This dataset contains video and temperature data acquired with the MESOCOSME, deployed at the Montsegur edifice during the Momarsat 2021 cruise as part of the EMSO-Azores observatory from 9 to 11 June, 2021. Data consist in 5260 pictures. Pictures were taken every 2 seconds during 1 minute, every 15 minutes. The module was deployed autonomously at the base of the Montsegur edifice. Size of images: 3840 x 2160 pixels. The full dataset is 18.1 GO. Temperature data were acquired with 7 iButtons Thermocron along of a gradient of fluid influence every 5 minutes and include 1,124 measurement. Location :  - N 37°17.287 - W 32°16.538  - Depth : 1705 m