<div><p>See Estes el al. (2019) for complete methods. </p>
<p>Sediment slurries were generated by subsampling ~0.1 g of wet sediment from samples stored at 4 °C into a sterile microcentrifuge tube. Then, 0.2–0.5 ml of 0.2 μm filtered 18 MΩ water was added<br />
and the sample shaken. Sediment slurry (1–10 μl) was pipetted onto silicon wafers and air-dried. The beamline was operated with a 500 l mm–1 spherical grating monochromator and entrance and exit slits set to 40 μm, which yielded an absolute energy resolution of less than 0.3 eV. The samples were attached to an aluminium sample stick in a single load and analysed under ultrahigh vacuum conditions (pressure ~10−9 mbar). The measurements were made in the total electron yield (TEY) mode on a spot size of less than 1 mm2 using a grazing incidence angle<br />
of 45°, where previous trials determined that the incidence angle did not yield a<br />
difference in results. The TEY mode was selected instead of fluorescence as we observed dampening of the fluorescence signal, probably due to matrix-induced absorption.</p>
<p>Spectra were collected around the C 1s edge, from 260 to 340 eV, with a dwell time of 0.2 s. To avoid beam damage and variation of the background due to charging, scans were taken at different positions on the sample. The spectra analysed were the average of 2–3 scans taken at different positions on the sample. The dark current was measured prior to the collection of each spectrum and subtracted from the raw data. Spectra were then normalized to no load current measured by a mesh upstream of the chamber with freshly evaporated gold.</p>
<p>Instruments: </p>
<p>Bulk carbon NEXAFS spectroscopy was conducted on beamlines 8-2 and 10-1 at the Stanford Synchrotron Radiation Lightsource.</p>
<p>The absolute energy calibration of the carbon spectra was achieved by shifting the energy such that the first dip in the incoming intensity due to carbon contamination on the beamline optics (carbon dip) occurred at 284.7 eV.</p></div>
<div><p>Carbon near edge X-ray absorption fine structure (NEXAFS) spectra from pelagic sediment from the North Atlantic gyre, South Pacific gyre, and Peru Basin from cruises KN223 (R/V Knorr), KNOX02RR (R/V Roger Revelle), and ODP leg 201 between 2002 and 2014. </p>
<p>These data were published in Estes et al. (2019).</p>
<p>These data are available in two forms (see Data Processing Description section on this page for more information).</p></div>
Carbon NEXAFS bulk data
<div><p>Spectral processing was completed by subtracting a line fit to the pre-edge region (281–283 eV), followed by an area normalization between 282 and 310 eV with the high-energy intensity kept constant (atomic normalization). The entire pre-edge region appeared linear; fitting and background subtraction was conducted over a smaller energy range due to the presence of oxygen harmonic peaks. All the data normalization was conducted in Igor Pro (WaveMetrics).</p>
<p>BCO-DMO Data Manager Processing Notes:<br />
* exported data in xlsx file "Estes_bulkNEXAFSspectra_data.xlsx" to csv file "Estes_bulkNEXAFSspectra_data.csv" which is available to download in the "Data Files" section of this page. The following changes were made after discussion with the original submitter.<br />
* original data had 10 header rows with sample, and cruise information e.g. cruise_id, date, latitude, sample_depth, etc. The data were unpivoted so these values became new columns in the dataset.<br />
* added a conventional header with dataset name, PI name, version date<br />
* modified parameter names to conform with BCO-DMO naming conventions<br />
* blank values in this dataset are displayed as "nd" for "no data." nd is the default missing data identifier in the BCO-DMO system.<br />
* latitude and longitude in degrees decimal minutes converted to decimal degrees then rounded to 5 decimal places.<br />
* date format converted to ISO 8601 format yyyy-mm-dd<br />
* added sample_comment column to capture the difference between the two columns with header information "South Pacific;Knox02-RR;11-Jan-07;9;38° 03.7' S;133° 05.5' W;4924;piston;5.125" in the original file (columns CE and CF in original data).<br />
* data sorted by {location}{expedition}{date}{latitude}{longitude}{water_depth}{core_type}{core_depth}{sample_comment}{eV}<br />
* absorption values rounded to 5 decimal places</p></div>
815380
Carbon NEXAFS bulk data
2020-06-15T17:58:56-04:00
2020-06-15T17:58:56-04:00
2023-09-07T09:43:25-04:00
urn:bcodmo:dataset:815380
Carbon near edge X-ray absorption fine structure (NEXAFS) spectra from pelagic sediment from the North Atlantic gyre, South Pacific gyre, and Peru Basin from cruises KN223 (R/V Knorr), KNOX02RR (R/V Roger Revelle), and ODP leg 201 between 2002 and 2014
Carbon near edge X-ray absorption fine structure (NEXAFS) spectra from pelagic sediment from the North Atlantic gyre, South Pacific gyre, and Peru Basin from cruises KN223 (R/V Knorr), KNOX02RR (R/V Roger Revelle), and ODP leg 201 between 2002 and 2014.
false
Estes, E., Hansel, C. (2020) Carbon near edge X-ray absorption fine structure (NEXAFS) spectra from pelagic sediment from the North Atlantic gyre, South Pacific gyre, and Peru Basin from cruises KN223 (R/V Knorr), KNOX02RR (R/V Roger Revelle), and ODP leg 201 between 2002 and 2014. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2020-07-22 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.815380.1 [access date]
true
1
10.26008/1912/bco-dmo.815380.1
false
NEXAFS
carbon spectroscopy
pelagic sediment
deep biosphere
proteinaceous material
2020-07-22
Datapackage.json
Frictionless Data Package
https://www.bco-dmo.org/dataset/815380/datapackage.json
application/vnd.datapackage+json
PDF
https://www.bco-dmo.org/dataset/815380/Dataset_description.pdf
application/pdf
ISO 19115-2 (NOAA Profile)
https://www.bco-dmo.org/dataset/815380/iso
application/xml
http://www.isotc211.org/2005/gmd-noaa
Dublin Core
https://www.bco-dmo.org/dataset/815380/dublin-core
application/xml
http://purl.org/dc/elements/1.1/
815380
http://lod.bco-dmo.org/id/dataset/815380
2002 - 2014
2002
2002
2014
2014
OSPREY
http://www.opengis.net/def/crs/OGC/1.3/CRS84
<http://www.opengis.net/def/crs/OGC/1.3/CRS84> POLYGON((-165.6433 -38.0617, -50.62 -38.0617, -50.62 -38.0617, -50.62 33.4833, -165.6433 33.4833, -165.6433 -38.0617))
-165.6433
-38.0617
-50.62
33.4833
-2.289200000000
-108.131650000000
VIEW TABLE
https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_815380.htmlTable
text/html
SUBSET DATA
https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_815380.html
text/html
CSV
https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_815380.csv
text/csv
TSV
https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_815380.tsv
text/tsv
GeoJSON
https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_815380.geoJson
application/geo+json
MATLAB
https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_815380.mat
text/x-matlab
netCDF
https://erddap.bco-dmo.org/erddap/tabledap/bcodmo_dataset_815380.nc
application/x-netcdf