment-water interface)";
String long_name "Depth";
String standard_name "depth";
String units "centimeters (cm)";
}
error {
Float32 _FillValue NaN;
Float32 actual_range 0.25, 5.0;
String bcodmo_name "sample_descrip";
Float64 colorBarMaximum 50.0;
Float64 colorBarMinimum 0.0;
String description "Half of the thickness of the sediment sample";
String long_name "Error";
String units "centimeters (cm)";
}
Fe_II_HCl {
Float32 _FillValue NaN;
Float32 actual_range 0.0, 0.2;
String bcodmo_name "Fe";
String description "concentration of iron in the Fe(II) HCl extract. See methodology for more details.";
String long_name "Fe II HCl";
String units "grams of iron per 100 grams dried sediment (wt% Fe)";
}
Fe_ox1 {
Float32 _FillValue NaN;
Float32 actual_range 0.0, 0.73;
String bcodmo_name "Fe";
String description "concentration of iron in the Fe ox1 extract. See methodology for more details.";
String long_name "Fe Ox1";
String units "grams of iron per 100 grams dried sediment (wt% Fe)";
}
Fe_ox2 {
Float32 _FillValue NaN;
Float32 actual_range 0.07, 0.66;
String bcodmo_name "Fe";
String description "concentration of iron in the Fe ox2 extract. See methodology for more details.";
String long_name "Fe Ox2";
String units "grams of iron per 100 grams dried sediment (wt% Fe)";
}
Fe_mag {
Float32 _FillValue NaN;
Float32 actual_range 0.14, 0.69;
String bcodmo_name "Fe";
String description "concentration of iron in the Fe(mag) extract. See methodology for more details.";
String long_name "Fe Mag";
String units "grams of iron per 100 grams dried sediment (wt% Fe)";
}
Fe_prs {
Float32 _FillValue NaN;
Float32 actual_range 0.25, 3.77;
String bcodmo_name "Fe";
String description "concentration of iron in the Fe(prs) extract. See methodology for more details.";
String long_name "Fe Prs";
String units "grams of iron per 100 grams dried sediment (wt% Fe)";
}
Fe_AVS {
Float32 _FillValue NaN;
Float32 actual_range 2.74e-5, 0.00115;
String bcodmo_name "Fe";
String description "concentration of iron in the acid volatile sulfide (AVS) extract. See methodology for more details.";
String long_name "Fe AVS";
String units "grams of iron per 100 grams dried sediment (wt% Fe)";
}
Fe_pyr {
Float32 _FillValue NaN;
Float32 actual_range 3.15e-5, 0.207;
String bcodmo_name "Fe";
String description "concentration of iron in the AVS + pyrite extract. See methodology for more details.";
String long_name "Fe Pyr";
String units "grams of iron per 100 grams dried sediment (wt% Fe)";
}
Fe_U {
Float32 _FillValue NaN;
Float32 actual_range 0.51, 7.68;
String bcodmo_name "Fe";
String description "concentration of “unreactive” iron. See methodology for more details.";
String long_name "Fe U";
String units "grams of iron per 100 grams dried sediment (wt% Fe)";
}
Fe_T {
Float32 _FillValue NaN;
Float32 actual_range 2.77, 9.66;
String bcodmo_name "Fe";
String description "concentration of total sediment iron. See methodology for more details.";
String long_name "Fe T";
String units "grams of iron per 100 grams dried sediment (wt% Fe)";
}
time {
String _CoordinateAxisType "Time";
Float64 actual_range 1.45279284e+9, 1.54866816e+9;
String axis "T";
String bcodmo_name "ISO_DateTime_UTC";
String description "station timestamp (UTC) in ISO 8601 format yyyy-mm-ddTHH:MMZ";
String ioos_category "Time";
String long_name "ISO Date Time UTC";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P01/current/DTUT8601/";
String source_name "ISO_DateTime_UTC";
String standard_name "time";
String time_origin "01-JAN-1970 00:00:00";
String time_precision "1970-01-01T00:00Z";
String units "seconds since 1970-01-01T00:00:00Z";
}
latitude {
String _CoordinateAxisType "Lat";
Float64 _FillValue NaN;
Float64 actual_range -67.7717, -64.1583;
String axis "Y";
String bcodmo_name "latitude";
Float64 colorBarMaximum 90.0;
Float64 colorBarMinimum -90.0;
String description "station latitude, south is negative";
String ioos_category "Location";
String long_name "Latitude";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P09/current/LATX/";
String standard_name "latitude";
String units "degrees_north";
}
longitude {
String _CoordinateAxisType "Lon";
Float64 _FillValue NaN;
Float64 actual_range -71.2217, -62.7317;
String axis "X";
String bcodmo_name "longitude";
Float64 colorBarMaximum 180.0;
Float64 colorBarMinimum -180.0;
String description "station longitude, west is negative";
String ioos_category "Location";
String long_name "Longitude";
String nerc_identifier "https://vocab.nerc.ac.uk/collection/P09/current/LONX/";
String standard_name "longitude";
String units "degrees_east";
}
}
NC_GLOBAL {
String access_formats ".htmlTable,.csv,.json,.mat,.nc,.tsv,.esriCsv,.geoJson,.odvTxt";
String acquisition_description
"Sediment and pore water collection:
Short sediment cores were collected using a Bowers & Connelly megacorer, a
multiple coring device that can collect ~20-40 cm long sediment cores with
undisturbed sediment surfaces. At two sites (stations 41 and 64) longer cores
(up to ~2 m) were also collected with a Kasten corer.
Megacorer cores were either sectioned for solid phase analysis, profiled with
polarographic micro-electrodes to determine dissolved O2 concentrations, or
sectioned in a cold van under N2 for pore water sample extraction (for details
see, Komada et al., 2016). Samples for solid phase analyses were placed in
Whirl-Pak plastic bags and frozen for solid phase Fe speciation analyses at
ODU.
Kasten cores were brought into a large cold room on-board ship, laid on their
side and one side of the core box removed to expose the sediment in the core.
A plastic block was placed against the top of the core to prevent slumping of
the sediment during processing, and pore waters were collected from these
cores using Rhizon samplers (Seeberg-Elverfeldt et al., 2005) inserted
directly into the cores at measured intervals. After pore water sampling was
complete, samples for solid phase analyses were removed from the cores with
plastic spoons and again placed in Whirl-Pak plastic bags (Fe speciation
analyses) and immediately frozen.
While it is possible to recover cores with intact sediment-water interfaces
using a megacorer, loss of surface sediments is typical during Kasten coring,
making it not possible to directly determine absolute depths below the
sediment-water interface in a Kasten core. We therefore determined the
absolute depths of pore water and solid phase sample intervals from Kasten
cores by aligning Kasten core profiles of pore water alkalinity to megacore
alkalinity profiles from the same site (Berelson et al., 2005; Komada et al.,
2016).
Sediment iron speciation:
This was determined using sequential extraction techniques (Goldberg et al.,
2012; Poulton and Canfield, 2005). Sediments were freeze-dried and homogenized
before use, and in each step a 10 ml extraction volume was used (except where
noted) starting with 200-300 mg of sediment. Samples were shaken during all
extractions, except when heated during extractions. At the end of each
extraction step, the samples were centrifuged, the extract solution was
removed, and the sediments were then rinsed twice with distilled, deionized
water before moving on to the next extraction. Except where noted all extracts
were analyzed for iron by flame AAS (Atomic Absorption Spectrometry).
Sediments were initially treated with 0.5 M HCl for 1 h to remove highly
reactive, poorly crystalline iron oxides such as ferrihydrite and
lepidochrocite, as well as any unsulfidized Fe(II) produced during early
diagenesis. Fe(II) released by the 0.5 M HCl extraction (termed Fe_II_HCl) was
determined immediately by the ferrozine method (Viollier et al., 2000) without
the addition of hydrolyamine HCl using an aliquot of the extract solution.
Subtraction of the Fe concentration determined by the Fe_II_HCl measurement
from the total Fe present in the 0.5 M HCl extract (Fe_HCl) yields the
concentration of highly reactive, poorly crystalline Fe oxides (Fe_ox1),
Fe_ox1 = Fe_HCl \\u2013 Fe_II_HCl\\t\\t(1)
Next, the sediment was extracted for 6 hr with a citrate-dithionite solution
(50 g /l sodium dithionite buffered to pH 4.8 with 0.35 M acetic acid/0.2 M
sodium citrate) to extract less reactive crystalline iron oxides such as
goethite and hematite (Fe_ox2). After this, the sediment was extracted with
ammonium oxalate (0.2 M ammonium oxalate/0.17 M oxalic acid) at pH 3.2 for 6
hr to dissolve iron in the mineral phase magnetite (Fe_mag). Finally, the
remaining sediment was placed in boiling 12N HCl (5 ml) for 1 min to extract
Fe found in poorly reactive sheet silicates (Fe_prs; i.e.,
\\u201cstructural\\u201d Fe(III) in clays).
Total sediment iron (Fe_T) was determined in a separate sediment aliquot by
ashing the sediment at 450\\u00b0C for 8 h followed by extraction for 24 h in
near boiling 6 N HCl. Finally, iron in the sulfide-containing phases AVS and
pyrite (termed Fe_pyr) was determined in a separate sediment aliquot by acidic
chromium reduction/distillation and colorimetric analysis of the sulfide
liberated by the process. This procedure was based on that described in
Canfield et al. (1986) with the exception that we used 150-200 mg sediment
samples, and collected the sulfide produced by the distillation process in
three sequential traps (trap volumes of 30, 30 and 20 ml) containing 5 mM each
ZnCl2 and NaOH (final concentrations; Ingvorsen and J\\u00f8rgensen, 1979). The
distillation was done using a sparging rate of 250 ml N2/min for 45 \\u2013 60
min. Sulfide in the traps was determined colorimetrically (Cline, 1969), and
the concentration of iron in this pool was calculated by assuming that all of
the sulfide liberated by this procedure is pyrite-S (i.e., that there is no
AVS in these sediments) with a 1:2 Fe:S molar ratio in the pyrite.
Finally, we also defined a pool of unreactive iron (Fe_U) whose concentration
is given by\\t
\\tFe_U = Fe_T \\u2013 (Fe_ox1 + Fe_ox2 + Fe_II_HCl + Fe_mag + Fe_prs + Fe_pyr
)\\t (2)
This iron is presumably found in mineral phases that are even less reactive
towards reductive dissolution than iron in any of these other extracts.";
String awards_0_award_nid "806863";
String awards_0_award_number "OPP-1551195";
String awards_0_data_url "http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=1551195";
String awards_0_funder_name "NSF Division of Ocean Sciences";
String awards_0_funding_acronym "NSF OCE";
String awards_0_funding_source_nid "355";
String awards_0_program_manager "Michael E. Jackson";
String awards_0_program_manager_nid "806862";
String cdm_data_type "Other";
String comment
"Sediment iron
PI: David J Burdige
Data Version 1: 2020-06-08";
String Conventions "COARDS, CF-1.6, ACDD-1.3";
String creator_email "info@bco-dmo.org";
String creator_name "BCO-DMO";
String creator_type "institution";
String creator_url "https://www.bco-dmo.org/";
String data_source "extract_data_as_tsv version 2.3 19 Dec 2019";
String dataset_current_state "Final and no updates";
String date_created "2020-05-27T22:57:12Z";
String date_modified "2020-06-17T15:10:09Z";
String defaultDataQuery "&time<now";
String doi "10.26008/1912/bco-dmo.813152.1";
Float64 Easternmost_Easting -62.7317;
Float64 geospatial_lat_max -64.1583;
Float64 geospatial_lat_min -67.7717;
String geospatial_lat_units "degrees_north";
Float64 geospatial_lon_max -62.7317;
Float64 geospatial_lon_min -71.2217;
String geospatial_lon_units "degrees_east";
String history
"2024-12-27T01:30:23Z (local files)
2024-12-27T01:30:23Z https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_813152.html";
String infoUrl "https://www.bco-dmo.org/dataset/813152";
String institution "BCO-DMO";
String instruments_0_acronym "Gravity Corer";
String instruments_0_dataset_instrument_nid "814585";
String instruments_0_description "The gravity corer allows researchers to sample sediment layers at the bottom of lakes or oceans. The coring device is deployed from the ship and gravity carries it to the seafloor. (https://www.whoi.edu/instruments/viewInstrument.do?id=1079).";
String instruments_0_instrument_external_identifier "https://vocab.nerc.ac.uk/collection/L05/current/51/";
String instruments_0_instrument_name "Gravity Corer";
String instruments_0_instrument_nid "531";
String instruments_0_supplied_name "Kasten corer";
String instruments_1_acronym "Multi Corer";
String instruments_1_dataset_instrument_nid "814584";
String instruments_1_description "The Multi Corer is a benthic coring device used to collect multiple, simultaneous, undisturbed sediment/water samples from the seafloor. Multiple coring tubes with varying sampling capacity depending on tube dimensions are mounted in a frame designed to sample the deep ocean seafloor. For more information, see Barnett et al. (1984) in Oceanologica Acta, 7, pp. 399-408.";
String instruments_1_instrument_external_identifier "https://vocab.nerc.ac.uk/collection/L05/current/51/";
String instruments_1_instrument_name "Multi Corer";
String instruments_1_instrument_nid "532";
String instruments_1_supplied_name "Bowers & Connelly megacorer";
String keywords "avs, bco, bco-dmo, biological, chemical, core, data, dataset, date, depth, dmo, erddap, error, Fe_AVS, Fe_II_HCl, Fe_mag, Fe_ox1, Fe_ox2, Fe_prs, Fe_pyr, Fe_T, Fe_U, hcl, iso, latitude, longitude, mag, management, oceanography, office, ox1, ox2, preliminary, prs, pyr, Sa_ID, St_ID, time, u";
String license "https://www.bco-dmo.org/dataset/813152/license";
String metadata_source "https://www.bco-dmo.org/api/dataset/813152";
Float64 Northernmost_Northing -64.1583;
String param_mapping "{'813152': {'Lat': 'master - latitude', 'Lon': 'master - longitude', 'ISO_DateTime_UTC': 'master - time'}}";
String parameter_source "https://www.bco-dmo.org/mapserver/dataset/813152/parameters";
String people_0_affiliation "Old Dominion University";
String people_0_affiliation_acronym "ODU";
String people_0_person_name "David J Burdige";
String people_0_person_nid "648653";
String people_0_role "Principal Investigator";
String people_0_role_type "originator";
String people_1_affiliation "New England Oceanographic Laboratory";
String people_1_affiliation_acronym "NEOL";
String people_1_person_name "John P Christensen";
String people_1_person_nid "51603";
String people_1_role "Co-Principal Investigator";
String people_1_role_type "originator";
String people_2_affiliation "Woods Hole Oceanographic Institution";
String people_2_affiliation_acronym "WHOI BCO-DMO";
String people_2_person_name "Amber D. York";
String people_2_person_nid "643627";
String people_2_role "BCO-DMO Data Manager";
String people_2_role_type "related";
String project "Antarctic Shelf Sediments";
String projects_0_acronym "Antarctic Shelf Sediments";
String projects_0_description
"NSF Award Abstract:
General Statement:
The continental shelf region west of the Antarctic Peninsula has recently undergone dramatic changes and ecosystem shifts, and the community of organisms that live in, or feed off, the sea floor sediments is being impacted by species invasions from the north. Previous studies of these sediments indicate that this community may consume much more of the regional productivity than previously estimated, suggesting that sediments are a rich and important component of this ecosystem and one that may be ripe for dramatic change. Furthermore, under richer sediment conditions, iron is mobilized and released back to the water column. Since productivity in this ecosystem is thought to be limited by the availability of iron, increased rates of iron release from these sediments could stimulate productivity and promote greater overall ecosystem change. In this research, a variety of sites across the shelf region will be sampled to accurately evaluate the role of sediments in consuming ecosystem productivity and to estimate the current level of iron release from the sediments. This project will provide a baseline set of sediment results that will present a more complete picture of the west Antarctic shelf ecosystem, will allow for comparison with water column measurements and for evaluation of the fundamental workings of this important ecosystem. This is particularly important since high latitude systems may be vulnerable to the effects of climate fluctuations. Both graduate and undergraduate students will be trained. Presentations will be made at scientific meetings, at other universities, and at outreach events. A project web site will present key results to the public and explain how this new information improves understanding of Antarctic ecosystems.
Technical Description of Project:
In order to determine the role of sediments within the west Antarctic shelf ecosystem, this project will determine the rates of sediment organic matter oxidation at a variety of sites across the Palmer Long Term Ecosystem Research (LTER) study region. To estimate the rates of release of iron and manganese from the sediments, these same sites will be sampled for detailed vertical distributions of the concentrations of these metals both in the porewaters and in important mineral phases. Since sediment sampling will be done at LTER sites, the sediment data can be correlated with the rich productivity data set from the LTER. In detail, the project: a) will determine the rates of oxygen consumption, organic carbon oxidation, nutrient release, and iron mobilization by shelf sediments west of the Antarctic Peninsula; b) will investigate the vertical distribution of diagenetic reactions within the sediments; and c) will assess the regional importance of these sediment rates. Sediment cores will be used to determine sediment-water fluxes of dissolved oxygen, total carbon dioxide, nutrients, and the vertical distributions of these dissolved compounds, as well as iron and manganese in the pore waters. Bulk sediment properties of porosity, organic carbon and nitrogen content, carbonate content, biogenic silica content, and multiple species of solid-phase iron, manganese, and sulfur species will also be determined. These measurements will allow determination of total organic carbon oxidation and denitrification rates, and the proportion of aerobic versus anaerobic respiration at each site. Sediment diagenetic modeling will link the processes of organic matter oxidation to metal mobilization. Pore water and solid phase iron and manganese distributions will be used to model iron diagenesis in these sediments and to estimate the iron flux from the sediments to the overlying waters. Finally, the overall regional average and distribution of the sediment processes will be compared with the distributions of seasonally averaged chlorophyll biomass and productivity.";
String projects_0_end_date "2020-02";
String projects_0_geolocation "West Antarctic Continental Shelf";
String projects_0_name "Organic Carbon Oxidation and Iron Remobilization by West Antarctic Shelf Sediments";
String projects_0_project_nid "806864";
String projects_0_start_date "2015-09";
String publisher_name "Biological and Chemical Oceanographic Data Management Office (BCO-DMO)";
String publisher_type "institution";
String sourceUrl "(local files)";
Float64 Southernmost_Northing -67.7717;
String standard_name_vocabulary "CF Standard Name Table v55";
String summary "Sediment iron data from sediment cores collected on the R/V Nathaniel B. Palmer cruise NBP1601 to the West Antarctic continental shelf in January of 2016.";
String time_coverage_end "2019-01-28T09:36Z";
String time_coverage_start "2016-01-14T17:34Z";
String title "[Sediment iron] - Sediment iron data from sediment cores collected on the R/V Nathaniel B. Palmer cruise NBP1601 to the West Antarctic continental shelf in January of 2016 (Organic Carbon Oxidation and Iron Remobilization by West Antarctic Shelf Sediments)";
String version "1";
Float64 Westernmost_Easting -71.2217;
String xml_source "osprey2erddap.update_xml() v1.5";
}
}
Data Access Protocol (DAP) and its
selection constraints.
The URL specifies what you want: the dataset, a description of the graph or the subset of the data, and the file type for the response.
Tabledap request URLs must be in the form
https://coastwatch.pfeg.noaa.gov/erddap/tabledap/datasetID.fileType{?query}
For example,
https://coastwatch.pfeg.noaa.gov/erddap/tabledap/pmelTaoDySst.htmlTable?longitude,latitude,time,station,wmo_platform_code,T_25&time>=2015-05-23T12:00:00Z&time<=2015-05-31T12:00:00Z
Thus, the query is often a comma-separated list of desired variable names,
followed by a collection of
constraints (e.g., variable<value),
each preceded by '&' (which is interpreted as "AND").
For details, see the tabledap Documentation.