In 2002 our IMAGES activity
has been concentrated mainly in the Russian marginal seas: Barents, Kara, Laptev
and Okhotsk Seas. Short sediment cores were main objects of this study. The
same time several "Marion Dufresne" long sediment cores in the Sea of Okhotsk
and in the eastern Pacific also have been undergone to study in Russia.
Several short sediment cores from Yermak Plateau (Fram Strait area) have been
studied as well.
Barents Sea:
This year we plan to finish several last papers devoted to the Late Weichselian-Holocene
paleoglaciology and paleoceanography of the Barents Sea and based on lithology,
grain-size, mineralogy, geochemistry, foraminiferal analysis, oxygen and carbon
isotopes of planktic and benthic foraminiferal tests, AMS C-14 data from 5 short
sediment cores obtained by R/V "Academik Sergey Vavilov" along the latitudinal
transect from Franz-Victoria Trough to South Novaya Zemlya Trough. That is a
joined work with our French colleagues from LSCE headed by J.-C. Duplessy. The
base of 6m long sediment core ASV987 from fjord Russkaya Gavan' (Novaya Zemlya)
has calendar age 800 yr, and composition of sediment reflects paleoclimatic
events related to the behavior of adjacent Shokalsky Glacier. This work is done
together with L.Polyak from Byrd Polar Centre (USA).
Kara Sea: Several short sediment cores along the Yenisei transect obtained by R/V "Academic Boris Petrov" now are in process of very intensive study (lithology, grain-size, optical and XRD mineralogy, large set of geochemical methods, benthic forams, diatoms, spores and pollen, oxygen and carbon isotopes, AMS C-14 dating). Main scientific problems are related to the extent of the Barents-Kara Sea ice sheet in the Late Weichselian, evolution of riverine discharge, sea level changes. This work is a part of SIRRO project - joint Russian-German program. In the frame of the project we collaborate mainly with German colleagues from AWI and GEOMAR headed by R.Stein and R.Spielhagen.
Laptev Sea: Last paleoceanographic studies of this basin are based on diatoms, spores and pollen, benthic foraminifers, ostracods, bivalves data with a number of AMS C-14 datings. Main scientific targets are the history of sea level changes coupled with an evolution of riverine discharge, and the history of Atlantic Waters advection from the Central Arctic in the basin. This work is done with German colleagues from GEOMAR headed by H.Bauch in the frame of joined Russian-German project "Geosystem of the Laptev Sea".
Sea of Okhotsk: A number of short sediment cores from all regions of the basin has been obtained in the frame of joined Russian-German project COMEX headed from the German side by N.Biebow (GEOMAR). At the present data on lithology, grain-size, mineralogy, geochemistry, forams, diatoms, radiolarians, palinology, isotope- and magnetostratigraphy, tephrochronology allowed to give a paleoceanographic reconstructions (history of Intermediate Waters, paleoproductivity, ice conditions, water mass exchange with the Pacific, etc.) up to 350 kyr. Two long "Marion Dufresne" sediment cores obtained in WEPAMA IMAGES VII cruise in 2001 (MD 012413 and 012415) in the central part of the basin with Russian participance will allow to continue the record up to 1.5-2.0 myr. The study of these cores is under progress in Moscow, Vladivostok and Kiel (GEOMAR). The German team is headed by R.Tiedemann
Eastern Pacific: This year Elena Ivanova participated in the IMAGES VIII MONA cruise of R/V "Marion Dufresne" along the California coast. It was planned that "the scientific goals include a high resolution reconstruction of the recent changes (400 000 yrs) of the Current of California and the associated upwelling system". Paleoclimatic and paleoceanographic studies will be done together with our French colleagues from CEREGE headed by L.Beaufort
Yermak Plateau: Several short sediment cores from Yermak Plateau obtained from the board of R/V "Polarstern" in 1997 have been studied by means of lithological, mineralogical and geochemical methods. The stratigraphic base for the study was created by specialists from GEOMAR and AWI (Germany). We managed to propose a number of new proxies for IRD, main surface circulation systems, Yenisei and Lena riverine input. On this base we reconstructed in qualitative manner the history of advection of Atlantic Waters in the Arctic, riverine discharge, sea ice/iceberg ratio, surface circulation pattern for the last 190 kyr.