This dataset contains temperature data acquired between July 2017 and August 2018 with an array of 27 autonomous temperature probes installed in smoker orifices, cracks or patches of diffuse hydrothermal venting.

We used 6 types of probes (HTW, HTWN, HTNKE, LTW, LTNKE and LTiButton). Probes locations, acquisition parameters and clock drift values (UTC-timeprobe) are listed in the metadata file "Sensor Metadata"

Operating parameters : Temperatures are recorded at a frequency of: 1 meas. per 1 to 15 minutes (HTW, HTWN, HTNKE probes and LTW probes); 1s to 1 minute (LTNKE probes); and 2 hours (LTiButton).

Sensor metadata : High-temperature WHOI probes (HTW) contain of 2 J-type thermistors in their rod tip connected to 2 temperature data-loggers (named A & B), 2 data recordings are thus available for each probe. HTW probes record temperatures up to 415°C with an accuracy of ± 1.1°C, a resolution of 0.25°C at 375°C and a clock drift of about 1min per month.

New high-temperature WHOI probes (HTWN) contain 1 temperature data-logger and 1 attitude logger to measure absolute orientation (tilt) and acceleration. The thermocouple in their rod tip can be J or T-Type. We mostly use J-Type thermocouples. These record temperatures up to 450°C, with an accuracy of ± 0.6°C, a resolution of 0,03°C and a clock drift of about 1min/year.

High-temperature NKE probes (HTNKE) record temperatures up to 450°C, with an accuracy of ±0.5°C, a resolution of 0.1°C and a clock drift of about 1min/month.

Low-temperature WHOI probes (LTW) record temperatures up to 125°C, with an accuracy of ±0.22°C, a resolution of 0.025°C and a clock drift of about 1min per month.

Low-temperature NKE probes (LTNKE) record temperatures up to 100°C, with an accuracy of ±0.5°C, a resolution of 0.12°C at 60°C and a clock drift of about 1min/month.

Low-temperature iButton probes (LTiButton) record temperatures up to 85°C, with an accuracy of ±0.5°C, a resolution of ±0.5°C and a clock drift of about 1min/month.

All probes are calibrated in time before deployment, probe time adjusted to UTC time. Temperature of probes is checked after recovery and before deployment. Clock drift after recovery is not implemented in data.

Test and calibration : All probes are calibrated in time before deployment, probe time adjusted to UTC time. Temperature readings of WHOI probes are checked at IPGP after recovery and before deployment using an oven in the laboratory. NKE probes are sent back to factory every 3-4 years for battery change and calibration. Clock drift after recovery is not implemented in data but listed in the metadata file "Sensor Metadata"

Data management

• Real time data transmission: No
• Data storage in the Communication and storage unit (COSTOF2): No
• Data storage in the instrument: Full