IUGG 2003 Abstract

P02 Marginal and Semi-Enclosed Seas and their Exchange with the Open Ocean  Monday, June 30 PM Location: Site C, Room 25 Presiding Chair:M. Wakatsuchi

TIME [ 1430 ] [ P02/30P/C25-002 ]

DEEP WATER FORMATION IN THE DERUGIN BASIN OF THE SEA OF OKHOTSK

Anatoly N. SALYUK(V.I. Ilichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences)

Gisela WINCKLER(Lamont-Doherty Earth Observatory, Palisades, NY) Galina Y. PAVLOVA ( V.I. Ilichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences )

The Derugin Basin (DB) is the second big ″appendix″ in the Sea of Okhotsk after Kuril basin. It has maximal depth of about 1760 m and connected to Kuril basin by 2 channels with the sill depth of about 1300 m each. DB due to strong stratification supported by supplying of the Pacific waters in deep layers is not renewed directly from the surface. The formation and renewal of the deep waters (DW) in DB is discussed using new hydrochemical and isotopic data obtained during joint Russian-German project KOMEX (Kurile Okhotsk Marine Experiment) in 1998-2002. DW in DB show some features of stagnant waters such as very low dissolved oxygen (up to 14 uM/kg) and high silica (up to 267 uM/kg). But long renewal time of DW is found in contradiction with tritium data. Relatively small thickness of deep bottom layer observed on vertical profiles of potential temperature and salinity and relatively high spatial variability of some water properties such as oxygen also argue to relatively rapid exchange with the Pacific. Low dissolved oxygen in the DB DW not only indicate on poor ventilation, but also result of the fact that waters overflowing to the DB belong to the strong intermediate oxygen minimum layer (about 35 uM/kg) in the Sea of Okhotsk.