Ocean Floor Observation and Bathymetry System (OFOBS) seafloor images of the Gakkel Ridge in the Arctic Ocean collected during RV POLARSTERN cruise PS138

• Main Authors: Boehringer, Lilian, Hoge, Ulrich, Tardeck, Frederic, Purser, Autun, Boetius, Antje
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA
• Subjects: Benthos; Central Arctic Ocean; Deep-sea ecology; Seafloor images; Arctic Ocean
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.971424

During the RV POLARSTERN cruise PS138 (2023-08-03 to 2023-09-30) to the Central Arctic Ocean the Ocean Floor Observation and Bathymetry System (OFOBS) was used to collect still and video images from various locations surveyed during the expedition. The OFOBS consisted of a towed underwater camera system equipped with a high-resolution photo-camera (iSiTEC, CANON EOS 5D Mark III) and a high-definition video-camera (iSiTEC, Sony FCB-H11) as well as an integrated sidescan sonar system. The cameras are mounted on a steel frame (140 L x 92 W x 135 H cm), together with two strobe lights (iSiTEC UW-Blitz 250, TTL driven), three laser pointers spaced with a distance of 50 cm used to estimate the size of seafloor strcutures, four LED lights, and a USBL positioning system (Posidonia) to track the position of the OFOBS during deployments, with additional positioning information provided by the integrated INS and DVL systems. An automatic seafloor image was taken every 20 seconds to obtain 'TIMER' stills distributed at regular distances along each of the survey profiles. Additional 'MANUAL' photos were triggered individually when interesting objects appeared in the live feed. In total, 16 OFOBS deployments were carried out. If no positions for the OFOBS were available, the ships position was used instead. Metadata in the form of iFDOs are available for each deployment containing a detailed description of the image collection and curation process.