Geoarchaeological evidence on a Late Bronze Age earthquake,Ohrid Basin (North Macedonia)     

J. Hošek  M. Verčík  P. Pokorný  J. Beneš  V. Komárková  T. Radoměřský  N. Atanasoska  V. Todoroska  P. Ardjanliev 《第四纪科学杂志》2021,36(6):1003-1012

Geoarchaeological investigations on the northeastern shore of Lake Ohrid revealed 3.5 m thick deepwater lacustrine sediments overlying terrestrial vegetation macrofossils, worked wood and abundant potsherds dated to the Late Bronze Age (LBA). Distinct contact of deepwater sediment with the sub-aerial weathered limestone bedrock point to a sudden increase in lake level. According to radiocarbon data, catastrophic flooding occurred shortly after 1214 yr bc. Because the area is located in a highly active seismic zone, we propose that this event was caused by tectonically induced, metre-scale coseismic subsidence related to faults bordering the Ohrid alluvial plain. Moreover, this event coincides well with a dramatic switch in the habitation and settlement strategy in the region. More important, however, is the finding that the age of the proposed massive tectonic event and change in habitation lies within the interval of the proposed ‘earthquake storm’ in the eastern Mediterranean dated to 1225–1175 bc. As the Ohrid-Korça zone belongs to the same tectonic province, a relationship between the abovementioned earthquakes and the proposed event can be expected. This research therefore might provide the first direct evidence of a large-scale earthquake event linkable to the LBA collapse of Europe's first urban civilisation in the Aegean.  相似文献   

Very quiet intervals of geomagnetic activity and the solar wind structure     

Jaroslava Hruska  Antonin Hruska 《Pure and Applied Geophysics》1989,131(3):343-355

Extended periods of very low geomagnetic activity as described by very quiet intervals (VQI's) occur only at those times when the solar wind velocityV has a generally decreasing trend, i.e., they mainly occur either after the velocity peak of a high speed solar stream has passed the Earth, or at times when the Earth is immersed in a low speed solar plasma provided that the daily mean value ofdV/dt is negative. The VQI's most frequently start whendV/dt<0 anddB _Z/dt>0 (B _Z is the geocentric solar magnetrospheric-GSMZ-component of the IMF) and end most likely whendV/dt>0 anddB _Z/dt<0. The temporal trends of the solar wind (SW) velocity affect the variation of thea _p index only when the level of geomagnetic activity is generally low.It is suggested that a gradual expansion or contraction of the magnetosphere, associated with a slow variation of the SW pressure, plays a role in the modification of the reconnection-driven magnetohydrodynamic (MHD) fluctuations in the magnetosphere.  相似文献   

Deep structure of the lithosphere beneath the territory of Bulgaria     

Vladislav Babuška  Jaroslava Plomerová  Edelvays Spasov  Reviewer J. Janský 《Studia Geophysica et Geodaetica》1987,31(3):266-283

Summary Teleseismic P residuals calculated for waves arriving from various azimuths and angles of incidence, and a 3-D inversion of the residuals provided the basis for characterizing the uppermost mantle structure beneath Bulgaria. The Moesian Platform and the Rhodopean Massif are two different blocks characterized by a lithosphere thickness of about 130–140 km with a zone of lithosphere thinning along their contact. Both units have opposite patterns of the directional dependence of relatively high and low P velocities. This directional dependence is interpreted by dipping anisotropic structures in the subcrustal lithosphere, which probably represent remnants of paleosubductions of an old oceanic lithosphere.

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Latitude variation of the LHR frequency in the outer ionosphere as an indicator of the degree of magnetospheric perturbance     

Jaroslava Bošková  František Jiřiček  Pavel Tříska  Reviewer S. Fischer 《Studia Geophysica et Geodaetica》1983,27(3):298-304

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Weather categorization in climate change research: Preliminary results     

Ivana Nemešová  Nina Klimperová  Radan Huth  Jaroslava Kalvová 《Studia Geophysica et Geodaetica》1992,36(4):370-375

Summary The results of an objective weather categorization are presented. The 9 meteorological variables recorded daily during winter seasons of 1961–66 at Prague-Clementinum represent the input dataset. The principal component analysis and a few clustering procedures have been evaluated. 5 component solution and the average linkage clustering method were found optimal. The winter days have been grouped, according to their meteorological character, into 14 clusters. The warm categories represent 20% of the time and the cold categories less than 15% of the days. The mean maps of 1000 hPa and 500 hPa are shown for a few selected categories. Clustering techniques applied to long-time instrumental series can provide a better basis for attempting to detect temperature changes which have taken place over a long time span.  相似文献   

Ein Zusammenhang der NächtlichenE-Schicht mit der Geomagnetischen Aktivität     

Jaroslava Hájková  Jiří Mrázek 《Studia Geophysica et Geodaetica》1959,3(2):195-198

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Systematisch-ökologische Bemerkungen zu den Arten des FormenkreisesPhormidium autumnale     

Dr. Edith Kann  Dr. Jiří Komárek 《Aquatic Sciences - Research Across Boundaries》1970,32(2):495-518

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Köppen Climate Types in Observed and Simulated Climates     

Kalvová  Jaroslava  Halenka  Tomáš  Bezpalcová  Klára  Nemešová  Ivana 《Studia Geophysica et Geodaetica》2003,47(1):185-202

The Köppen climate classification was applied to the observed gridded climatological sets and the outputs of four general circulation models (GCMs) over the continents of the Earth. All data had been acquired via the Data Distribution Centre established by the Intergovernmental Panel on Climate Change. The ability of the GCMs to simulate the Köppen climate zones identified in the real data was explored and possible future (global warming) changes in the climate types' distribution for each GCM were assessed. Differences in the area distributions derived from the GCMs' recent climate simulations give evidence about uncertainties generally involved in climate models. As to the global warming simulations, all GCM projections of warming climate (horizon 2050) show that the zones representing tropical rain climates and dry climates become larger, and the zones identified with boreal forest and snow climates together with the polar climates are smaller.  相似文献   

Comparison of regression relations between the monthly sums of sunshine and global radiation at selected stations of the CSSR     

Jan Bednář  Jaroslava Kalvová  Reviewer F. Smolen 《Studia Geophysica et Geodaetica》1981,25(2):192-203

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On characteristic frequencies of a five-component model of magnetospheric plasma     

Jaroslava Bošková  Reviewer K. Dobeš 《Studia Geophysica et Geodaetica》1978,22(2):160-164

Summary The author gives more general relations derived for characteristic frequencies of a more complex plasma model. One may assume that expressions derived herein, represent a more appropriate approximation of reality, especially in regions of ionospheric and magnetospheric plasma with a higher concentration of heavy ions.  相似文献