Hydrochemical features of the Kara Sea aquatic area in summer 2015     

P. N. Makkaveev  A. A. Polukhin  A. V. Kostyleva  E. A. Protsenko  S. V. Stepanova  Sh. Kh. Yakubov 《Oceanology》2017,57(1):48-57

During cruise 65 of the R/V Akademik Mstislav Keldysh in the Kara Sea, three transects were executed: one eastwards from the Novaya Zemlya Archipelago and two in the St. Anna and Voronin troughs. It was noted that the continental runoff affected the entire surveyed aquatic area, even at the northern extremity of the Novaya Zemlya Archipelago. The transect along the St. Anna Trough showed the presence of a slope frontal zone overlaid at the surface by a desalinated layer. The Voronin Trough was characterized by sliding of slope waters. The hydrochemical parameters show that the surveys were carried out during a recession of biological activity of the waters and that the peak bloom was over by that time. The hydrochemical structure of waters conformed to early autumn conditions, but before the beginning of intense cooling of surface waters.  相似文献   

Hydrochemical structure of the waters in the eastern part of the Laptev Sea in autumn 2015     

S. V. Stepanova  A. A. Polukhin  A. V. Kostyleva 《Oceanology》2017,57(1):58-64

The study of the Laptev Sea was a part of a comprehensive program for investigating Arctic seas during the cruise 63 of the R/V Akademik Mstislav Keldysh. On a transect along 130° E (September 8–14, 2015) from the estuary area of the Lena River on the traverse of the city of Tiksi to the continental slope (over 700 km), water samples were taken to study the hydrochemical structure of waters and the influence of the Lena River flow. From the obtained data, it was found that the effect of fresh water on the sea surface layer was very high and can be traced to a great distance from the river delta. An unconservative distribution of some hydrochemical parameters in the mixing zone was recorded. The concentration of nutrients in the surface layer, and a high turbidity can serve as limiting factors in the development of the phytoplankton community.  相似文献   

A kinematic model of vertical geomagnetic field variation resulting from a steady convective flow     

Alexandra Marsenić 《地球物理与天体物理流体动力学》2014,108(2):191-212

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The Lemnos 8 January 2013 (M w = 5.7) earthquake: fault slip,aftershock properties and static stress transfer modeling in the north Aegean Sea     

Athanassios Ganas  Zafeiria Roumelioti  Vassilios Karastathis  Konstantinos Chousianitis  Alexandra Moshou  Evangelos Mouzakiotis 《Journal of Seismology》2014,18(3):433-455

We investigate mainshock slip distribution and aftershock activity of the 8 January 2013 M _w?=?5.7 Lemnos earthquake, north Aegean Sea. We analyse the seismic waveforms to better understand the spatio-temporal characteristics of earthquake rupture within the seismogenic layer of the crust. Peak slip values range from 50 to 64 cm and mean slip values range from 10 to 12 cm. The slip patches of the event extend over an area of dimensions 16?×?16 km². We also relocate aftershock catalog locations to image seismic fault dimensions and test earthquake transfer models. The relocated events allowed us to identify the active faults in this area of the north Aegean Sea by locating two, NE–SW linear patterns of aftershocks. The aftershock distribution of the mainshock event clearly reveals a NE–SW striking fault about 40 km offshore Lemnos Island that extends from 2 km up to a depth of 14 km. After the mainshock most of the seismic activity migrated to the east and to the north of the hypocenter due to (a) rupture directivity towards the NE and (b) Coulomb stress transfer. A stress inversion analysis based on 14 focal mechanisms of aftershocks showed that the maximum horizontal stress is compressional at N84°E. The static stress transfer analysis for all post-1943 major events in the North Aegean shows no evidence for triggering of the 2013 event. We suggest that the 2013 event occurred due to tectonic loading of the North Aegean crust.  相似文献   

Erratum to: The Lemnos 8 January 2013 (M w=5.7) earthquake: fault slip,aftershock properties and static stress transfer modeling in the north Aegean Sea     

Athanassios Ganas  Zafeiria Roumelioti  Vassilios Karastathis  Konstantinos Chousianitis  Alexandra Moshou  Evangelos Mouzakiotis 《Journal of Seismology》2015,19(1):273-273

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2.5 Ga gabbro-anorthosites in the Belomorian Province,Fennoscandian Shield: Petrology and tectonic setting     

A. V. Stepanova  V. S. Stepanov  A. N. Larionov  P. Ya. Azimov  S. V. Egorova  Yu. O. Larionova 《Petrology》2017,25(6):566-591

The Vorochistoozersky, Nizhnepopovsky, and Severo-Pezhostrovsky gabbro-anorthosite massifs have been studied in the central part of the Belomorian Province, Fennoscandian Shield. The similarity of geological setting and rock composition of these massifs suggests their affiliation to a single complex. The age of the gabbro-anorthosites was determined by U-Pb (SHRIMP II) zircon dating of gabbro-pegmatites from the Vorochistoozersky massif at 2505 ± 8 Ma. The studied massifs were overprinted by the high-pressure amphibolite facies metamorphism. Relicts of magmatic layering and primary magmatic assemblages preserved in the largest bodies. The massifs consist mainly of leucocratic gabbros but also contain rocks of the layered series varying in composition from olivinite to anorthosite. The presence of troctolites in the layered series indicates the stability of the olivine–plagioclase liquidus assemblage and, respectively, shallow depths of melt crystallization. Despite the composition differences between gabbro-anorthosites of the Belomorian and peridotite–gabbronorite intrusions Kola provinces, these simultaneously formed massifs presumably mark a single great igneous event. It also includes the gabbronorite dikes in the Vodlozero terrane of the Karelian province, the Mistassini swarm in the Superior province, and the Kaminak swarm in the Hearne Craton, Canadian Shield. The large igneous province of age ~2500 Ma reflects the oldest stage of within-plate magmatism after a consolidation of the Neoarchean crust of the Kenorland Supercontinent (Superia supercraton).  相似文献   

Influence of a position of the critical level inside a plane layer on the rise of magnetically and thermally driven instabilities     

Alexandra Marsenić  Sebastián Ševčík 《地球物理与天体物理流体动力学》2013,107(5):457-476

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Variations in fluid chemistry and membrane phospholipid fatty acid composition of the bacterial community in a cold storage groundwater system during clogging events     

Alexandra Vetter  Kai Mangelsdorf  Markus Wolfgramm  Kerstin Rauppach  Georg Schettler  Andrea Vieth-Hillebrand 《Applied Geochemistry》2012

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Factors affecting the distribution of potentially toxic elements in surface soils around an industrialized area of northwestern Greece   总被引：2，自引：0，他引：2  

Alexandra Petrotou  Konstantinos Skordas  Georgios Papastergios  Anestis Filippidis 《Environmental Earth Sciences》2012,65(3):823-833

In order to investigate the factors influencing the distribution of 32 potentially toxic elements in the Ptolemais–Kozani basin, northwestern Greece, 38 soil samples were collected and analyzed. Concentrations of Al, Ca, Fe, K, Mg, Mn, Na, P, Ti, Ba, Co, Cr, Cu, La, Li, Ni, Pb, Sc, Sr, V, Y, and Zn were determined by ICP-AES and concentrations of As, Bi, Cd, Cs, Mo, Rb, Sb, Th, Tl, and U by ICP-MS. Bivariate analysis, principal component analysis, and geostatistical analysis were employed to investigate the factors influencing the distribution of the elements determined in the study area. The results indicate that the distribution of the majority of elements determined, especially for Cr, Ni, and associated elements, is greatly influenced by the geology and geomorphology of the study area. Principal component analysis has yielded four factors that explain over 77% of the total variance in the data. These factors are as follows: lithophilic elements that are associated with Al silicates minerals of K (factor I: 29.4%), ultramafic rocks (factor II: 20.5%), elements that are coprecipitated with Fe and Mn oxides (factor III: 18.0%), and anthropogenic activities (factor IV: 9.3%). The anthropogenic activities that influence the distribution of several potentially toxic elements (i.e., Cd, Cu, Pb, Zn) are agricultural practices and the deposition of fly ash in the vicinity of the local power stations.  相似文献   

Fractal Dimension and Maximum Roughness Applied as Sculpture Descriptor for Tektites     

Ulrike Rantzsch  Alexandra Franz  Gert Kloess 《Mathematical Geosciences》2012,44(6):711-720

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