(2017). Array of Ocean Bottom Tilt Current Meters: data from the EMSO-Azores observatory, 2016-2017. SEANOE. https://doi.org/10.17882/74195
Copy this text
Array of Ocean Bottom Tilt Current Meters: data from the EMSO-Azores observatory, 2016-2017
This dataset contains current data acquired between September 2016 and July 2017 using 2 TCM3 Ocean Bottom Tilt Current Meters installed next to the Tour Eiffel and Montségur hydrothermal vent sites.
The TCM-3 Ocean Bottom Tilt Current Meter from Lowell Instruments LLC (North Falmouth, MA, USA) measures current using the drag-tilt principle. The logger is buoyant and is anchored to the bottom via a short flexible tether. Drag from moving water tilts the logger in the direction of flow. The logger’s accelerometer and magnetometer channels are used to record the amount of tilt and direction of tilt (compass bearing). The array comprised 3 currentmeters, deployed near the Tour Eiffel, Montségur and White Castle hydrothermal vent sites (the instrument at White Castle did not recover data). The array is not connected to an energy node. The currentmeter's internal clocks are set to UTC time before deployment. Clock drift after recovery is not implemented in data but added as metadata in the file "Sites and Sensor metadata".
Keywords
Mid-Atlantic Ridge, EMSO-Azores, EMSO, Hydrothermal Vents, Lucky Strike, Eiffel Tower, Crystal, Montsegur, current velocity, current direction, near seafloor seawater temperature, Time-series, MoMARSAT2017, MoMARSAT2016
Location
37.30134N, 37.2888S, -32.275618E, -32.27982W
Devices
Parameters
- temperature (°C)
- current velocity (m/s)
- current direction (° from N)
Location
- Regional node: Emso-Azores
- Site: Lucky Strike hydrothermal field
- coordinates: see Table_TCM3EMSO_Azores 2016-2017
Installation
- cruise: CANNAT Mathilde, SARRADIN Pierre-Marie (2016) MOMARSAT2016 cruise, RV L'Atalante, https://doi.org/10.17600/16001200
Recovery
- Cruise: SARRADIN Pierre-Marie, CANNAT Mathilde (2017) MOMARSAT2017 cruise, RV Pourquoi pas ?, http://dx.doi.org/10.17600/17000500
Operating parameters
For deployments near selected hydrothermal vents at the EMSO-Azores observatory, the accelerometer and magnetometer are configured with a burst interval of 1 minute, a burst rate of 8 Hz and a burst duration of 15 seconds. Temperature are recorded with a period of 1 minute.
Sensor metadata
The specifications of the magnetometer, accelerometer and temperature probes are as follows:
- magnetometer: 3-axis magnetoresistive sensor and 12-bit A/D Converter, range +/- 1.3 Gauss, accuracy +/- 1° typical (nominal compass bearing), resolution < 0.001 Gauss, maximum recording rate 64 Hz, measurement duration 6 mS
- accelerometer: 3-axis MEMS Accelerometer and 10-bit A/D Converter, software averaging: up to 32 values per measurement (25 samples per measurement are averaged when recording at 64 Hz), range +/- 2 g, accuracy < 0.01 g (enables 1° inclination determination), resolution < 0.001 g, maximum recording rate 64 Hz, measurement duration 0.625 ms per sample, 32 samples per recorded value (15.6 ms total sample time at 64 Hz 20 ms at 32 Hz or less)
- thermistor: NTC Thermistor and 16-bit A/D Converter, low-pass filter rejects 50/60 Hz noise, range -5 to 30 °C (standard), -20 to 50 °C (extended), accuracy +/-0.1 °C (standard), +/-0.2 °C (extended), resolution < 0.01 °C, maximum rate 1 Hz, time constant 4 minutes typical (when plunged into an ice bath).
Sensor setup
Test and calibration A set of calibration coefficients for the magnetometer, accelerometer, and temperature channels are stored in the logger. The magnetometer and accelerometer coefficients are unique to each instrument while temperature coefficients are specific to each manufacturing lot. The calibration coefficients are applied upon recovery when the binary data is converted to text data. Data is provided as text, and not corrected for the time drift. Time drift is provided as metadata in Table_TCM3EMSO_Azores 2016-2017.
Data management
- Real time data transmission: No
- Data storage in the Communication and storage unit (COSTOF2): No
- Data storage in the instrument: Full
Data
Alternative access to data
| File | Size | Format | Processing | Access | |
|---|---|---|---|---|---|
Current Data TCM3_3 | 20 Mo | TEXT | Raw data | ||
Temperature data TCM3_3 | 13 Mo | TEXT | Raw data | ||
Current Data TCM3_1 | 21 Mo | TEXT | Raw data | ||
Temperature data TCM3_1 | 13 Mo | TEXT | Raw data | ||
Sensor metadata | 1 Ko | CSV | |||
Sites | 54 octets | CSV | |||
Current Data TCM3_1 | 5 Mo | NetCDF | Raw data | ||
Current Data TCM3_3 | 5 Mo | NetCDF | Raw data |
How to cite
Sarrazin Jozee
Girard Fanny
Sarradin Pierre-Marie
