Metadata Report for BODC Series Reference Number 1899914
Metadata Summary
Problem Reports
Data Access Policy
Narrative Documents
Project Information
Data Activity or Cruise Information
Fixed Station Information
BODC Quality Flags
SeaDataNet Quality Flags
Metadata Summary
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Problem Reports
No Problem Report Found in the Database
Data Access Policy
Open Data supplied by Natural Environment Research Council (NERC)
You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."
Narrative Documents
Sound Profile from Cruise JC109: Instrumentation
Two Valeport MIDAS Sound Velocity Probes (serial numbers 22241 and 22355) were deployed during cruise JC109 to collect sound velocity profile data. The data from the two instruments were combined to create one sound velocity profile on the ship.
A description of the probe can be found here.
Valeport MIDAS Sound Velocity Probe
The Valeport MIDAS Sound Velocity Probe (SVP) is fitted with a time of flight sound velocity sensor, a pressure transducer and a fast response platinum resistance temperature sensor. The instrument was formerly known as the Valeport Model 650 Mk2 SVP.
Specifications
Measurement Range:
- Temperature: -5 to +35 °C
- Pressure: to a depth of 3000 or 6000 metres
- Speed of sound: 1375-1900 m.sec-1
Accuracy:
- Temperature: 0.01 °C
- Pressure: 0.01 % of range
- Speed of sound: 0.02 m.sec-1
Resolution:
- Temperature: 0.005 °C
- Pressure: 0.001 % of range
- Speed of sound: 0.001 m.sec-1
Further details can be found in the manufacturer's specification Sheet
Sound Profile from Cruise JC109: BODC Processing
Data Processing
Two instruments were used to create one sound velocity profile during cruise JC109. Both the raw and processed sound profile data were submitted to BODC as ASCII files which were archived following standard BODC procedures. The files were also accompanied by header files containing metadata. Further metadata can be found in thecruise report. The processed files were thinned by sorting the profiles into depth order and thinning the datacycles using manufacturer's editing software. The raw files were transferred to BODC internal format using standard BODC processing procedures. The thinned data are available on request.
The variables provided in the file were mapped to BODC parameter codes as follows:
| Originator's Variable | Originator's Units | BODC Parameter Code | BODC Units | Comments |
|---|---|---|---|---|
| Pressure | dbar | PRESPR01 | dbar | - |
| Sound Velocity | m s-1 | SVELVP01 | m s-1 | - |
| Temperature | °C | TEMPPR01 | °C | - |
| Date/Time | dd/mm/yyyy hh24:mi:ss | AADYAA01 | dd/mm/yyyy hh24:mi:ss | - |
Screening
Post transfer analysis and crosschecks were applied according to BODC procedures. This involved the screening of data using BODC's in house visualisation software and any suspect data were flagged but not removed.
Sound Profile from Cruise JC109: Originator's Processing
Sampling Strategy
One sound velocity profile (SVP) was conducted during cruise JC109 using Valeport Midas sound velocity probes. The profile was created using two probes simultaneously measuring from the surface to 1000m depth. The profile was used to calibrate the EM120 swath bathymetry system.
Data Processing
The raw files were downloaded from the instrument and processed using an SVP Editor. A file was produced containing the sound velocities and depths of the entire cast. This file was then thinned and then used in the EM120 and EM710 multibeam swath systems as well as the USBL system (used to track the Autosub on deployment and recovery).
Project Information
Role and extent of detachment faulting at slow-spreading mid-ocean ridges
This is a 6 year project that aims to determine (1) the sub-surface geometry and extent of the detachments beneath the ridge axis, (2) the amount and detailed distribution of magmatic crust, and (3) the asymmetry of spreading rates associated with oceanic core complexes and the volcanic seafloor.
The research aims to make an improvement in our overall understanding of the nature and geometry of ocean detachments.
This project was funded by Natural Environment Research Council parent and child grants NE/J022551/1, NE/J02029X/1, and NE/J021741/1 led by Professor Tim Reston at the University of Birmingham, Professor Christine Pierce at Durham University, and Professor Chris MacLeod at Cardiff Univserity respectively. The project is funded from April 2013 to August 2020.
Data Activity or Cruise Information
Cruise
| Cruise Name | JC109 |
| Departure Date | 2014-10-11 |
| Arrival Date | 2014-11-05 |
| Principal Scientist(s) | Christine Peirce (University of Durham, Department of Earth Sciences) |
| Ship | RRS James Cook |
Complete Cruise Metadata Report is available here
Fixed Station Information
No Fixed Station Information held for the Series
BODC Quality Control Flags
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
| Flag | Description |
|---|---|
| Blank | Unqualified |
| < | Below detection limit |
| > | In excess of quoted value |
| A | Taxonomic flag for affinis (aff.) |
| B | Beginning of CTD Down/Up Cast |
| C | Taxonomic flag for confer (cf.) |
| D | Thermometric depth |
| E | End of CTD Down/Up Cast |
| G | Non-taxonomic biological characteristic uncertainty |
| H | Extrapolated value |
| I | Taxonomic flag for single species (sp.) |
| K | Improbable value - unknown quality control source |
| L | Improbable value - originator's quality control |
| M | Improbable value - BODC quality control |
| N | Null value |
| O | Improbable value - user quality control |
| P | Trace/calm |
| Q | Indeterminate |
| R | Replacement value |
| S | Estimated value |
| T | Interpolated value |
| U | Uncalibrated |
| W | Control value |
| X | Excessive difference |
SeaDataNet Quality Control Flags
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
| Flag | Description |
|---|---|
| 0 | no quality control |
| 1 | good value |
| 2 | probably good value |
| 3 | probably bad value |
| 4 | bad value |
| 5 | changed value |
| 6 | value below detection |
| 7 | value in excess |
| 8 | interpolated value |
| 9 | missing value |
| A | value phenomenon uncertain |
| B | nominal value |
| Q | value below limit of quantification |
