E. I. Smolyaninova

Numerical modelling of regional neotectonic movements in the northern Black Sea

Abstract The paper examines the manifestation of tectonic processes related to the Neogene and recent subsidence of the Black Sea margin and uplift of the Crimea mountains as well as current seismicity in the southern Crimea. A 2-D finite-element model, based on a seismic line across the northern Black Sea and the Crimean mountains, that predicts the present-day tectonic velocity field, using the available neotectonic data as boundary conditions, has been developed. The model results indicate that the observed structure and tectonic motions cannot be explained by forces imposed on the external side, boundaries of the model only. Rather, movements consisting of upwelling beneath the Black Sea and subsidence under the Crimea, interpreted as the effects of mantle processes, are necessary to explain the observed topographic evolution of the area. Zones where the ratio of the calculated shear stress to calculated pressure is greatest correspond to the position of the Southern Coast fault that controls the seismicity of the northern Black Sea margin.

Constraints on the Neogene–Quaternary Geodynamics of the Southern Urals: Comparative Study of Neotectonic Data and Results of Strength and Strain Modeling Along the URSEIS Profile

Much geological and geomorphologic evidence indicates that the modern topography of the Southern Urals has been formed during the Neogene-Quaternary due to superposition of, (1) NW-SE compression and asymmetric uplift of the area as a whole, and (2) more vigorous transpressive uplift of the Central and Western Uralian blocks in the Late Pliocene-Quaternary. Strength modeling based on data on the deep structure, temperature and composition of the crust revealed that the Western and Central Uralian blocks are characterized by low total strength. Numerical strain modeling showed that vertical Neogene-Quaternary movements of the area can be a consequence of intraplate compression, maximum deformation being concentrated in weak blocks. The model predicts different deformational style in the upper and lower parts of inhomogeneous Uralide crust: the zone of maximum deformation at the top of the crust occurs in the Main Uralian fault zone while, in the lower crust, it is shifted 70 km to the west, where a vertical Moho offset (the so-called Makarovo fault) is located. Thus, this fault could have developed (or at least been sufficiently renewed) during Neogene-Quaternary.

The combination of methods for analyzing the amplitude and phase of satellite radar images for the estimation of displacements on landslide-affected slopes

The efficiency of combining methods for analyzing the amplitude and phase of radar images from the ENVISAT, ALOS, and TerraSAR-X satellites is shown based on a case study of a landslide in Baranovka Settlement, Greater Sochi. The offset tracking method in the amplitude field of the reflected radar signal allowed us to define the contour of the area where the landslide occurred in the night between January 23 and 24, 2012 and to estimate the displacements in different parts of the landslide body. The maximum displacement was 7.5 ± 1 m. The displacements prior to the landslide from January 22, 2007 until September 17, 2010, as obtained from the ALOS satellite by the persistent scatterer method, demonstrate seasonal autumn–winter accelerations. The time series of displacements from the ENVISAT satellite shows that from November 29, 2010 until July 27, 2011 the displacement rates in the line-of-sight direction vLOS were relatively small (21 mm/yr), but in the period from September 25, 2011 to December 24, 2011 the slide rate increased to 50 mm/yr. As obtained by the TerraSAR-X satellite, the slide rate vLOS after landsliding in the period from February 17, 2012 to March 10, 2012, reached 30 mm/month, but after June 6, 2012 it decelerated to 2–3 mm/month. Similar slide rates were also obtained for the same periods based on differential interferograms.

Geodynamic Models and Their Application in the Combined Interpretation of Geological and Geophysical Data (a Review)

The paper presents a review of investigations in the field of the theory and practice of the interpretation of geological and geophysical data with geodynamic models that were carried out mainly by researchers of the Institute of Physics of the Earth, Russian Academy of Sciences. Evolutionary models of platform structures, passive continental margins, rift zones, and orogens are examined. The review presents formulations of inverse problems and results of interpretation for various regions, including sedimentary basins of the East European Platform, Atlantic Ocean margins, the Caucasus, the South Urals, and others.