http://lod.bco-dmo.org/id/dataset/915912
eng; USA
utf8
dataset
Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
2023-11-30
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Sediment core porewater and particulate measurements from three sites on the Louisiana Shelf sampled during R/V Pelican cruises from December 2021 through August 2022
2023-12-11
publication
2023-12-11
revision
BCO-DMO Linked Data URI
2023-12-11
creation
http://lod.bco-dmo.org/id/dataset/915912
Shaily Rahman
University of Colorado at Boulder
principalInvestigator
Jeffrey W. Krause
Dauphin Island Sea Lab
principalInvestigator
Lindsey R. Lemke
Dauphin Island Sea Lab
principalInvestigator
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
publisher
Cite this dataset as: Lemke, L. R., Roseburrough, R., Rahman, S., Krause, J. W. (2023) Sediment core porewater and particulate measurements from three sites on the Louisiana Shelf sampled during R/V Pelican cruises from December 2021 through August 2022. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2023-12-11 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/915912 [access date]
Sediment porewater and particulates on Louisiana Shelf Dec 2021-Aug 2022 Dataset Description: <p>This dataset&nbsp;provides information on silica cycling in coastal sediments from the Louisiana shelf region after an extreme storm event. When Hurricane Ida made landfall on August 29th, 2021, this Category 4 storm disrupted&nbsp;sediments of the proximal coastal zone and possibly altered redox and diagenetic conditions. As part of a multi-proxy approach, this data can help inform how an extreme event altered biogenic silica burial over the 10 to 12 months following the storm. Sampling for initial conditions occurred 13 days prior to the storm event from topset delta sediment. Data from this companion project can be viewed here: https://www.bco-dmo.org/dataset/945927.</p> Methods and Sampling: <p><strong>I. Field sampling</strong><br />
Sample collection took place during R/V Pelican cruises on the Louisiana Shelf in the northern part of the Gulf of Mexico.&nbsp;At each site, an 8-spot&nbsp;Ocean Instruments Multi-corer&nbsp;collected sediment that was sectioned in 2 cm intervals and placed into 50mL metal clean, acid washed tubes, pre-weighed and labeled microcentrifuge tubes for porosity, and freezer-safe Ziploc bags. Tubes were centrifuged at 3500 rpm for 10 minutes to extract and filter supernatant. The filtered supernatant was placed into a metal clean/acid washed tube and frozen for later analysis of metal and dissolved silica. The 50mL tube of sediment was frozen at -20°C for further analysis.</p>
<p><strong>II. Porewater Dissolved Constituents</strong><br />
Where there was sufficient supernatant (porewater) from the centrifuged sediment sample, it was divided for three different analyses: dissolved silica analysis (DSi), nutrient analysis (Skalar), and metal concentrations (ICPMS).&nbsp;&nbsp;</p>
<p>1. <strong><em>DSi analysis</em></strong>: 50uL of porewater was analyzed for dissolved Si(OH)<sub>4</sub>&nbsp;concentration using a spectrophotometric molybdate-blue method (Brzezinski &amp; Nelson, 1986).</p>
<p>2.&nbsp;<strong><em>Skalar Analysis (N+N, NH4, PO4)</em></strong>: Porewater was diluted with Milli‐Q (18.2 MΩ&nbsp;* cm) water and run through a Skalar Analyzer for Nitrate and Nitrite, Phosphorus, and Ammonia. For detection limits, please refer to the&nbsp;descriptions in the Parameters section below.</p>
<p>3.&nbsp;<em><strong>ICPMS (Metal Concentrations)</strong></em>: Porewater was reconstituted in dilute HNO<sub>3</sub>&nbsp;and diluted to minimize salt interferences before analysis on a Thermo Scientific Element XR High Resolution-ICP-MS housed at the University of Southern Mississippi at the Stennis Space Center. The following elements are reported in the data from the ICPMS analysis:&nbsp; magnesium (Mg), sulfur (S),&nbsp;calcium (Ca), manganese (Mn), iron (Fe), potassium (K), cesium (Cs), uranium (U), lithium (Li), vanadium (V), cobalt (Co), nickel (Ni), copper (Cu), strontium (Sr), molybdenum (Mo), barium (Ba), phosphorus (P), and aluminum (Al), along with phosphorus (P) and silica (Si).&nbsp; For each element's detection limit, please see the description in the Parameters section below.&nbsp;&nbsp;&nbsp;</p>
<p><strong>Sediments</strong><br />
Sediments were analyzed for physical properties, chemical properties, phases of silica, and isotopic composition. Each&nbsp;section below describes the specific methods in greater detail.&nbsp;&nbsp;</p>
<p><strong>III. Sediment properties</strong><br />
<em><strong>Porosity</strong></em><br />
For porosity measurements, microcentrifuge tubes were placed in a drying oven at 60°C until the sediment was dry. Once dried, tubes were weighed. Porosity was calculated as in Comeaux et al. (2012).</p>
<p><em><strong>Loss on ignition (LOI)</strong></em><br />
For loss on ignition (LOI) analysis, dried sediment was ground into a fine consistency using a mortar and pestle. Then 1g of the ground sediment was weighed into pre-muffled and pre-weighed porcelain crucibles. To remove any carbon from the presence of calcium carbonate, samples were fumed by adding 1mL of mili-Q to each crucible and placing samples into a desiccator with 10 mL of 12M HCl for 6 hours (Harris et al. 2001,&nbsp;Ramnarine et al. 2011, Walthert et al. 2010). After 6 hours, samples were placed in a vacuum oven for roughly 16 hours, until dry (Ramnarine et al. 2011, Walthert et al. 2010). Once dry, samples were kept in the oven and weighed one at a time to keep moisture out of samples. If sample was still acidic (yellow in color), 1 mL of mili-Q was added and the sample was dried again. Sediment was ground again into a fine powder.</p>
<p>After the above preparation, fumed and ground sediment was weighed (100 mg) in triplicate into pre-weighed and muffled liquid scintillation (LSC) vials. Samples were combusted at 550°C for 6 hours (Kemp et al. 2021). After combustion, weights were recorded, and loss of organic matter was calculated (Kemp et al. 2021).</p>
<p><strong>IV. Sediment Silica Pools</strong>&nbsp;&nbsp;</p>
<p><strong><em>Sequential Extractions</em>&nbsp;&nbsp;</strong><br />
Frozen samples were thawed, homogenized, and 50 mg were weighed in triplicates (per depth) into pre-labeled 50 mL centrifuge tubes (Krause et al., 2017; Pickering et al., 2020). Samples with procedural blanks (in triplicate) then went through the sequential extraction process. 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; Pickering et al., 2020).</p>
<p><strong><em>Operational Definitions</em></strong><br />
Based on prior studies, we use the following nomenclature:</p>
<p>1. <strong>Si-HCl</strong>: Mild acid-leachable pre-treatment; Highly reactive silica associated with authigenic clays and metal oxide coatings (Michalopoulos and Aller, 2004).</p>
<p>2. <strong>Si-Alk</strong>: Mild alkaline-leachable digestion completed after acid pretreatment; Frees reactive silica associated with the biogenic silica pool (Michalopoulos and Aller, 2004).</p>
<p>3. <strong>Si-NaOH (Alk)</strong>: 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 “dark bSiO<sub>2</sub>” (e.g. sponge spicules and Rhizaria).</p>
<p>4.&nbsp;<strong>tbSi</strong>: Following the traditional definition of biogenic silica (DeMaster, 1981), with no acid pre-treatment.</p>
<p>5.&nbsp;<strong>Si-NaOH (TbSi)</strong>: Harsh NaOH digestion done after T-bSi.</p>
<p><br />
<strong>V. Sediment Organic matter</strong></p>
<p><strong><em>Preparation</em></strong><br />
Same preparation as that listed above for Loss on Ignition</p>
<p><strong><em>Particulate Organic Carbon and Nitrogen content and isotopes (δ<sup>13</sup>C and δ<sup>15</sup>N)</em></strong><br />
After fumigation (explained above), ~60 to 70 mg of sediment were packed in 5x9mm silver capsules, which were then packed in tin 5x9mm capsules in triplicate (UC Davis protocol recommendation). Samples were placed in a 96 well plate and kept in a desiccator until shipped to UC Davis for isotopic (δ13C and δ15N) analysis (Krause et al. 2017).</p>
<p>Results from UC Davis had an absolute accuracy for calibrated reference materials of&nbsp;±0.04 ‰ (±0.05 ‰ SD) for δ13C and ±0.05 ‰ (±0.05 ‰ SD) for δ15N. Core depth 24-26cm was the only sample below detection (9.7ug) for δ15N, which is represented as 0 on the data sheet.</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2205277 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2205277
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2205278 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2205278
onGoing
Shaily Rahman
University of Colorado at Boulder
Campus Box 450
Institute of Arctic and Alpine Research Campus Box 450
Boulder
CO
80309-0450
USA
shaily.rahman@colorado.edu
pointOfContact
Jeffrey W. Krause
Dauphin Island Sea Lab
251-861-2141 x2289
101 Bienville Blvd
Dauphin Island
AL
36528
USA
jkrause@disl.edu
pointOfContact
Lindsey R. Lemke
Dauphin Island Sea Lab
101 Bienville Blvd.
Dauphin Island
AL
36528
USA
lindsey.r.lemke@gmail.com
pointOfContact
asNeeded
Dataset Version: 1
Unknown
Cruise
Cruise_ID
DateTime_Local
Event_number
Activity
Latitude
Longitude
Station_Number
Bottom_Depth
Core_Section_Depth
Core_Section_Mid_Depth
PW_orthosilicic_acid_avg_spec
PW_orthosilicic_acid_stdev_spec
PW_Phosphate_AA
PW_Nitrate_AA
PW_Nitrite_AA
PW_Ammonium_AA
PW_Mg_ICPMS
PW_Si_ICPMS
PW_S_ICPMS
PW_Ca_ICPMS
PW_Mn_ICPMS
PW_Fe_ICPMS
PW_K_ICPMS
PW_Cs_ICPMS
PW_U_ICPMS
PW_Li_ICPMS
PW_V_ICPMS
PW_Co_ICPMS
PW_Ni_ICPMS
PW_Cu_ICPMS
PW_Sr_ICPMS
PW_Mo_ICPMS
PW_Ba_ICPMS
PW_P_ICPMS
PW_Al_ICPMS
Sediment_Porosity_pct
Partic_Si_HCl_avg
Partic_Si_HCl_stdev
Partic_Si_Alk_avg
Partic_Si_Alk_stdev
Partic_tbSi_avg
Partic_tbSi_stdev
Partic_Si_NaOH_from_Si_Alk_avg
Partic_Si_NaOH_from_Si_Alk_stdev
Partic_Si_NaOH_from_tbSi_avg
Partic_Si_NaOH_from_tbSi_stdev
POC_d13C_avg
POC_d13C_stdev
POC_Total_C_pct_avg
POC_Total_C_pct_stdev
POC_d15N_Air_avg
POC_d15N_Air_stdev
POC_Total_N_pct_avg
POC_Total_N_pct_stdev
Particulate_Sediment_LOI_pct
ISO_DateTime_UTC
Box core
centrifuge
Skalar San++ Automated Wet Chemistry Analyzer
continuous flow interface at UC Davis
Elemental analyzer at UC Davis
Thermo Scientific Element XR high resolution inductively coupled plasma-mass spectrometer (HR-ICP-MS)
CF-IRMS at UC Davis (continuous flow isotope ratio mass spectrometer)
Ocean Instruments Multicorer
Thermo Scientific Genesys 10S UV-Vis Spectrophotometer
theme
None, User defined
cruise name
cruise_id
date_local
event
event type
latitude
longitude
station
depth_bottom
depth
depth core
Silicate, Si(OH)4, silicic acid
reactive phosphorus (PO4)
Nitrate
Nitrite
Ammonium
Magnesium
Silicon
Sulfur (S)
Calcium
Manganese
Iron
potassium
Cesium
Uranium
Lithium
Vanadium
Cobalt
Nickel
Copper
Strontium
Molybdenum
Barium
Phosphorus
Aluminum
sediment porosity
Particulate Silica
d13C
particulate organic Carbon (POC)
d15N
particulate organic nitrogen
Particulate Organic Material
ISO_DateTime_UTC
featureType
BCO-DMO Standard Parameters
Box Corer
Centrifuge
Continuous Flow Analyzer
Continuous Flow Interface for Mass Spectrometers
Elemental Analyzer
Inductively Coupled Plasma Mass Spectrometer
Isotope-ratio Mass Spectrometer
Multi Corer
Spectrophotometer
instrument
BCO-DMO Standard Instruments
PE23-05
PE22-27
PE22-20
PE22-15
service
Deployment Activity
Louisiana Shelf
place
Locations
otherRestrictions
otherRestrictions
Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use.
Collaborative Research: RAPID: Extreme disturbances/perturbations to coastal deposition systems
https://osprey.bco-dmo.org/project/905459
Collaborative Research: RAPID: Extreme disturbances/perturbations to coastal deposition systems
<p><em>NSF Award Abstract:</em><br />
This project will take advantage of the passage of Hurricane Ida across the northern Gulf of Mexico shelf in August, 2021 to study important aspects of the cycling of silica in coastal sediments. In coastal systems, water column primary productivity is dominated by diatoms, a group of phytoplankton which produce a shell of amorphous biogenic silica. This biogenic silica can either be buried in its original unaltered form or undergo chemical reactions that convert it to aluminosilicate minerals (e.g. marine clays). This latter process is important in global chemical budgets for many elements, including carbon. One of the factors that influences whether silicon is buried as biogenic silica or converted to aluminosilicates may be the amount of oxygen in the sediments. Storms mix the ocean waters and can add oxygen to sediments in shallow water, potentially changing the silica balance. The investigators collected sediment samples in early August, 2021, two weeks before Hurricane Ida. Sampling through the year after the storm will allow them to test whether storms affect silica cycling. This project will support an early-career investigator and undergraduate student researchers.</p>
<p>Tropical and subtropical coastal deposition systems sequester 25-40% of the global silica sink, a disproportionately large impact relative to their area. In the northern Gulf of Mexico seasonal water column stratification may impact how sedimentary biogenic silica is processed and preserved by limiting oxygen injections into the benthos, seasonally driving biogenic silica burial efficiency. Hurricane Ida moved through the Mississippi Delta and adjacent Louisiana shelf at the end of August 2021. Thirteen days prior to Hurricane Ida’s landfall in Port Fourchon, LA, in August 2021, the team collected sediment cores at 3 sites in the topset delta sediment between the Southwest Pass (major Mississippi River distributary) and Cocodrie, LA; all sites experienced Category 4 hurricane conditions from Ida with maximum sustained winds of 130 knots (67 m/s). Ida, a much stronger storm than either Hurricanes Harvey or Nate in 2017, likely introduced oxygen into the sediment of the proximal coastal zone, perhaps enough to turn most of the top meter or so of the sediment column oxic. The investigators hypothesize that the storm-induced change in redox and diagenetic conditions initially favored burial of biogenic silica rather than an authigenic aluminosilicate. Using a multi-proxy approach, this project will analyze how this major storm event altered biogenic silica burial over the course of ten months.</p>
<p>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.</p>
Extreme Si
largerWorkCitation
project
eng; USA
climatologyMeteorologyAtmosphere
oceans
Louisiana Shelf
-90.501
-89.012
25.501
29.218
2021-12-15
2022-08-27
Northern Gulf of Mexico, specifically the Louisiana Shelf region dominated by the discharge of the Mississippi River on the western side of the delta (28.2 to 29.1°N, -89.4 to -91.7°E)
0
BCO-DMO catalogue of parameters from Sediment core porewater and particulate measurements from three sites on the Louisiana Shelf sampled during R/V Pelican cruises from December 2021 through August 2022
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
http://lod.bco-dmo.org/id/dataset-parameter/916741.rdf
Name: Cruise
Units: unitless
Description: <p>Cruise name</p>
http://lod.bco-dmo.org/id/dataset-parameter/916742.rdf
Name: Cruise_ID
Units: unitless
Description: <p>Cruise ID</p>
http://lod.bco-dmo.org/id/dataset-parameter/916743.rdf
Name: DateTime_Local
Units: unitless
Description: <p>Local datetime of event</p>
http://lod.bco-dmo.org/id/dataset-parameter/916744.rdf
Name: Event_number
Units: unitless
Description: <p>Event number described by GMT date and time</p>
http://lod.bco-dmo.org/id/dataset-parameter/916745.rdf
Name: Activity
Units: unitless
Description: <p>Sediment collection activity for event</p>
http://lod.bco-dmo.org/id/dataset-parameter/916746.rdf
Name: Latitude
Units: decimal degrees
Description: <p>Latitude for event</p>
http://lod.bco-dmo.org/id/dataset-parameter/916747.rdf
Name: Longitude
Units: decimal degrees
Description: <p>Longitude for event</p>
http://lod.bco-dmo.org/id/dataset-parameter/916748.rdf
Name: Station_Number
Units: unitless
Description: <p>Station number of event</p>
http://lod.bco-dmo.org/id/dataset-parameter/916749.rdf
Name: Bottom_Depth
Units: meters (m)
Description: <p>Station bottom depth</p>
http://lod.bco-dmo.org/id/dataset-parameter/916750.rdf
Name: Core_Section_Depth
Units: centimeter (cm)
Description: <p>Core depth shallow and deep range for each sample collected</p>
http://lod.bco-dmo.org/id/dataset-parameter/916751.rdf
Name: Core_Section_Mid_Depth
Units: centimeter (cm)
Description: <p>Core depth median for each sample collected</p>
http://lod.bco-dmo.org/id/dataset-parameter/916752.rdf
Name: PW_orthosilicic_acid_avg_spec
Units: micromoles per liter (umol/L)
Description: <p>Average particulate dissolved silica in porewater using spectrophotometric method</p>
http://lod.bco-dmo.org/id/dataset-parameter/916753.rdf
Name: PW_orthosilicic_acid_stdev_spec
Units: micromoles per liter (umol/L)
Description: <p>Standard deviation of particulate dissolved silica in porewater using spectrophotometric method</p>
http://lod.bco-dmo.org/id/dataset-parameter/916754.rdf
Name: PW_Phosphate_AA
Units: micromoles per liter (umol/L)
Description: <p>Porewater nutrients: Phosphate measured using an autoanalyzer. Detection limit = 0.062 umol/L.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916755.rdf
Name: PW_Nitrate_AA
Units: micromoles per liter (umol/L)
Description: <p>Porewater nutrients: Nitrate measured using an autoanalyzer. Below detection (0.857 umol/L) represented as 0.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916756.rdf
Name: PW_Nitrite_AA
Units: micromoles per liter (umol/L)
Description: <p>Porewater nutrients: Nitrite measured using an autoanalyzer. Below detection (0.041 umol/L) represented as 0.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916757.rdf
Name: PW_Ammonium_AA
Units: micromoles per liter (umol/L)
Description: <p>Porewater nutrients: Ammonium measured using an autoanalyzer. Below detection = 1.704 umol/L.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916758.rdf
Name: PW_Mg_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Magnesium. Estimated detection limit = 625 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916759.rdf
Name: PW_Si_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Silicon. Estimated detection limit = 2018 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916760.rdf
Name: PW_S_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Sulfur. Estimated detection limit = 580 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916761.rdf
Name: PW_Ca_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Calcium. Estimated detection limit = 297 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916762.rdf
Name: PW_Mn_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Manganese. Estimated detection limit = 6 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916763.rdf
Name: PW_Fe_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Iron. Estimated detection limit = 20 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916764.rdf
Name: PW_K_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Potassium. Estimated detection limit = 207 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916765.rdf
Name: PW_Cs_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Cesium. Estimated detection limit = 0.01 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916766.rdf
Name: PW_U_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Uranium. Estimated detection limit = <0.01 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916767.rdf
Name: PW_Li_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Lithium. Estimated detection limit = 1.1 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916768.rdf
Name: PW_V_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Vanadium. Estimated detection limit = 0.2 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916769.rdf
Name: PW_Co_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Cobalt. Estimated detection limit = 0.2 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916770.rdf
Name: PW_Ni_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Nickel. Estimated detection limit = 0.3 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916771.rdf
Name: PW_Cu_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Copper. Estimated detection limit = 0.2 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916772.rdf
Name: PW_Sr_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Strontium. Estimated detection limit = 14 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916773.rdf
Name: PW_Mo_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Molybdenum. Estimated detection limit = 0.1 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916774.rdf
Name: PW_Ba_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Barium. Estimated detection limit = 1.9 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916775.rdf
Name: PW_P_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Phosphorus. Estimated detection limit = 8.1 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916776.rdf
Name: PW_Al_ICPMS
Units: parts per billion (ppb)
Description: <p>ICPMS derived Porewater concentration: Aluminum. Estimated detection limit = 27 ppb.</p>
http://lod.bco-dmo.org/id/dataset-parameter/916777.rdf
Name: Sediment_Porosity_pct
Units: dimensionless
Description: <p>Porosity of each core sediment sample</p>
http://lod.bco-dmo.org/id/dataset-parameter/916778.rdf
Name: Partic_Si_HCl_avg
Units: micromoles per gram (umol/g)
Description: <p>Average particulate silica after HCl leach</p>
http://lod.bco-dmo.org/id/dataset-parameter/916779.rdf
Name: Partic_Si_HCl_stdev
Units: micromoles per gram (umol/g)
Description: <p>Standard deviation of dissolved particulate silica after HCl leach</p>
http://lod.bco-dmo.org/id/dataset-parameter/916780.rdf
Name: Partic_Si_Alk_avg
Units: micromoles per gram (umol/g)
Description: <p>Particulate average of dissolved silica after Si-Alk leach</p>
http://lod.bco-dmo.org/id/dataset-parameter/916781.rdf
Name: Partic_Si_Alk_stdev
Units: micromoles per gram (umol/g)
Description: <p>Particulate standard deviation of dissolved silica after Si-Alk leach</p>
http://lod.bco-dmo.org/id/dataset-parameter/916782.rdf
Name: Partic_tbSi_avg
Units: micromoles per gram (umol/g)
Description: <p>Particulate average of dissolved silica after tbSi leach</p>
http://lod.bco-dmo.org/id/dataset-parameter/916783.rdf
Name: Partic_tbSi_stdev
Units: micromoles per gram (umol/g)
Description: <p>Particulate standard deviation of dissolved silica after tbSi leach</p>
http://lod.bco-dmo.org/id/dataset-parameter/916784.rdf
Name: Partic_Si_NaOH_from_Si_Alk_avg
Units: micromoles per gram (umol/g)
Description: <p>Particulate average of dissolved silica after Si-NaOH from Si-Alk leach material</p>
http://lod.bco-dmo.org/id/dataset-parameter/916785.rdf
Name: Partic_Si_NaOH_from_Si_Alk_stdev
Units: micromoles per gram (umol/g)
Description: <p>Particulate standard deviation of dissolved silica after Si-NaOH from Si-Alk leach material</p>
http://lod.bco-dmo.org/id/dataset-parameter/916786.rdf
Name: Partic_Si_NaOH_from_tbSi_avg
Units: micromoles per gram (umol/g)
Description: <p>Particulate average of dissolved silica after Si-NaOH from tbSi leach material</p>
http://lod.bco-dmo.org/id/dataset-parameter/916787.rdf
Name: Partic_Si_NaOH_from_tbSi_stdev
Units: micromoles per gram (umol/g)
Description: <p>Particulate standard deviation of dissolved silica after Si-NaOH from tbSi leach material</p>
http://lod.bco-dmo.org/id/dataset-parameter/916788.rdf
Name: POC_d13C_avg
Units: parts per mil (‰)
Description: <p>Average particulate organic carbon isotopic composition</p>
http://lod.bco-dmo.org/id/dataset-parameter/916789.rdf
Name: POC_d13C_stdev
Units: parts per mil (‰)
Description: <p>Standard deviation of particulate organic carbon isotopic composition</p>
http://lod.bco-dmo.org/id/dataset-parameter/916790.rdf
Name: POC_Total_C_pct_avg
Units: percent (%)
Description: <p>Average total of particulate organic carbon</p>
http://lod.bco-dmo.org/id/dataset-parameter/916791.rdf
Name: POC_Total_C_pct_stdev
Units: percent (%)
Description: <p>Standard deviation of averaged total particulate organic carbon</p>
http://lod.bco-dmo.org/id/dataset-parameter/916792.rdf
Name: POC_d15N_Air_avg
Units: parts per mil (‰)
Description: <p>Average particulate organic nitrogen isotopic composition. Below detection represented as 0 (Below detection = 9.7ug)</p>
http://lod.bco-dmo.org/id/dataset-parameter/916793.rdf
Name: POC_d15N_Air_stdev
Units: parts per mil (‰)
Description: <p>Standard deviation of particulate organic nitrogen isotopic composition</p>
http://lod.bco-dmo.org/id/dataset-parameter/916794.rdf
Name: POC_Total_N_pct_avg
Units: percent (%)
Description: <p>Average total of particulate organic nitrogen</p>
http://lod.bco-dmo.org/id/dataset-parameter/916795.rdf
Name: POC_Total_N_pct_stdev
Units: percent (%)
Description: <p>Standard deviation of averaged total particulate organic nitrogen</p>
http://lod.bco-dmo.org/id/dataset-parameter/916796.rdf
Name: Particulate_Sediment_LOI_pct
Units: percent (%)
Description: <p>Amount of organic matter lost per sediment sample</p>
http://lod.bco-dmo.org/id/dataset-parameter/916797.rdf
Name: ISO_DateTime_UTC
Units: unitless
Description: <p>Datetime of event in UTC and ISO8601 format</p>
GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
https://osprey.bco-dmo.org/dataset/915912/data/download
download
onLine
dataset
<p><strong>I. Field sampling</strong><br />
Sample collection took place during R/V Pelican cruises on the Louisiana Shelf in the northern part of the Gulf of Mexico.&nbsp;At each site, an 8-spot&nbsp;Ocean Instruments Multi-corer&nbsp;collected sediment that was sectioned in 2 cm intervals and placed into 50mL metal clean, acid washed tubes, pre-weighed and labeled microcentrifuge tubes for porosity, and freezer-safe Ziploc bags. Tubes were centrifuged at 3500 rpm for 10 minutes to extract and filter supernatant. The filtered supernatant was placed into a metal clean/acid washed tube and frozen for later analysis of metal and dissolved silica. The 50mL tube of sediment was frozen at -20°C for further analysis.</p>
<p><strong>II. Porewater Dissolved Constituents</strong><br />
Where there was sufficient supernatant (porewater) from the centrifuged sediment sample, it was divided for three different analyses: dissolved silica analysis (DSi), nutrient analysis (Skalar), and metal concentrations (ICPMS).&nbsp;&nbsp;</p>
<p>1. <strong><em>DSi analysis</em></strong>: 50uL of porewater was analyzed for dissolved Si(OH)<sub>4</sub>&nbsp;concentration using a spectrophotometric molybdate-blue method (Brzezinski &amp; Nelson, 1986).</p>
<p>2.&nbsp;<strong><em>Skalar Analysis (N+N, NH4, PO4)</em></strong>: Porewater was diluted with Milli‐Q (18.2 MΩ&nbsp;* cm) water and run through a Skalar Analyzer for Nitrate and Nitrite, Phosphorus, and Ammonia. For detection limits, please refer to the&nbsp;descriptions in the Parameters section below.</p>
<p>3.&nbsp;<em><strong>ICPMS (Metal Concentrations)</strong></em>: Porewater was reconstituted in dilute HNO<sub>3</sub>&nbsp;and diluted to minimize salt interferences before analysis on a Thermo Scientific Element XR High Resolution-ICP-MS housed at the University of Southern Mississippi at the Stennis Space Center. The following elements are reported in the data from the ICPMS analysis:&nbsp; magnesium (Mg), sulfur (S),&nbsp;calcium (Ca), manganese (Mn), iron (Fe), potassium (K), cesium (Cs), uranium (U), lithium (Li), vanadium (V), cobalt (Co), nickel (Ni), copper (Cu), strontium (Sr), molybdenum (Mo), barium (Ba), phosphorus (P), and aluminum (Al), along with phosphorus (P) and silica (Si).&nbsp; For each element's detection limit, please see the description in the Parameters section below.&nbsp;&nbsp;&nbsp;</p>
<p><strong>Sediments</strong><br />
Sediments were analyzed for physical properties, chemical properties, phases of silica, and isotopic composition. Each&nbsp;section below describes the specific methods in greater detail.&nbsp;&nbsp;</p>
<p><strong>III. Sediment properties</strong><br />
<em><strong>Porosity</strong></em><br />
For porosity measurements, microcentrifuge tubes were placed in a drying oven at 60°C until the sediment was dry. Once dried, tubes were weighed. Porosity was calculated as in Comeaux et al. (2012).</p>
<p><em><strong>Loss on ignition (LOI)</strong></em><br />
For loss on ignition (LOI) analysis, dried sediment was ground into a fine consistency using a mortar and pestle. Then 1g of the ground sediment was weighed into pre-muffled and pre-weighed porcelain crucibles. To remove any carbon from the presence of calcium carbonate, samples were fumed by adding 1mL of mili-Q to each crucible and placing samples into a desiccator with 10 mL of 12M HCl for 6 hours (Harris et al. 2001,&nbsp;Ramnarine et al. 2011, Walthert et al. 2010). After 6 hours, samples were placed in a vacuum oven for roughly 16 hours, until dry (Ramnarine et al. 2011, Walthert et al. 2010). Once dry, samples were kept in the oven and weighed one at a time to keep moisture out of samples. If sample was still acidic (yellow in color), 1 mL of mili-Q was added and the sample was dried again. Sediment was ground again into a fine powder.</p>
<p>After the above preparation, fumed and ground sediment was weighed (100 mg) in triplicate into pre-weighed and muffled liquid scintillation (LSC) vials. Samples were combusted at 550°C for 6 hours (Kemp et al. 2021). After combustion, weights were recorded, and loss of organic matter was calculated (Kemp et al. 2021).</p>
<p><strong>IV. Sediment Silica Pools</strong>&nbsp;&nbsp;</p>
<p><strong><em>Sequential Extractions</em>&nbsp;&nbsp;</strong><br />
Frozen samples were thawed, homogenized, and 50 mg were weighed in triplicates (per depth) into pre-labeled 50 mL centrifuge tubes (Krause et al., 2017; Pickering et al., 2020). Samples with procedural blanks (in triplicate) then went through the sequential extraction process. 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; Pickering et al., 2020).</p>
<p><strong><em>Operational Definitions</em></strong><br />
Based on prior studies, we use the following nomenclature:</p>
<p>1. <strong>Si-HCl</strong>: Mild acid-leachable pre-treatment; Highly reactive silica associated with authigenic clays and metal oxide coatings (Michalopoulos and Aller, 2004).</p>
<p>2. <strong>Si-Alk</strong>: Mild alkaline-leachable digestion completed after acid pretreatment; Frees reactive silica associated with the biogenic silica pool (Michalopoulos and Aller, 2004).</p>
<p>3. <strong>Si-NaOH (Alk)</strong>: 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 “dark bSiO<sub>2</sub>” (e.g. sponge spicules and Rhizaria).</p>
<p>4.&nbsp;<strong>tbSi</strong>: Following the traditional definition of biogenic silica (DeMaster, 1981), with no acid pre-treatment.</p>
<p>5.&nbsp;<strong>Si-NaOH (TbSi)</strong>: Harsh NaOH digestion done after T-bSi.</p>
<p><br />
<strong>V. Sediment Organic matter</strong></p>
<p><strong><em>Preparation</em></strong><br />
Same preparation as that listed above for Loss on Ignition</p>
<p><strong><em>Particulate Organic Carbon and Nitrogen content and isotopes (δ<sup>13</sup>C and δ<sup>15</sup>N)</em></strong><br />
After fumigation (explained above), ~60 to 70 mg of sediment were packed in 5x9mm silver capsules, which were then packed in tin 5x9mm capsules in triplicate (UC Davis protocol recommendation). Samples were placed in a 96 well plate and kept in a desiccator until shipped to UC Davis for isotopic (δ13C and δ15N) analysis (Krause et al. 2017).</p>
<p>Results from UC Davis had an absolute accuracy for calibrated reference materials of&nbsp;±0.04 ‰ (±0.05 ‰ SD) for δ13C and ±0.05 ‰ (±0.05 ‰ SD) for δ15N. Core depth 24-26cm was the only sample below detection (9.7ug) for δ15N, which is represented as 0 on the data sheet.</p>
Specified by the Principal Investigator(s)
<p>Raw data were input into Microsoft Excel (Version 2302) to calculate final reported values.</p>
<ul>
<li>Porosity was calculated as in Comeaux et al. (2012).</li>
<li>Loss of organic matter was calculated as in Kemp et al. (2021).</li>
</ul>
<p>&nbsp;</p>
Specified by the Principal Investigator(s)
- Imported data from source file "Extreme_Si_MASTER_BCODMO.xlsx" into the BCO-DMO data system.
- Added R/V Pelican official cruise IDs corresponding to the submitted cruise name.
- Combined separate date and time columns into a single datetime column
- Kept local datetime but added a column for ISO8601 formatted UTC datetime
- Removed percent (%) signs from the column values
- Modified parameter (column) names to conform with BCO-DMO naming conventions. The only allowed characters are A-Z,a-z,0-9, and underscores. Replaced spaces with underscores.
Specified by BCO-DMO Data Managers
asNeeded
7.x-1.1
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
Box core
Box core
PI Supplied Instrument Name: Box core PI Supplied Instrument Description:A box core was used on the December 2021 cruise to sample sediments Instrument Name: Box Corer Instrument Short Name:Box Corer Instrument Description: General description of a box corer:
A box corer is a marine geological tool that recovers undisturbed soft surface sediments. It is designed for minimum disturbance of the sediment surface by bow wave effects. Traditionally, it consists of a weighted stem fitted to a square sampling box. The corer is lowered vertically until it impacts with the seabed. At this point the instrument is triggered by a trip as the main coring stem passes through its frame. While pulling the corer out of the sediment a spade swings underneath the sample to prevent loss. When hauled back on board, the spade is under the box. (definition from the SeaVox Device Catalog)
Box corers are one of the simplest and most commonly used types of sediment corers. The stainless steel sampling box can contain a surface sediment block as large as 50cm x 50cm x 75cm with negligible disturbance. Once the sediment is recovered onboard, the sediment box can be detached from the frame and taken to a laboratory for subsampling and further analysis. The core sample size is controlled by the speed at which the corer is lowered into the ocean bottom. When the bottom is firm, a higher speed is required to obtain a complete sample. A depth pinger or other depth indicator is generally used to determine when the box is completely filled with sediment. Once the core box is filled with sediment, the sample is secured by moving the spade-closing lever arm to lower the cutting edge of the spade into the sediment, until the spade completely covers the bottom of the sediment box. (definition from Woods Hole Oceanographic Institution). Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/51/
centrifuge
centrifuge
PI Supplied Instrument Name: centrifuge PI Supplied Instrument Description:Mulitcorer samples were placed into tubes and centrifuged at 3500 rpm for 10 minutes to extract and filter supernatant, which was later used for dissolved silica analysis. Instrument Name: Centrifuge Instrument Short Name: Instrument Description: A machine with a rapidly rotating container that applies centrifugal force to its contents, typically to separate fluids of different densities (e.g., cream from milk) or liquids from solids.
Skalar San++ Automated Wet Chemistry Analyzer
Skalar San++ Automated Wet Chemistry Analyzer
PI Supplied Instrument Name: Skalar San++ Automated Wet Chemistry Analyzer PI Supplied Instrument Description:The Skalar San++ Automated Wet Chemistry Analyzer, also known as continuous flow analyzer, was used to analyze porewater for nitrate, nitrite, phosphorus, and ammonia. Instrument Name: Continuous Flow Analyzer Instrument Short Name:CFA Instrument Description: A sample is injected into a flowing carrier solution passing rapidly through small-bore tubing.
continuous flow interface at UC Davis
continuous flow interface at UC Davis
PI Supplied Instrument Name: continuous flow interface at UC Davis PI Supplied Instrument Description:Samples measured at University of California Davis were run on an elemental analyzer interfaced to a continuous flow isotope ratio mass spectrometer. See Stable Isotope Facility instrument descriptions here: https://stableisotopefacility.ucdavis.edu Instrument Name: Continuous Flow Interface for Mass Spectrometers Instrument Short Name: Instrument Description: A Continuous Flow Interface connects solid and liquid sample preparation devices to instruments that measure isotopic composition. It allows the introduction of the sample and also reference and carrier gases.
Examples: Finnigan MATConFlo II, ThermoScientific ConFlo IV, and Picarro Caddy.
Note: This is NOT an analyzer
Elemental analyzer at UC Davis
Elemental analyzer at UC Davis
PI Supplied Instrument Name: Elemental analyzer at UC Davis PI Supplied Instrument Description:Samples measured at University of California Davis were run on an elemental analyzer interfaced to a continuous flow isotope ratio mass spectrometer. See Stable Isotope Facility instrument descriptions here: https://stableisotopefacility.ucdavis.edu Instrument Name: Elemental Analyzer Instrument Short Name: Instrument Description: Instruments that quantify carbon, nitrogen and sometimes other elements by combusting the sample at very high temperature and assaying the resulting gaseous oxides. Usually used for samples including organic material. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB01/
Thermo Scientific Element XR high resolution inductively coupled plasma-mass spectrometer (HR-ICP-MS)
Thermo Scientific Element XR high resolution inductively coupled plasma-mass spectrometer (HR-ICP-MS)
PI Supplied Instrument Name: Thermo Scientific Element XR high resolution inductively coupled plasma-mass spectrometer (HR-ICP-MS) PI Supplied Instrument Description:Porewater was reconstituted in dilute HNO3 and diluted to minimize salt interferences before analysis on a Thermo Scientific Element XR High Resolution-ICP-MS housed at the University of Southern Mississippi at the Stennis Space Center. Instrument Name: Inductively Coupled Plasma Mass Spectrometer Instrument Short Name:ICP Mass Spec Instrument Description: 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. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB15/
CF-IRMS at UC Davis (continuous flow isotope ratio mass spectrometer)
CF-IRMS at UC Davis (continuous flow isotope ratio mass spectrometer)
PI Supplied Instrument Name: CF-IRMS at UC Davis (continuous flow isotope ratio mass spectrometer) PI Supplied Instrument Description:Samples measured at University of California Davis were run on an elemental analyzer interfaced to a continuous flow isotope ratio mass spectrometer. See Stable Isotope Facility instrument descriptions here: https://stableisotopefacility.ucdavis.edu Instrument Name: Isotope-ratio Mass Spectrometer Instrument Short Name:IR Mass Spec; IRMS Instrument Description: The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer). Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/
Ocean Instruments Multicorer
Ocean Instruments Multicorer
PI Supplied Instrument Name: Ocean Instruments Multicorer PI Supplied Instrument Description:At each site, an 8-spot Ocean Instruments Multi-corer collected sediment that was sectioned in 2 centimeter intervals Instrument Name: Multi Corer Instrument Short Name:Multi Corer Instrument 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. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/51/
Thermo Scientific Genesys 10S UV-Vis Spectrophotometer
Thermo Scientific Genesys 10S UV-Vis Spectrophotometer
PI Supplied Instrument Name: Thermo Scientific Genesys 10S UV-Vis Spectrophotometer PI Supplied Instrument Description:Porewater was analyzed for dissolved si(OH)4 concentration using a spectrophotometric molybdate-blue method and a Thermo Scientific Genesys 10S UV-Vis Spectrophotometer. Instrument Name: Spectrophotometer Instrument Short Name:Spectrophotometer Instrument Description: 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. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB20/
Cruise: PE23-05
PE23-05
R/V Pelican
Community Standard Description
International Council for the Exploration of the Sea
R/V Pelican
vessel
PE23-05
Shaily Rahman
University of Colorado at Boulder
Cruise: PE22-27
PE22-27
R/V Pelican
Community Standard Description
International Council for the Exploration of the Sea
R/V Pelican
vessel
PE22-27
Shaily Rahman
University of Colorado at Boulder
Cruise: PE22-20
PE22-20
R/V Pelican
Community Standard Description
International Council for the Exploration of the Sea
R/V Pelican
vessel
PE22-20
Shaily Rahman
University of Colorado at Boulder
Cruise: PE22-15
PE22-15
R/V Pelican
Community Standard Description
International Council for the Exploration of the Sea
R/V Pelican
vessel
PE22-15
Jeffrey W. Krause
Dauphin Island Sea Lab
R/V Pelican
Community Standard Description
International Council for the Exploration of the Sea
R/V Pelican
vessel