URLhttps://www.bco-dmo.org/dataset/630362
Download URLhttps://www.bco-dmo.org/dataset/630362/data/download
Media Typetext/tab-separated-values
CreatedDecember 30, 2015
ModifiedAugust 19, 2016
Brief DescriptionDissolved organic carbon and total dissolved nitrogen from the formation fluids recovered from the CORKs installed at the North Pond in 2012.

Acquisition Description

Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) were measured by high temperature (680 ºC) combustion using a Shimadzu TOC-L analyzer at the SOEST Laboratory for Analytical Biogeochemistry, University of Hawaii. Samples analyzed include those filtered in situ for crustal fluids as well as the CTD samples filtered on deck. Samples were acidified to pH <2 within the autosampler syringe and were purged with nitrogen to remove inorganic carbon. Five to six replicate analyses were performed using an injected sample volume of 150 μL. The detection limits of DOC and TDN were about 2 and 1.5 uM, respectively. Two consensus reference materials CRM, from University of Miami, deep seawater and low carbon water, were used extensively before, between, and after sample analysis to monitor analytical accuracy. The analytical reproducibility for DOC and TDN is better than 1.1 uM and 460 0.2 uM, respectively, by repeated analysis of four deep seawater CRM.

Processing Description

BCO-DMO Processing:
- Modified parameter names to conform with BCO-DMO naming conventions;
- Replaced commas with semi-colons;
- Replaced spaces with underscores;
- Added cruise id numbers.

Instruments

Shimadzu TOC-L analyzer [Shimadzu TOC-L Analyzer]
Details
Instance Description (Shimadzu TOC-L analyzer)

Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) were measured by high temperature (680 degrees C) combustion using a Shimadzu TOC-L analyzer at the SOEST Laboratory for Analytical Biogeochemistry, University of Hawaii.

A Shimadzu TOC-L Analyzer measures DOC by high temperature combustion method.

Developed by Shimadzu, the 680 degree C combustion catalytic oxidation method is now used worldwide. One of its most important features is the capacity to efficiently oxidize hard-to-decompose organic compounds, including insoluble and macromolecular organic compounds. The 680 degree C combustion catalytic oxidation method has been adopted for the TOC-L series.

http://www.shimadzu.com/an/toc/lab/toc-l2.html

Parameters

UH_Cowen_ID [sample]
Details
UH_Cowen_ID

UH_Cowen identification number.

unique sample identification or number; any combination of alpha numeric characters; precise definition is file dependent

cruise_id [cruise_id]
Details
cruise_id
Cruise identifier.
cruise designation; name
site [site]
Details
site
Sampling site name. The nomenclature refers to the IODP hole and formation horizon. For example, U1383C-shallow means the fluids came from IODP CORK drillhole 1383C in the shallowest accessible porewater horizon.
Sampling site identification.
dive_num [unknown]
Details
dive_num
Dive number.
association with a community-wide standard parameter is not yet defined
date [date]
Details
date
Year-month-day.

date; generally reported in GMT as YYYYMMDD (year; month; day); also as MMDD (month; day); EqPac dates are local Hawaii time. ISO_Date format is YYYY-MM-DD (http://www.iso.org/iso/home/standards/iso8601.htm)

DOC [DOC]
Details
DOC
Dissolved organic carbon.
dissolved organic Carbon
TDN
Total dissolved nitrogen.

The concentration of nitrogen remaining in a seawater sample after all particulate nitrogen has been removed by filtration. See dataset for units (may be micromoles/kilogram or micromolar).

Dataset Maintainers

NameAffiliationContact
Peter R. GirguisHarvard University
Julie A. HuberMarine Biological Laboratory (MBL)
Brian T. GlazerUniversity of Hawaii at Manoa (SOEST)
Beate KraftHarvard University
Shannon RauchWoods Hole Oceanographic Institution (WHOI BCO-DMO)

BCO-DMO Project Info

Project TitleCollaborative Research: Characterization of Microbial Transformations in Basement Fluids, from Genes to Geochemical Cycling
AcronymNorth Pond Microbes
URLhttps://www.bco-dmo.org/project/554914
CreatedApril 3, 2015
ModifiedAugust 29, 2019
Project Description

Description from NSF award abstract:
Current estimates suggest that the volume of ocean crust capable of sustaining life is comparable in magnitude to that of the oceans. To date, there is little understanding of the composition or functional capacity of microbial communities in the sub-seafloor, or their influence on the chemistry of the oceans and subsequent consequences for global biogeochemical cycles. This project focuses on understanding the relationship between microbial communities and fluid chemistry in young crustal fluids that are responsible for the transport of energy, nutrients, and organisms in the crust. Specifically, the PIs will couple microbial activity measurements, including autotrophic carbon, nitrogen and sulfur metabolisms as well as mineral oxide reduction, with quantitative assessments of functional gene expression and geochemical transformations in basement fluids. Through a comprehensive suite of in situ and shipboard analyses, this research will yield cross-disciplinary advances in our understanding of the microbial ecology and geochemistry of the sub-seafloor biosphere. The focus of the effort is at North Pond, an isolated sediment pond located on ridge flank oceanic crust 7-8 million years old on the western side of the Mid-Atlantic Ridge. North Pond is currently the target for drilling on IODP expedition 336, during which it will be instrumented with three sub-seafloor basement observatories.

The project will leverage this opportunity for targeted and distinct sampling at North Pond on two German-US research cruises to accomplish three main objectives:

1. to determine if different basement fluid horizons across North Pond host distinct microbial communities and chemical milieus and the degree to which they change over a two-year post-drilling period.

2. to quantify the extent of autotrophic metabolism via microbially-mediated transformations in carbon, nitrogen, and sulfur species in basement fluids at North Pond.

3. to determine the extent of suspended particulate mineral oxides in basement fluids at North Pond and to characterize their role as oxidants for fluid-hosted microbial communities.

Specific outcomes include quantitative assessments of microbial activity and gene expression as well as geochemical transformations. The program builds on the integrative research goals for North Pond and will provide important data for guiding the development of that and future deep biosphere research programs. Results will increase understanding of microbial life and chemistry in young oceanic crust as well as provide new insights into controls on the distribution and activity of marine microbial communities throughout the worlds oceans.

There are no data about microbial communities in ubiquitous cold, oceanic crust, the emphasis of the proposed work. This is an interdisciplinary project at the interface of microbial ecology, chemistry, and deep-sea oceanography with direct links to international and national research and educational organizations.

Project Maintainers
NameAffiliationRoleContact
Julie A. HuberMarine Biological Laboratory (MBL)Lead Principal Investigator
Peter R. GirguisHarvard UniversityPrincipal Investigator
Brian T. GlazerUniversity of Hawaii at Manoa (SOEST)Principal Investigator
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