Sediment echosounder raw data (Atlas Parasound P70 echosounder entire dataset) of RV MARIA S. MERIAN during cruise MSM120

During cruise MSM120 (August 17 – September 17, 2023), sub-bottom profiles were acquired in the Labrador Sea and Hudson Bay using the hull-mounted PARASOUND DS3 (PS70) parametric echosounder on RV MARIA S. MERIAN. The PARASOUND system emits high-frequency primary signals (18–24 kHz) and secondary low-frequency signals (0.5–7 kHz) via a narrow 4.5° beam, enabling high-resolution imaging of small-scale seafloor structures and sediment layers down to ~150 m penetration in soft sediments. Data were recorded in single pulse, quasi-equidistant, and transmission-on-request ping modes depending on water depth and operational constraints. Beamforming corrected for vessel motion, and acquisition parameters (sample rate, recording window, and source level) were adapted for shallow and deep-water areas. Raw data including signal amplitude, phase, and system parameters were stored in Atlas Sound Data (ASD) format and exported in SEG-Y and PS3 formats. The dataset provides detailed sub-bottom information for sedimentological and geohazard studies, supporting high-resolution mapping of the Labrador Shelf, Labrador Sea, and Hudson Bay seafloor.