N.A. Florensov and N.A. Logatchev pioneered development of fundamental concepts of the structure and evolution of the Baikal system of rift basins. At the turn to the 21st century, in view of the wide availability of scientific research data on the Cenozoic continental rift zones located in Eurasia, Africa and North America, and taking into account the application of new research methods and options to process and analyze huge amounts of geological and geophysical data, a priority was comprehensive modeling of rifting from its origin to the current period of time. This scientific challenge was addressed by the research team under the leadership of N.A. Logachev.

This paper presents research results of the study which aim is to reveal and quantitatively describe fractal properties of the European-Mediterranean seismotectonic model applied for seismic hazard assessment of the region under study.

Several seismotectonic provinces are defined, and their nonlinear properties are calculated using both linear elements (boundaries of seismogenic units) and surface areas of the seismogenic units.

The research is conducted on the basis of only formal relationships, not with data on real fault structures or other seismogenic elements, as the relationships have been accepted for seismic hazard calculations by the team of SESAME Project (Project Leader M. Jimenec) and published by Jimenec et al. [2001].

Special attention is paid to the Balkan seismotectonic model in order to develop a common seismotectonic model which uses data from the seismic hazard map for a period of 475 years (according the EUROCODE8), that was published in Muco et al. [2008].

All the calculations considered only the seismogenic units located in the earth crust, but not deeper seismogenic layers.

It is concluded that most of the seismogenic provinces are similar in their fractal properties, which varied in a narrow range, except for the Adriatic one. The formal approach does not permit to explain these peculiarities.

Earthquake concentration areas in the changeable stress-strain medium are considered. In strong earthquake centres, rupturing occurs within the limits of the arbitrarily-set boundary between deformations of positive and negative values in the field of latitudinal, meridional and vertical components of seismotectonic deformation (Fig. 1–12).

In the Earth's lithosphere, wavy alternation of positive and negative heterochronous structures is revealed; such structures are variable in ranks and separated by vergence zones of fractures and folds. In the vertical profile of the lithosphere, alternating are layers characterized by relatively plastic or fragile rheological properties and distinguished by different states of stress. During the Earth’s evolution, epochs of compression and extension are cyclically repeated, including planetary-scale phenomena which are manifested by fluctuating changes of the planet’s volume. Migration of geological and geophysical (geodynamic) processes takes place at the Earth's surface and in its interior. The concept of the wave structure and evolution of the Earth's lithosphere provides explanations to the abovementioned regularities. Wavy nature of tectonic structures of the lithosphere, the cyclic recurrence of migration and geological processes in space and time can be described in terms of the multiple-order wave geodynamics of the Earth's lithosphere that refers to periodical variations of the state of stress. Effects of structure-forming tectonic forces are determined by «interference» of tangential and radial stresses of the Earth. The tangential stresses, which occur primarily due to the rotational regime of the planet, cause transformations of the Earth’s shape, redistributions of its substance in depths, the westward drift of the rock mass in its upper levels, and changes of structural deformation plans. The radial stresses, which are largely impacted by gravity, determine the gravitational differentiation of the substance, vertical flattening and sub-horizontal flow of the rock masses, and associated fold-rupture deformation. Under the uniform momentum geodynamic concept proposed by [Vikulin, Tveritinova, 2004, 2005, 2007, 2008], it is possible to provide consistent descriptions of seismic and volcanic, tectonic and geological processes, i.e. migration waves of seismic and volcanic activity, plate movements, vortex and other structures.

In our study, an earthquake focus is viewed as a 3D zone of the Earth’s crust, wherein the discharge of mechanical loading is accompanied by recordable destruction and qualitative transformation of the geological medium. The purpose of the present publication is to make an attempt to reveal a direct relationship between seismicity and deformation-metamorphic processes which took place in the Earth’s crust. Traditional and alternative interpretations of geomechanics of seismic-foci situations are discussed. The problems of geodynamics and geostatics of the seismic-foci systems and their concentrations, as well as anthropogenic models and mechanisms of focus medium structuring are reviewed. The relationship between seismicity and mechanisms of «regional shearing» or formation of crustal deformation-metamorphic structures of lineament type is outlined in the example of the Chuya seismic system of earthquakes which occurred in 2003 and afterwards in the Altai region.

The article reviews research problems and perspectives of studying the secondary seismogenic deformations of vibrational type (termed «seismites») that are revealed in soft sediments in the territory of the Southern East Siberia. Proposed are ways and principles based on which criteria can be developed for definition of similar structures in view of wide propagation of cryogenic processes. Studies to reveal seismites in cross-sections of the Selenga river delta, the Tunka basin and the southern part of the Siberian platform have been conducted; some of the research results are presented in the article.

The Priolkhonie is a tectonic block located in the central part of the Baikalsky Ridge; it was shifted in the Cenozoic, yet remains above the water level of Lake Baikal. In view of its unique positioning and abundant rock outcropped sites, especially at shorelines, we conducted studies of internal structures of the main fault zones and reconstructed the states of stresses associated with formation of such zones.

The studies were conducted along the profile which goes across the Priolkhonie, from the Primorsky Ridge near the Sarma River to the Tutai Bay in the Olkhonskie Vorota Strait (Fig. 1). Detailed cross-sections are constructed to characterize the internal structures of the fault zones striking of the NE-strike, that are located in highly outcropped sites at the shorelines of the Mukhor, Kurkut and other bays.

The state of stresses in the fault zones and their vicinities are studied (Fig. 2, 3) by the structural paragenesis analysis of the second-rank ruptures and fracturing nearby the fault planes [Seminsky, Burzunova, 2007]. As possible, the obtained results are checked by the kinematic method which provides for reconstruction of the main axes of normal stresses [Parfenov, 1984].

Most of the fault zones are complicated in structure (Fig. 4–7): the fault is typically represented by alternating areas, wherein tectonites of the main fault are developed, and areas of high fracturing at the periphery of the fault zone. With this approach, the fault zone’s boundaries are defined by quantitative indicators of tectonic fracturing, being abundantly manifested in the rocks.

Our solutions give evidence that extension (Fig. 8) and shear fractures are abundant in the area under study, while fractures caused by compression are revealed quite rarely. The faults of the above mentioned morpho-genetic types have been revealed in the studied outcrops in the following ratio: 55 %, 27 %, 10 %, and 8 %. Our study gives grounds to conclude that the state of stresses of the upper crust in this territory developed from compression, via shear, to extension. It is also evidenced that strike-slip faults with the left-lateral component and normal faults developed in the Cenozoic.

The information on the «Problems of seismicity and recent geodynamics of the Far East and Eastern Siberia» Symposium is presented. It was held on June 1–4, 2010 at the Yu.A. Kosygin Institute of tectonics and teophysics, Far Eastern branch, Russian academy of sciences, Khabarovsk. The scope of plenary meetings, sessions and round-table discussions conducted during the Symposium is presented with a brief review of the most interesting scientific reports.

The information on the «Cenozoic Continental Rifting» Symposium dedicated to the memory of Academician N.A. Logachev is presented. It was held on June 7–11, 2010 at the Institute of the Earth’s Crust, Irkutsk. The scope of conference is presented.