Classification of anomalous methane fields in the Sea of Okhotsk

• Main Authors: Shakirov,Renat B., Obzhirov,Anatoly I., Salyuk,Anatoly N., Biebow,Nicole, Terekhova,Valeriya E., Tsunogai,Urumu, Shoji,Hitoshi
• Format: Report
• Language: English
• Published: V.I. Il'ichev Pacific Oceanological Institute, Far Eastern Branch of the Russian Academy of Sciences/V.I. Il'ichev Pacific Oceanological Institute, Far Eastern Branch of the Russian Academy of Sciences/V.I. Il'ichev Pacific Oceanological Institute, Far Eastern Branch of the Russian Academy of Sciences/Alfred-Wegener-Institute for Polar and Marine Sciences/Kitami Institute of Technology/Hokkaido University/Kitami Institute of Technology 2005
• Subjects: anomalous and background methane fields; water mass; methane venting; hydrocarbon accumulations; methane hydrates; Okhotsk; Polar meteorology and glaciology
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2988; http://id.nii.ac.jp/1291/00002988/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2988&item_no=1&attribute_id=18&file_no=1

An original classification of anomalous methane fields according to the vertical structure of the water column in the Sea of Okhotsk is proposed. Basic types of anomalous methane fields are described: penetrating, near-bottom, deep, intermediate, subsurface, surface, and combined. Anomalous methane concentrations are greater than background values, sometimes by 1-3 orders(up to 30000nl/l above methane hydrates). Spatial and quantitative varieties of anomalous methane fields have genetic relations with different hydrocarbon sources. These varieties suggest a high permeability of active fault zones and geochemical activity in marginal areas, especially along the western Sea of Okhotsk.