Dataset: sediment_cores
Deployment: LDZ10

Results of Sediment Core Experiments in Chesapeake Bay

Principal Investigator:

Dr Byron C Crump (University of Maryland Center for Environmental Science, UMCES/HPL)

BCO-DMO Data Manager:

Ms Dicky Allison (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Life in the Dead Zone: Microbial respiration, production, diversity and gene expression in seasonally anoxic estuarine waters (LiDZ)

Current State:

Final no updates expected

Version:

final

Version Date:

2014-07-09

Data URL:

https://www.bco-dmo.org/dataset-deployment/518485/data

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Description

Sediment core data with accompanying environmental measurements from the middle region of the Chesapeake Bay, in seasonally anoxic bottom waters, collected in spring and summer of 2010-2011.

Core samples and sensor-based measurements were made during sixteen research cruises in 2010-2012: two 1-week cruises aboard the UNOLS vessel R/V Hugh R. Sharp, and fourteen 1-day cruises aboard the R/V Terrapin, which is a 25' Parker outboard motorboat with davit for deploying a CTD package.

Methods & Sampling

Dataset acquisition description

Sediment cores were collected with an acrylic/PVC Soutar-design box corer to determine sediment-water fluxes.
The sediment was sub-cored using two 7×30 cm (inner diameter × height) acrylic cylinders to a depth of ~15 cm.
Sediment and water column blank cores were preincubated in a temperature-controlled walk-in chamber or
incubator at bottom water temperatures (±1 °C) for 6 h for oxic conditions and overnight for anoxic
conditions to allow any initial core disturbance artifacts to dissipate. Each core was equipped with a
Teflon magnetic stir bar rotating at 20 rpm to mix overlying water without resuspension. Overlying water was
collected four times during 4-6 hour incubations (oxic) or 24 h incubations (anoxic): gas and solute samples
were collected in triplicate 6 ml Exetainer vials and 20 ml syringes, respectively. During each subsampling,
<5 % water volume in each core was replaced with collected bottom water through a second port so that no
bubbles formed within the tubes. Sediment-water fluxes were calculated using linear regressions of gas or
solute concentrations and the slopes of blank cores were used to account for water column processes.

Data Processing Description

Dataset Processing Description

Because sediment processing proceeded along with water column processing, see

SAMPLE ANALYSES

References:

Lane, L., Rhoades, S., Thomas, C., Van Heukelem, L. 2000. Standard Operating Procedures. Horn Point Laboratory Technical Report No. TA-264-00.

Brewer, P. G. and D. W. Spencer. 1971. Colorimetric Determination of Manganese in Anoxic Waters. Limnology And Oceanography 16:107-110.

Parsons, T. R., Y. Maita, and C. M. Lalli. 1984. A manual of chemical and biological methods for seawater analysis. Pergamon Press, Oxford.

Arar, E. J., Collins, G. B., 1997. In Vitro Determination of chlorophyll a and pheophytin a in marine and freshwater algae by fluorescence. Method 445.0. U.S. Environmental Protection Agency.

DMO notes:

Format or vocabulary adjustments to metadata primarily involved controlling the vocabulary and adding UNOLS names for the cruises.
Date changed to date_local
Time -> time_local
Cruise -> cruise [Inserted cruise_new to give column for UNOLS name]
Lowercase Cast, Depth

Changed modifier from cruise name to cast and called new column cast_new (e.g. LDZ8_NO3 to LDZ8 and Channel_NO3).
Abbreviated Latitude, Longiture, Conductivity, Temperature, Salinity, Fluorescence
Decoded Oxygen1 -> O2_conc and Oxygen2 -> O2_rate

In keeping with BCO-DMO best practices, ISODateTime has been added as a formatted time column. At this time it is local time.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-0961920	NSF Division of Ocean Sciences

Instruments

Box Corer

Supplied Description:

Acrylic/PVC Soutar-design box corer. (Andy Soutar, Scripps)

Instrument Type

Generic Name: Box Corer

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/51/

Generic 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).

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
cruise	Internal cruise number	text	cruise_name
cruise_new	UNOLS cruise identifier	text	cruise_name
cast	where in the bay strata the core was collected	text	cast
cast_new	location in the bay geography where the core was collected plus Nitrate	text	cast
date_local	Date	Eastern Daylight Time	date
time_local	HH:MM	24-hour clock	time
depth	Sampling depth	meters	depth
lat	Latitude	decimal degrees	lat
lon	Longitude	decimal degrees	lon
cond	Conductivity: Measured with a SBE 25 on the R/V Terrapin and SBE 911plus on R/V Hugh R. Sharp; Sea-Bird Electronics	microsiemens per centimeter	cond
temp	Temperature: Measured with a SBE 25 on the R/V Terrapin and SBE 911plus on R/V Hugh R. Sharp; Sea-Bird Electronics	degrees celsius	temp
sal	Salinity: Measured with a SBE 25 on the R/V Terrapin and SBE 911plus on R/V Hugh R. Sharp; Sea-Bird Electronics	salinity	sal
O2_conc	oxygen concentration: Measured with a SBE 25 on the R/V Terrapin and SBE 911plus on R/V Hugh R. Sharp; Sea-Bird Electronics	milligrams per liter	O2_ml_L
O2_sat	oxygen saturation: Measured with a SBE 25 on the R/V Terrapin and SBE 911plus on R/V Hugh R. Sharp; Sea-Bird Electronics	percent saturation	O2_sat_pcnt
fluor	Fluorescence: Measured with a WETStar sensor; WET Labs	milligrams per cubic meter	fluor
N2_flux	Nitrogen flux; micromoles per meter square hour; Sediment-water flux is calculated using a linear regression of concentrations and the slope of blank core is used to account for water column processes	umol N2-N/m2/h	no_bcodmo_term
O2_flux	Oxygen flux; micromoles per meter square hour; Measured with membrane inlet mass spectrometer	umol/m2/h	no_bcodmo_term
DIC_flux	Dissolved inorganic carbon flux; micromoles per meter square hour; Measured with an infrared CO2 detector	umol/m2/h	no_bcodmo_term
NOx_flux	Nitrite + Nitrate flux; micromoles per meter square hour; Measured colorimetrically (Brewer and Spencer 1971; Parsons et al. 1984)	umol/m2/h	no_bcodmo_term
NH4_flux	Ammonium flux; micromoles per meter square hour; Measured colorimetrically (Brewer and Spencer 1971; Parsons et al. 1984)	umol/m2/h	no_bcodmo_term
SRP_flux	Soluble reactive phosphorous flux; micromoles per meter square hour; Measured colorimetrically (Brewer and Spencer 1971; Parsons et al. 1984)	umol/m2/h	no_bcodmo_term
H2S_flux	Total dissolved sulfide (DS = [S2-] + [HS-] + [H2S]) flux; micromoles per meter square hour; Measured colorimetrically (Brewer and Spencer 1971; Parsons et al. 1984)	umol/m2/h	no_bcodmo_term
H2Spw01	Total dissolved sulfide (DS = [S2-] + [HS-] + [H2S]); micromolar; Total dissolved sulfide concentration in pore water. Number following pw (pore water) indicates sampling depth in sediment (e.g: 01: centimeter from 0 to 1 cm)	uM	no_bcodmo_term
H2Spw12	Total dissolved sulfide (DS = [S2-] + [HS-] + [H2S]); micromolar; Total dissolved sulfide concentration in pore water. Number following pw (pore water) indicates sampling depth in sediment (e.g: 12: centimeter from 1 to 2 cm)	uM	no_bcodmo_term
H2Spw24	Total dissolved sulfide (DS = [S2-] + [HS-] + [H2S]); micromolar; Total dissolved sulfide concentration in pore water. Number following pw (pore water) indicates sampling depth in sediment (e.g: 24: centimeter from 2 to 4 cm)	uM	no_bcodmo_term
H2Spw46	Total dissolved sulfide (DS = [S2-] + [HS-] + [H2S]); micromolar; Total dissolved sulfide concentration in pore water. Number following pw (pore water) indicates sampling depth in sediment (e.g: 46: centimeter from 4 to 6 cm)	uM	no_bcodmo_term
H2Spw68	Total dissolved sulfide (DS = [S2-] + [HS-] + [H2S]); micromolar; Total dissolved sulfide concentration in pore water. Number following pw (pore water) indicates sampling depth in sediment (e.g: 68: centimeter from 6 to 8 cm)	uM	no_bcodmo_term
H2Spw810	Total dissolved sulfide (DS = [S2-] + [HS-] + [H2S]); micromolar; Total dissolved sulfide concentration in pore water. Number following pw (pore water) indicates sampling depth in sediment (e.g: 810: centimeter from 8 to 10 cm)	uM	no_bcodmo_term
ISO_DateTime_Local	ISO8601-compliant date/time standard	YYYY-mm-ddTHH:MM:SS.ss	ISO_DateTime_Local

Database

Contribute Data

Dataset: sediment_cores
Deployment: LDZ10

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: sediment_coresDeployment: LDZ10

Dataset acquisition description

Dataset Processing Description

Dataset: sediment_cores
Deployment: LDZ10