scholarly journals Disturbances in the primary stratigraphy of lake sediments on the Murmansk coast (Russia): their identification and relationship with catastrophic events

Baltica ◽  
2019 ◽  
Vol 32 (2) ◽  
pp. 156-169
Author(s):  
Svetlana Nikolaeva ◽  
Dmitriy Tolstobrov ◽  
Alena Tolstobrova

The results of lithological, diatom analysis and radiocarbon dating of bottom sediments of small coastal lake basins along the Murmansk coast of the Barents Sea (the Kola Region, Russia) are presented. Sedimentary successions of two lakes reveal the presence of distinctive deposits, very different from the sediment above and below. These deposits are represented by erosional unconformity beds, gyttja and sand mixed with plant macrofossils, and characterized by changes in diatom flora and sand in a matrix of organic material. The sediments were deposited due to different catastrophic events: paleo-tsunami and paleo-earthquakes. According to radiocarbon analysis data, a tsunami occurred between 10,400–8200 cal yr BP and a paleo-earthquake occurred between 8200–7200 cal yr BP. We discuss various causes and mechanisms for the formation of disturbances in lake sediments, including the Storrega tsunami and paleo-earthquakes, which during and after deglaciation were strong and frequent.

Vestnik MGTU ◽  
2020 ◽  
Vol 23 (2) ◽  
pp. 122-130
Author(s):  
E. A. Gorbacheva

Bioassay is used to study bottom sediment ecotoxicity in the central and eastern parts of the Barents Sea. The effect of sediment elutriates on the growth of microalgae Phaedactylum tricornutum Bohlin and survival of brine shrimp Artemia salina L. larvae has been studied. As shown by scientific evidence, low and moderately toxic bottom sediments are present in the Eastern Basin, West Novaya Zemlya and South Novaya Zemlya troughs along with non-toxic bottom sediments, which may be indicative of accumulation of pollutants in these areas of the Barents Sea. Toxic bottom sediments have not been found in the sea areas adjacent to them. Reduced survival rate in sediment elutriates of low and moderate toxicity has been shown predominantly by A. salina larvae. Only one sediment elutriate from the South Novaya Zemlya trough has had a slight toxic effect on Ph. tricornutum. The amount of fine-grained fraction (> 0.063 mm) in bottom sediments classified as low and moderately toxic is 24.8-66.8 % and do not differ from its amount found in bottom sediments classified as non-toxic - 27.8-76.9 %. The findings obtained are consistent with published chemical analysis data according to which the Eastern Basin, West Novaya Zemlya and South Novaya Zemlya troughs are included in the Barents Sea areas having highest amounts of a number of pollutants in bottom sediments.


2009 ◽  
Vol 87 (12) ◽  
pp. 1195-1209 ◽  
Author(s):  
E. Zeyl ◽  
J. Aars ◽  
D. Ehrich ◽  
L. Bachmann ◽  
Ø. Wiig

Parentage analysis data for 583 individuals genotyped at 27 microsatellite loci were used to study the mating system of polar bears ( Ursus maritimus Phipps, 1774) in the Barents Sea area. We discriminated statistically between full and half-siblings identified through only one common parent. We document for the first time multiple paternity in polar bears. We demonstrated for both sexes low fidelity to mating partners over time. We did not detect any significant difference between the age distribution of adult males at capture and the age distribution of males siring cubs. This might indicate that the male’s age and size are less indicative of the reproductive success than previously thought. This is further supported by a rather long mean litter interval of 3.9 years for males siring several litters. The mating system of polar bears in the Barents Sea appears to be promiscuous, usually with a single successful father siring full siblings within a year, but with consecutive litters of a mother being fathered by different males. We discuss how population density, landscape characteristics, and adult sex ratio might influence the mating system of polar bears. This is of particular importance for management decisions such as, e.g., implementing sex ratios in hunting quotas.


Author(s):  
Eleonora P. Radionova

The associations and ecological conditions of the existence of modern diatoms of the North-West (Pridneprovsky), Prikerchensky and Eastern regions of the subtidal zone of the Black Sea are considered. Based on the unity of the composition of the Present and Sarmatian-Meotian diatom flora, an attempt has been made to model some of the ecological c situation of the Late Miocene Euxinian basin.


Author(s):  
Ksenya V. Poleshchuk ◽  
Zinaida V. Pushina ◽  
Sergey R. Verkulich

The diatom analysis results of sediment samples from Dunderbukta area (Wedel Jarlsberg Land, West Svalbard) are presented in this paper. The diatom flora consists of four ecological groups, which ratio indicates three ecological zones. These zones show environmental changes of the area in early–middle Holocene that is demonstrating periods of regression and temperature trends.


Author(s):  
Valeriy G. Yakubenko ◽  
Anna L. Chultsova

Identification of water masses in areas with complex water dynamics is a complex task, which is usually solved by the method of expert assessments. In this paper, it is proposed to use a formal procedure based on the application of the method of optimal multiparametric analysis (OMP analysis). The data of field measurements obtained in the 68th cruise of the R/V “Academician Mstislav Keldysh” in the summer of 2017 in the Barents Sea on the distribution of temperature, salinity, oxygen, silicates, nitrogen, and phosphorus concentration are used as a data for research. A comparison of the results with data on the distribution of water masses in literature based on expert assessments (Oziel et al., 2017), allows us to conclude about their close structural similarity. Some differences are related to spatial and temporal shifts of measurements. This indicates the feasibility of using the OMP analysis technique in oceanological studies to obtain quantitative data on the spatial distribution of different water masses.


Author(s):  
V.N. Borodkin ◽  
◽  
A.R. Kurchikov ◽  
O.A. Smirnov ◽  
A.V. Lukashov ◽  
...  

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