Abstract. The paper discusses the results of complex geological and geophysical studies of the deep structure of the seabed along the profiles “Magadan – Southern Kurils” (2-DV-M), “Shantar Islands – Northern Kurils” (1-OM) and “Cape Billings – Outer Continental Shelf Limits” (5-AR), carried out in 2006–2009 within the framework of the State program of expeditionary works on substantiation of national sovereignty over the continental shelf in the Sea of Okhotsk and East Siberian Sea. Federal State Unitary Scientific and Production Company Sevmorgeo was parent organization which managed the expeditionary works; the main executors were the staff of the V.I. Il’ichev Pacific Oceanological Institute of FEB RAS. A special role was assigned to gas-geochemical studies with the purpose to establish regional background and anomalous gas fields to assess prospects for oil, gas and gas hydrates. As a result of complex geological and geophysical expeditions led by A.A. Merezhko (Sevmorgeo) in the Sea of Okhotsk, it was established that the enclave outside the 200-mile zone in the central part of the water area does not differ in geological structure from the adjacent parts and is a natural continuation of the framing geological structures of the basement. The evidence obtained was sufficient to successfully justify the application to the UN. On March 11, 2014, after careful consideration of the application and draft recommendations, the enclave of international waters in the Sea of Okhotsk was legally assigned to the Russian Federation. Studies in the East Siberian Sea have provided a huge amount of data on lithology, geochemistry and gas potential of bottom sediments in this area.

For citation: Shakirov R.B., Maltseva E.V., Venikova A.L., Sokolova N.L., Gresov A.I. Complex geological and geophysical studies on substantiation of the outer limits of the Russian continental shelf in the Sea of Okhotsk and East Siberian Sea (2006–2009): Review. Geosistemy perehodnykh zon = Geosystems of Transition Zones, 2023, vol. 7, no. 3, pp. 264–275. (In Russ. & in Engl.).
https://doi.org/10.30730/gtrz.2023.7.3.264-275, http://journal.imgg.ru/web/full/f-e2023-3-3.pdf

1. Sakulina T.S., Kalenich A.P., Atakov A.I., Tihonova I.M., Krupnova N.A., Pyzhjanova T.M. 2011. Geological model of the Okhotsk Sea region according to basic profiles 1-OM and 2-DW-M. Razvedka i okhrana nedr = Prospect and protection of mineral resources, 10: 11–17. (In Russ.). EDN: OHAGYN

2. Sakulina T.S., Verba M.L., Kashubina T.V., Krupnova N.A., Tabyrtsa S.N., Ivanov G.I. 2011. Complex geological-geophysical researches on the 5-AP profile in the East-Siberian Sea. Razvedka i okhrana nedr = Prospect and protection of mineral resources, 10: 17–23. (In Russ.). EDN: OHAGYX

3. Obzhirov A.I. 1993. [ Gas-geochemical fields of the bottom layer of the seas and oceans ]. Moscow: Nauka, 139 p. (In Russ.).

4. Obzhirov A.I., Astakhova N.V., Lipkina M.I., Vereshchagina O.F., Mishukova G.I., Sorochinskaya A.V., Yugai I.G. 1999. Gas-geochemical zoning and mineral associations of the floor of the Sea of Okhotsk. Vladivostok: Dal'nauka, 184 p. (In Russ.).

5. Vereshchagina O.F., Korovitskaya E.V., Mishukova G.I. 2013. Methane in water columns and sediment of north western Sea of Japan. Deep Sea Research. P. II: Topical studies in Oceanography, 86-87: 25–33. https://doi.org/10.1016/j.dsr2.2012.08.017

6. Mishukova G.I., Shakirov R.B. 2017. Spatial variations of methane distribution in marine environment and its fluxes at the water–atmosphere interface in the western Sea of Okhotsk. Water Resources, 44: 662–672. https://doi.org/10.1134/S0097807817040133

7. Lelikov E.P., Malyarenko A.N. 1994. [ Granitoid magmatism of marginal seas of the Pacific Ocean ]. Vladivostok: Dal'nauka, 268 p. (In Russ.).

8. Vasiliev B.I., Sigova K.I., Obzhirov A.I., Yugov I.V. 2001. Geology and oil-gas resources of the marginal seas of the northwestern Pacific. Vladivostok: Dal'nauka, 303 p. (In Russ.).

9. Shakirov R.B. 2018. Gas-geochemical fields of the Eastern Asia marginal seas. Moscow: GEOS, 341 p. (In Russ.).

10. Kharakhinov V.V. 1998. [ Tectonics of the Sea of Okhotsk oil-gas province ]: [Doctor of Sciences (Geology and Mineralogy) dissertation]. Okha-na-Sakhaline: Sakhalin-NIPImorneft'. (In Russ.).

11. Geology and mineral resources of the Russian shelf areas: Atlas. 2004. Moscow: Publ. House Scientific world, 108 p.

12. Shakirov R.B., Sorochinskaya A.V., Obzhirov A.I. 2013. Gasgeochemical anomalies in the sediments of East-Siberian Sea. Vestnik KRAUNTs. Nauki o Zemle = Bull. of KRAESC. Earth Sciences, 1(21): 231–243. (In Russ.). EDN: RCCSOL

13. Gresov A.I., Obzhirov A.I., Yatsuk A.V., Mazurov A.K., Ruban A.S. 2017. Gas content of bottom sediments and geochemical indicators of oil and gas on the shelf of the East Siberian Sea. Russian Journal of Pacific Geology, 11: 308–314. https://doi.org/10.1134/S1819714017040030