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Variations in the content of chlorin (a derivate of chlorophyll a) in 11 cores of bottom sediments from different parts of the Sea of Okhotsk are studied. The data show variations in paleoproductivity of this sea for the past 160000 years from the end of marine isotope stage (MIS) 6 until recently. A common pattern of the variation in paleoproductivity is established for the entire Sea of Okhotsk. During the interglacials (MIS 5e and 1), productivity increased, and in glacial periods, it decreased, probably due to the longer lasting marine ice cover throughout the year. The features of variations in productivity through time are recorded in the eastern part of the sea, which is more prone to the influence of inflowing Pacific waters. 相似文献
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A. S. Astakhov V. S. Markevich A. N. Kolesnik Rujian Wang V. V. Kononov M. S. Obrezkova A. A. Bosin 《Oceanology》2014,54(5):624-636
The study of the bottom sediments accumulated during the last 60–65 ka in the pockmark craters of the Chukchi Plateau in the Arctic Ocean showed that their composition and lithostratigraphy in general are similar to those of the background areas. A specific feature is the presence of sedimentary interlayers and horizons with signs of gravitational stirring, carbonate mineralization, and accumulation under H2S contamination conditions. The micropaleontological remains found in the pockmark sediments accumulated during the glacial periods are represented by redeposited species from Paleozoic, Mesozoic, and Cenozoic deposits, which are locally exposed in the pockmark walls. It was concluded that the pockmarks were formed under the influence of pulsed fluid flows. The present-day topography of the pockmarks was formed at the last stage of active defluidization (35?20 ka ago). 相似文献
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A. S. Astakhov V. A. Akulichev A. V. Dar’in I. A. Kalugin Yanguang Liu V. V. Babich A. A. Bosin E. G. Vologina V. V. Plotnikov 《Doklady Earth Sciences》2018,480(2):767-772
For the first time, the reconstruction of variations in the duration over several hundred years was conducted on the basis of models developed by comparing hydrometeorological observations and detailed scanning of the chemical composition of bottom sediments accumulated during the corresponding period. The gauge models for the reconstruction of air temperature and ice cover of the water area for three sites in the northern part of the Chukchi Sea have been developed. During the reconstruction, an insignificant increase in the duration of the ice-free period during the Little Ice Age was established, which does not coincide with the changes in the temperature regime that took place. It is concluded that the dynamics of the inflow of warm Pacific waters through the Bering Strait had the predominant influence on the ice regime of the Chukchi Sea. 相似文献
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M.I. Malakhov S.A. Gorbarenko G.Yu. Malakhova N. Harada Yu.P. Vasilenko A.A. Bosin E.L. Gol'dberg A.N. Derkachev 《Russian Geology and Geophysics》2009,50(11):973-982
Bottom sediments from the central zone of the Sea of Okhotsk were preliminarily dated. The petromagnetic parameters of two groups of samples formed at cold and warm climatic stages were studied. Warm oxygen isotopic stages and substages were characterized by the coexistence of pseudo-single-domain allogenic magnetite and predominant magnetite and greigite (pyrrhotite) grains subject to biologic control. At cold stages, sediments containing a mixture of pseudo-single-domain and multidomain terrigenous magnetite particles accumulated. The petromagnetic curves agree with the normalized standard oxygen isotopic curve over the last 350 kyr of the column section. 相似文献
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Using the authors’ data obtained during expeditions to the Sea of Okhotsk during the last decade, the primary phytoplankton
production and the distribution of organic carbon and chlorophyll a degradation products (chlorin) in the bottom sediments were studied. Using the authors’ and published data, the spatial distribution
of the production and paleoproduction indicators was plotted. The ratios of the chlorin and Corg content in the sediments was considered, and the correlation between these parameters was revealed. It was shown that the
average annual primary production of phytoplankton and the paleoproduction indices were maximum in the coastal and upwelling
zones and decreased towards the sea’s center. A quantitative correlation was found between the distribution of the present
primary production in the photic layer and that of the rates of the accumulation of organic matter buried within the surface
sediments. As a result, it was shown that the content of chlorin and Corg in the marine bottom sediments may be used to reconstruct the paleoproduction variability of the past. 相似文献
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Kolesnik A. N. Bosin A. A. Kolesnik O. N. Yanchenko E. A. Vasilenko Yu. P. 《Doklady Earth Sciences》2020,495(1):845-849
Doklady Earth Sciences - A new method of quantitative determination of color using an original photodevice is presented for marine sediments, which are a specific geological object. The advantages... 相似文献
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Sergey Alexandrovich Gorbarenko Evgenia L’vovich Goldberg Michaele Kashgarian Tat’yana Alekseevna Velivetskaya Sergey Petrovich Zakharkov Vladimir Stepanovich Pechnikov Alexandr Anatol’evich Bosin Olga Yur’evna Psheneva Elena Diamilevna Ivanova 《Journal of Oceanography》2007,63(4):609-623
The paper presents the records of several paleoproductivity proxies (PP) (biogenic opal and Ba (Si_bio, Ba_bio), organic carbon
(C_org) and carbonate Ca_carb, chlorin and benthic foraminifera abundance (BFA)) in sediments of the Okhotsk Sea for the last
80 kyr with a resolution of ∼100–300 years. The sediment age model was based on the AMS 14C data, records of benthic foraminifera δ18O, paleointensity of the Earth’s geomagnetic field and magnetic susceptibility. PP values demonstrate series of severe prolonged
productivity drops in the Okhotsk Sea followed by a sharp increase during the last glaciation. On the basis of quantitative
estimations of the paleoproductivity in the Okhotsk Sea during the cold MIS 2 and warm Holocene (Gorbarenko and Goldberg,
2005), it is suggested that the millennium scale relationship in productivity-climate changes of this basin was similar: an
increase in the sea’s productivity was related with regional climate warming and vice-versa. The PP records of productivity/climate
oscillations in the Okhotsk Sea during MIS 2–4 occurred contemporaneously with the North Atlantic cold Heinrich events (HE)
and Greenland Dansgaard-Oyeshger interstadial (DOI). Observed successions of prolonged climate cooling events followed by
rapid, abrupt warming are similar to climate and environmental oscillations in the N. Atlantic and Greenland, that confirms
the millennium-scale climate changes synchronicities in the Northern Hemisphere including the far NW Pacific, the hydrology
and climate conditions of which are close to those of the Okhotsk Sea. Synchronism of the N. Hemisphere severe cooling (including
the Okhotsk Sea) with the Antarctic warming suggests that mechanisms of the “seesaw” effect (Blunier and Brook, 2001) in the
low latitude heat redistribution between high latitudes of both hemispheres were more complicated than direct NADW formation
forcing and encompasses the global atmospheric reorganization. Within the PP used a closer connection in the Okhotsk Sea millennium
oscillations was observed for the C_org, BFA and chlorin; Ba_bio increases more closely to DOI. Si_bio variability does not
show any evident correlation with productivity changes. 相似文献
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E. G. Vologina M. Sturm I. A. Kalugin A. V. Darin A. S. Astakhov G. P. Chernyaeva A. N. Kolesnik A. A. Bosin 《Doklady Earth Sciences》2016,469(2):841-845
Integrated studies were performed on bottom sediments collected in the Chukchi Sea in the northern part of the Gerald Canyon 150 km northeast from Wrangel Island. The recent sedimentation rate amounted to 0.9 mm/year by 210Pb at the sampling site. The concentrations of biogenic components (SiO2bio, Сorg, Ntot, and Br) were minimum at the lower part of the core, where an increase of Thalassiosira antarctica antarctica, probably results from low biological productivity during the Maunder Minimum. The increased concentrations of biogenic components, as well as the decreased values of magnetic susceptibility and X-ray density, in the upper part of the core (1–2 cm) correspond to the last decade of recent of global warming. 相似文献