DOI: 10.17882/112314
title: Time-series of ocean bottom currents from seafloor current meters at the Fåvne hydrothermal vent field, Arctic Mid-Ocean Ridge (AMOR)

description: This dataset contains ocean bottom current measurements acquired at the Fåvne hydrothermal vent site on the Mohn’s Ridge between July 2021 and July 2022 (GS21_TCM3-4; GS21_TCM3-5), and between July 2022 and June 2023 (GS22_RCM_508_20220715_1649_pp). The data were collected using TCM3 ocean bottom Tilt Current Meters (2021-2022) and Aanderaa seaguard single point current meter (2022-2023) deployed in close proximity to the Fåvne vent field.
[TCM3] The TCM3 ocean bottom Tilt Current Meter (Lowell Instruments LLC, North Falmouth, MA, USA) measures current velocity using the drag-tilt principle. The instrument is positively buoyant and anchored to the seafloor via a short flexible tether. Drag generated by moving water tilts the logger in the direction of flow. The internal accelerometer and magnetometer record the magnitude of tilt and the compass bearing, which are used to derive current speed and direction.
Further technical information and instrument specifications are available from the manufacturer (Lowell Instruments LLC) and in the Universal User Guide for the TCM3 Tilt Current Meter (https://lowellinstruments.com/tilt-current-meters/tcm-3-tilt-current-meter/).
[SEAGUARD] The SeaGuard Single Point Current Meter (Aanderaa Data Instruments AS, Bergen, Norway) measures current velocity using an acoustic Doppler principle (ZPulse technology). The instrument is typically mounted on a fixed frame or mooring and determines water current speed and direction within a single sampling volume located a short distance from the sensor head. Acoustic pulses are transmitted and the Doppler shift of the backscattered signal is used to calculate orthogonal velocity components, which are then resolved into current speed and direction; additional sensors (e.g., temperature, conductivity, pressure, oxygen) may be integrated depending on configuration.
Further technical information and instrument specifications are available from the manufacturer (Aanderaa Data Instruments AS) and in the SeaGuard Single Point Current Meter user documentation (https://www.aanderaa.com/).
Internal clocks were set to UTC prior to deployment. Post-recovery clock drift was not applied to the data files but is documented, when available, in the accompanying metadata file.
For each deployed instrument, the dataset includes text files with:
 - Current data
 - Temperature data
 - O2 concentration data
 - Turbidity data
 - Conductivity data
 
## Data organization and naming convention ##
The dataset is organized in a hierarchical structure with one master folder per deployed current meter. Each master folder contains all files associated with a single instrument deployment.
→ Master folder naming convention:
Each master folder follows the naming format: CruiseName_InstrumentType-InstrumentNumber
For example: GS21_TCM3-5 or GS22_RCM_508_20220715_1649_pp
where:
 - GS21 (/GS22) refers to the research cruise (G.O. Sars 2021), combining the vessel name and cruise year.
 - TCM3 (/RCM) refers to the instrument type and model identifier (Tilt Current Meter 3).
 - 5 (/508) refers to the specific instrument number or serial number.
 - 20220715 refers to the instrument launch date.
This naming convention ensures that each deployment is uniquely and clearly identified by cruise and instrument.
→ Folder structure within each master folder:
Each master folder contains the following subfolders and files:
raw This folder contains the original raw data files in their native formats (e.g., .csv, .txt, .xlsx). Files include current velocities and direction and temperature data. Current measurements have been corrected for magnetic declination. The magnetic declination value applied is documented within the folder and provided in an accompanying .png file. pp_mat This folder contains post-processed data in MATLAB (.mat) format. The data have been quality controlled and trimmed to include only the period during which the instrument was deployed at the seafloor. These files therefore represent the final dataset of scientific interest. figures This folder contains a set of standardized figures generated from the processed data. These figures display the time series and related diagnostics in multiple formats to facilitate quick inspection, quality assessment, and interpretation. photos When available, this folder contains photographs documenting the deployment and/or recovery of the instrument. Sensor metadata logsheet Each master folder also includes a Word document containing the sensor metadata logsheet. This document provides detailed information about the deployment and recovery, including dates, times, geographic coordinates, and relevant instrument configuration details.