Download URLhttps://www.bco-dmo.org/dataset/757722/data/download
Media Type text/tab-separated-values
Created March 6, 2019
Modified March 7, 2019
State Final no updates expected
Brief Description

CTD data from AT39-01 (North Pond 2017 expedition)

Acquisition Description

Software Version Seasave V 7.23.2

Processing Description

BCO-DMO Processing Notes:
– combined all files into one large file
– reformatted latitude and longitude into degrees
– reformatted date/time to ISO 8601 format
– appended lat, lon, time_ut, cast_id, and cast_no to the data from the headers
– added conventional header with dataset name, PI name, version date
– sorted by date/time and depth


Sea-Bird SBE 9 [CTD Sea-Bird SBE 911plus]
Instance Description (Sea-Bird SBE 9)

Sea-Bird SBE 9 Data File

The Sea-Bird SBE 911plus is a type of CTD instrument package for continuous measurement of conductivity, temperature and pressure. The SBE 911plus includes the SBE 9plus Underwater Unit and the SBE 11plus Deck Unit (for real-time readout using conductive wire) for deployment from a vessel. The combination of the SBE 9plus and SBE 11plus is called a SBE 911plus. The SBE 9plus uses Sea-Bird's standard modular temperature and conductivity sensors (SBE 3plus and SBE 4). The SBE 9plus CTD can be configured with up to eight auxiliary sensors to measure other parameters including dissolved oxygen, pH, turbidity, fluorescence, light (PAR), light transmission, etc.). more information from Sea-Bird Electronics
WET Labs C Star [Wet Labs CSTAR Transmissometer]
Instance Description (WET Labs C Star)

WET Labs C Star
serial number: CST-854DR
caibration date: 8-Dec-16

A highly integrated opto-electronic design to provide a low cost, compact solution for underwater measurements of beam transmittance. The instrument is capable of either free space measurements, or through the use of an optical flow tube, flow-through sampling with a pump. It can be used in profiling, moored, or underway applications. more information from Wet Labs
WET Labs ECO-AFL/FL [Wet Labs ECO-AFL/FL Fluorometer]
Instance Description (WET Labs ECO-AFL/FL)

Serial No.: FLTURT-964
Calibration Date: 22-Nov-16

The Environmental Characterization Optics (ECO) series of single channel fluorometers delivers both high resolution and wide ranges across the entire line of parameters using 14 bit digital processing. The ECO series excels in biological monitoring and dye trace studies. The potted optics block results in long term stability of the instrument and the optional anti-biofouling technology delivers truly long term field measurements. more information from Wet Labs
Instance Description (WET Labs, ECO-NTU)

Serial no.: FLTURT-964
Calibration date: 22-Nov-16

The ECO FLNTU is a dual-wavelength, single-angle sensor for simultaneously determining both chlorophyll fluorescence and turbidity.


press [pressure]
Pressure. Originally named 'prDM'.
water pressure at measurement; depth reported as pressure; positive number increasing with water depth
temp [temperature]
Primary temperature measurement. Originally named 't090C'.
water temperature at measurement depth
temp_2 [temperature]
Secondary tempearture measurement. Originally named 't190C'.
water temperature at measurement depth
cond [conductivity]
Primary conductivity measurement. Originally named 'c0S/m'.

Conductivity.  Units and collection methods may vary.  Often reported in Siemens/meter.

When used in a JGOFS/GLOBEC project this is the conductivity in Siemens/meter for the primary conductivity sensor on a CTD.

cond_2 [conductivity]
Secondary conductivity measurement. Originally named 'c1S/m'.

Conductivity.  Units and collection methods may vary.  Often reported in Siemens/meter.

When used in a JGOFS/GLOBEC project this is the conductivity in Siemens/meter for the primary conductivity sensor on a CTD.

trans [transmission]
Beam transmission expressed as percent. Originally named 'CStarTr0'.

light transmission, as percent

fluor [fluorescence]
Fluorescence measured by WET Labs ECO-AFL/FL in milligrams per cubic meter. Originally named 'flECO-AFL'.

Fluorescence. Indirect measure of pigment concentration.

Units and collection method may vary. Units often reported in milligrams/meter^3 (mg/m3) or micromoles per liter (ug/L). Sometimes reported after being calibrated against extracted pigment concentrations.

In JGOFS/GLOBEC projects fluorescence is measured from CTD instrument sensor.

turbidity [turbidity]
Turbidity measured by WET Labs ECO. Originally named 'turbWetntu0'.

Turbidity is the cloudiness or haziness of a fluid caused by individual particles

Raw voltage from SBE43 oxygen sensor. Originally named 'Sbeox0V'.

dissolved oxygen concentration

depth [depth]

Depth. Originally named 'depSM'.

Observation/sample depth below the sea surface. Units often reported as: meters, feet.

When used in a JGOFS/GLOBEC dataset the depth is a best estimate; usually but not always calculated from pressure; calculated either from CTD pressure using Fofonoff and Millard (1982; UNESCO Tech Paper #44) algorithm adjusted for 1980 equation of state for seawater (EOS80) or simply equivalent to nominal depth as recorded during sampling if CTD pressure was unavailable.

density [density]
Primary measure of density in kilograms per cubic meter. Originally named 'density00'.

density, in mass per unit volume

density_2 [density]
Secondary measure of density in kilograms per cubic meter. Originally named 'density11'.

density, in mass per unit volume

sal [sal]
Primary salinity measurement. Originally named 'sal00'.

salinity, calculated from the CTD 'primary sensors' of conductivity and temperature, Practical Salinity Scale (PSS-78), dimensionless. Depending on the input source, salinity from the primary sensors can have a variety of names i.e. s0, s00, sal0, sal00.

sal_2 [sal]
Secondary salinity measurement. Originally named 'sal11'.

salinity, calculated from the CTD 'primary sensors' of conductivity and temperature, Practical Salinity Scale (PSS-78), dimensionless. Depending on the input source, salinity from the primary sensors can have a variety of names i.e. s0, s00, sal0, sal00.

sound_vel [sound_vel]
Sound velocity in meters per second. Originally named 'svCM'.

sound velocity in sea water, in meters/second

sound_vel_2 [sound_vel]
Sound velocity in meters per second from secondary sensor. Originally named 'svCM1'.

sound velocity in sea water, in meters/second


Oxygen concentration from SBE 43. Originally named 'sbeox0Mm/L'.

dissolved oxygen concentration

flag [flag]
Quality flag; bad flag = -9.99e-29.

Data flag. Multiple uses which are dataset dependent. Some uses: data quality, collection occurance or success, depth indicator. See dataset documentation for specific details

time_utc [ISO_DateTime_UTC]

date and time in ISO 8601 format yyyy-m-ddTHH:MM:SS

Date/Time (UTC) ISO formatted
This standard is based on ISO 8601:2004(E) and takes on any of the following forms:
2009-08-30T09:05:00[.xx] (local time)
2009-08-30T14:05:00[.xx]Z (UTC time)
The dashes and the colons can be dropped.
The T can also be dropped "by mutual agreement", but one needs the trailing Z if the time is UTC.

Sample ISO_datetime_utc:
2009-08-30T14:05:00[.xx]Z (UTC time)

Format: YYYY-mm-ddTHH:MM:SS[.xx]Z (UTC time)
cast_id [cast]
identifier for the cast

cast or profile number

cast_no [cast]
number for the cast

cast or profile number

Dataset Maintainers

Grieg StewardUniversity of Hawaii at Manoa (SOEST)
Mathew BiddleWoods Hole Oceanographic Institution (WHOI BCO-DMO)

BCO-DMO Project Info

Project Title Collaborative Research: Completing North Pond Borehole Experiments to Elucidate the Hydrology of Young, Slow-Spread Crust
Acronym North Pond 2017
Created July 5, 2017
Modified July 5, 2017
Project Description

NSF Award Abstract:
Seawater circulates through the upper part of the oceanic crust much like groundwater flows through continental aquifers. However, in the ocean this seawater circulation, many times heated by buried magmatic bodies, transports and releases 25% of the Earth’s heat. The rate of fluid flow through ocean crust is estimated to be equal to the amount of water delivered by rivers to the ocean. Much of what we know of this subseafloor fluid flow comes from studies in the eastern Pacific Ocean on ocean crust created by medium and fast spreading mid-ocean ridges. These studies indicate that seawater and its circulation through the seafloor significantly impact crustal evolution and biogeochemical cycles in the ocean and affect the biosphere in ways that are just now beginning to be quantified and understood. To expand this understanding, this research focuses on fluid flow of seafloor generated by slow spreading ridges, like those in the Atlantic, Indian and Arctic Oceans because it is significantly different in structure, mineralogy, and morphology than that formed at fast and intermediate spreading ridges. This research returns to North Pond, a long-term; seafloor; fluid flow monitoring site, drilled and instumented by the Ocean Drilling Program in the Atlantic Ocean. This research site was punctured by boreholes in which fluid flow and geochemical and biological samplers have been deployed for a number of years to collect data and samples. It also provides resources for shipboard and on-shore geochemical and biological analysis. Broader impacts of the work include sensor and technology development, which increases infrastructure for science and has commercial applications. It also provides training for students and the integration of education and research at three US academic institutions, one of which is an EPSCoR state (Mississippi), and supports a PI whose gender is under-represented in sciences and engineering. Public outreach will be carried out in conjunction with the Center for Dark Energy Biosphere Investigations.

This project completes a long-term biogeochemical and hydrologic study of ridge flank hydrothermal processes on slow-spreading, 8 million year old crust on the western flank of the Mid-Atlantic Ridge. The site, North Pond, is an isolated northeast-trending sediment pond, bounded by undersea mountains that have been studied since the 1970s. During Integrated Ocean Drilling Program Expedition 336 in 2011 and an expedition five months later (2012), sensors, samplers, and experiments were deployed in four borehole observatories drilled into the seafloor that penetrated into volcanic crust, with the purpose of monitoring changes in hydrologic properties, crustal fluid composition and mineral alteration, among other objectives. Wellhead sampling in 2012 and 2014 already revealed changes in crustal fluid compositions; and associated pressure data confirm that the boreholes are sealed and overpressured, reflecting a change in the formation as the boreholes recover from drilling disturbances. This research includes a 13-day oceanographic expedition and use of on-site robotically operated vehicles to recover downhole instrument packages at North Pond. It will allow the sampling of crustal fluids, recovering pressure data, and measuring fluid flow rates. Ship- and shore-based analyses will be used to address fundamental questions related to the hydrogeology of hydrothermal processes on slow-spread crust.

Data Project Maintainers
Beth N. OrcuttBigelow Laboratory for Ocean SciencesLead Principal Investigator
Charles Geoffrey WheatUniversity of Alaska Fairbanks (UAF-IMS)Principal Investigator
Keir BeckerUniversity of Miami Rosenstiel School of Marine and Atmospheric Science (UM-RSMAS)Principal Investigator

BCO-DMO Project Info

Project Title Collaborative Research: A multidimensional approach to understanding microbial carbon cycling beneath the seafloor during cool hydrothermal circulation
Acronym Subseafloor Microbial Carbon Cycling
Created June 24, 2016
Modified November 29, 2017
Project Description

NSF abstract:

The global ocean comprises Earth’s largest microbiome, with at least half of the ocean’s microbial biomass occurring beneath the ocean floor. In particular, oceanic crust encompasses the largest aquifer on Earth, with a liquid volume equal to approximately 2% of the ocean’s volume. It also harbors a substantial reservoir of microbial life that may influence global-scale biogeochemical cycles. This project investigates this largest actively flowing aquifer system on Earth- the fluids circulating through oceanic crust underlying the oceans and sediments. Despite advancing knowledge about life in the deep ocean, the understanding of microorganisms in the rocky oceanic crust and the fluids flowing through it remains rudimentary. This project is focused on understanding the linkages between microbial activity and the cycling of carbon in the cool, subseafloor biosphere. The balance between organic carbon-consuming and organic carbon-producing metabolisms within the crustal biosphere will be determined using seafloor observatories put in place by the International Ocean Discovery Program (IODP) on the flanks of the Mid-Atlantic Ridge, likely representative of the majority of global hydrothermal fluid circulation. The rates of microbial transformations of carbon will be determined using both geochemical and biological approaches. Results will help establish the extent to which microbially-mediated processes in the subseafloor influence carbon cycling in the ocean. This work will represent the first comprehensive description of carbon cycling in the cold oxic crustal aquifer. Two female postdocs will be supported on the grant, and both high school and community college students will also be involved through collaborations with Cape Cod Community College and Cambridge-Rindge and Latin School. The goal is to promote science, technology, engineering and math literacy among high-school and community college students through hand-on research experiences, peer-to-peer mentoring, and professional development opportunities. 

The goal of the project is to answer the question “is the cool crustal subseafloor biosphere net autotrophic or net heterotrophic?” 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. The two objectives of the project are to:

1. Characterize suspended particles in subseafloor fluids with respect to their inorganic and organic carbon content, and natural 14C and 13C isotopic ratios, to determine microbially-mediated fluxes and processes.

2. Characterize the net influence of particle-associated and free-living microbial communities on subseafloor fluid primary production and remineralization, as well as the taxon-specific contributions to these same processes.

The integration of isotope geochemical and molecular biological approaches represents a significant cross-disciplinary advance in the understanding of the microbial ecology and geochemistry of the subseafloor biosphere in young oceanic crust and their role in maintaining global deep-sea redox balance. Expected outcomes include identifying signatures of autotrophic and heterotrophic metabolism in particle-associated and free-living subseafloor microbial communities as well as quantification of autotrophic and heterotrophic metabolism and associated taxon-abundances to provide insights into the net and specific microbial processes in crustal fluids on carbon fluxes.

Data Project Maintainers
Julie A. HuberWoods Hole Oceanographic Institution (WHOI)Lead Principal Investigator
Peter R. GirguisHarvard UniversityPrincipal Investigator