Expedition to the zone of oil and gas discharges and gas-hydrate accumulations, 9 to 15 March 2022

The aim of expedition was to clarify the depths of the water column and sub-bottom occurrence of gas-hydrate accumulations near seeps Melkiy and Zelensip (Central Baikal) as well as to measure near-bottom and bottom temperatures in the water and sediments of the lake.

In the course of the fieldwork, scientific research was continued at the sites of gas-hydrate accumulations at the boundary of their stability near the Melkiy seep at depths of 371 to 380 m. The depths of the sites of gas-hydrate accumulations discovered in the autumn of 2021 was clarified by hydrophysical methods and direct measurement of the marked cable. The temperatures of bottom sediments were measured in situ using autonomous THP sensors to depths of 2 m below the bottom for the monitoring that began in 2020 in this area from the ice and from the board of the research vessel. Similar work was carried out at the site of the Zelensip seep (418 to 425 m). The site of oil discharge was searched at the lake bottom opposite the estuary of the Bolshaya Zelenovskaya River (240 to 250 m) where oil floats to the surface of Lake Baikal in the form of large balls.