Abstract: Some characteristics of the seismic regime of the Baikal rift zone for the analogue (1960–2000) and digital (2001–2006) registration modes are considered. It was ascertained that the general number of seismic events recorded by digital equipment increased by two times in comparison with the analogue observation period and the catalog completeness level was lowered to KP = 7.0 as well. The focal mechanisms of 110 earth-quakes with KP ≥ 8.0 were examined. The overwhelming majority of them during 2001–2006 were due to normal faulting and normal faulting with strike-slip components. Special attention was given to study of the strong events (KP ≥ 13.5 and MPSP ≥ 4.7), whose focal solutions reveal the regional stress field.

Abstract: Development and application of broadband seismic sensors, namely velocimeters of electrochemical type (chemotrons), are considered. The principle of operation and design of modern electrochemical (molecular-electronic) converters of seismic signals for linear and rotary motions are described. The data on metrological certification and prolonged trials of these seismic sensors on test benches are presented. Their advantages as compared to stationary broadband seismic sensors of electrodynamic type lie in impact immunity, high power supply efficiency, operability at large inclinations and in a wide temperature range. Comparative analysis of records of the Sichuan Earthquake (China, May 12, 2008) obtained in Moscow on a test bench at the Institute of Physics of the Earth of the Russian Academy of Sciences with help of an electrodynamic seismic sensor and on a test bench at the Design Bureau of Oceanological Equipment of the Russian Academy of Sciences with the help of an electrochemical sensor is presented in conclusion.

Abstract: The catalog of earthquakes that happened in Greece over the period of 1964 to 2008 was used for the analysis of their diurnal periodicity in this region. The quality of the catalog was examined with the defining of the representativeness levels of earthquakes in different selections. The earthquakes, including relatively strong events with the magnitude M ≥ 4.0, demonstrate diurnal periodicity with seasonal differences in their course reflected in their higher summer seismicity as compared with the winter one.

Abstract: Development of powerful generators of the alternating current working from an industrial network in a wide spectrum of ULF-ELF frequencies range (0.1–200 Hz) is a prospective direction of researches in the field of creation of effective means for electromagnetic monitoring of earthquakes focuses. The present article is devoted to description of the successive stage of works on creation of generator “Energy-2” with capacity up to 200 kW, operating from an industrial three-phase network of 380 V voltage and frequency of 50 Hz. The schematic concept, element base and parameters of the output high-voltage power inverter of up to 1100 V voltage and 400 A current are described. In the course of designing the design documentation was developed, the drawings and circuits were made, the accessories were got, bearing structures were manufactured in skilled-industrial workshops, as well as heat-protective units radiators and ventilators, settlement-theoretical works and computer modeling was carried out. The main basic element of novelty was development of the system providing the programmed (arbitrary) form of current signals in a wide spectrum of frequencies from 0.1 to 200 Hz at power consumption of up to 200 kW. The created unit of the high-voltage inverter is designed for installation in the car body of motor vehicle ZIL-131 in the set with other units of multipurpose generator “Enerrgy-2” with the capacity of up to 200 kW. The important feature of the inverter is its multifunctionality. It permits to use the generating complex Energy-2 for monitoring of earthquake focuses in one of three modes frequency sounding, formation of the field or induced polarization. Selection of on of three monitoring modes depends on the characteristics of seismically active environment and purposes of the Earth crust sounding.

Abstract: The paper deals with issues related to the testing of the ESI-2007 scale by using as an example the real seismic event that occurred on August 27, 2008 in South Baikal. The main objective of the paper is to carry out a comparative assessment of the earthquake’s intensity based on traditional macroseismic scales and environmental seismic intensity (ESI-2007) scales. The results of the macroseismic survey served as the initial data. Analysis has been made on the ESI-2007 scale in conformity with the requirements for seismic scales. Particular emphasis has been placed on the type (or rank) of the ESI-2007 scale. Such an investigation is one of the first cases of the application of a new scale by the example of a regional seismic event.

Abstract: In this work, the macroseismic effects of the Kultuk earthquake (MW = 6.3), which took place on August 27, 2008 in the southwestern closure of the Baikal Lake, are under consideration. The intensity of shocks in inhabited localities located in the epicentral zone reached 7–8 points on the MSK-64 scale. The earthquake was named after the local settlement of Kultuk, which was the mostly damaged area by the earthquake. The considered seismic event caused significant material damage (about 250 million rubles according to preliminary estimates). In inhabited localities of Southern Pribaikalie thousands of cases of damaged ovens and chimneys were registered. Some buildings were highly damaged and, accordingly, they are unfit for further use. The earthquake was the cause of numerous rockslides, rockfalls, and landslides on steep natural and artificial slopes. A macroseismic survey allowed us to establish the asymmetrical distribution of the intensity of shocks relative to the epicenter.

Abstract: A search for technogenic effects in the time series of earthquakes in Greece is carried out. The ine- quality of intra-week distributions of earthquakes including the events of M ≥ 3.7 is shown. Sharp changes in the pattern of Rayleigh-Schuster’s hodograph for the diurnal periodicity of earthquakes were revealed. They are located in the time vicinity of the moments of the equinox. The result supports the idea of the natural gen- esis of the diurnal periodicity of earthquakes and the important role of the Sun.

Abstract: In this work the data on earthquakes in the Pribaikalie over the pre-instrumental observation period are given. The methods of determination of local and remote earthquakes with limited information of macroseismic effects are considered. A lists of strong (M ≥ 5) earthquakes in the southern Pribaikalie, as well as a list all earthquakes in the Southeastern Transbaikalian and the South of the Siberian platform, is given.

Abstract: Intensity of the Muya, 1957 earthquake is assessed in localities based on macroseismic data and in epicentral area based on effects in natural environment; it is analyzed how these assessments correspond to each other and to instrumental location of epicenter, hypocentral depth, and magnitude; it is evaluated, how seismodislocations of the Muya earthquake could serve as control of palaeoseismostructure parameters in this region. Spatial distribution of macroseismic effect confirms relatively deep source (20–22 km). Deep source agrees with anomalously short surface rupture length (not more than 25 km); only a part of the source exposed on the surface. Comparison with length of palaeoseismostructures shows that it is a regional feature. Epicentral intensity based on surface ruptures is assed X degrees in ESI2007 scale. Ignoring geological effects will underestimate epicentral intensity up to two degrees. Source mechanism with three sub-sources is in agreement with segmentation of surface ruptures. Sub-sources are of strike-slip type with small normal component; essential normal slip at surface is probably not representative for the source and is due to accommodation of strike-slip movement along with a system of sub-parallel en echelon ruptures under tension.

Abstract: Efficiency of the modern network of seismological observations in Vietnam is estimated, and an optimal design of planning network, consisted of 14 seismic stations is proposed. At the same sensitivity of network, but with a less number of stations, the new network would enable to determine hypocenter parameters in a more precise at a more uniform distribution of errating band within observation area.

Abstract: The initial information and requirements for developing a seismologic observation system and data-processing and transfer tools for a tsunami warning system and its functions and tasks are considered. The structure of the seismologic observation system for the tsunami warning service (TWS) in the Russian Far East is proposed. A study of general technical and methodological problems is carried out to increase the efficiency for urgent tsunami prediction from continuous seismic monitoring data of territories of the Russian Far East and the world. Special attention is paid to the problem of tsunami prediction from seismologic data on strong earthquakes in near zone of a protected territory (up to 200 km).

Abstract: The high-voltage rectifier is described developed for the Energy-2 generator, with a capacity of 200 kW in which a step-up power transformer is used as a converter. The Energy-2 generator is intended for solving problems of precision deep electromagnetic monitoring of seismoactive regions of the Earth’s crust to find earthquake precursors. Theoretical investigation and numerical simulation of the high-voltage rectifier are carried out and parameters of its elemental base are optimized. All the high-voltage rectifier components, heat sink, and forced cooling system were manufactured on the basis of the developed documentation. The high-voltage rectifier was successfully tested as part of the“Energy-2 generator in August 2009 during the “FENIKS-2009” experiment.

Abstract: Merits and demerits of recording of seismic signals at the bottom of water areas are considered. It is shown that long-term seismological monitoring systems should be placed in the regions of industrial development of the shelf and continental slope and in the areas of high seismic and tsunami hazard of oceans and seas. The results obtained during expeditions of the Shirshov Institute of Oceanology of the Russian Academy of Sciences with the use of broadband bottom seismographs are reported. Autonomous bottom seismographs with long-term operation at the bottom and operative communication via satellite and radio channels are proposed for the formation of a marine seismological network.

Abstract: The intensity of the earthquake of August 27, 2008 registered 7–8 points on the MSK-64 scale at its epicenter. It was the strongest earthquake in the Pribaikalie in the last 50 years. The main causes of damage in buildings were the considerable depreciation of their construction and the low quality of the construction. The most typical macroseismic characteristics were the failures of brick chimneys and of ovens in one- and two-story wooden buildings.

Abstract: In this article we have compared the results of seismotectonic and paleoseismogeologic investigations for representative segments of the two fold systems of the Alpine-Himalayan mobile belt (in the North- west Caucasus and West Himalayas). It has been found that during the previously identified “seismic gaps,” in both cases, we are dealing with primary dislocations (seismic ruptures) of ancient historical and prehistoric strong earthquakes. According to estimations, the magnitude of one-act seismogenic displacements in the first region was about 6.5-7.0 m, and the recurrence period ranges from 500 to 1500 years on average. In the West Himalayas, the overthrust displacements along the ruptures were 6-7 m, which corresponds to an 8.0-magnitude earthquake. At the same time, the recurrence period of strong earthquakes during a seismic gap in the Himalayas was 500-1000 years, which is similar to that in the Caucasus. The data collected also demonstrate the correct preliminary estimation of the seismic potential of zones of seismic quiescence in both the studied fold systems.

Abstract: The principal features of the European Macroseismic Scale (EMS-98) are considered in terms of its applicability in Russia.

Abstract: Some aspects concerning collection and analysis of primary materials, on whose basis the Tambov (1954) and Tyumen’ (1926) earthquakes have appeared in the “New Catalogue...” [Novyi..., 1977] are discussed. Moreover, the regional catalogues of the Urals (1914–2002) and Kamchatka Region (1737–1899, 1900–1952) have been compiled.

Abstract: The formats of the different versions of the earthquake catalog of the Garm prognostic site area are described and unified. The catalog versions contain the results of detailed continuous seismic monitoring with a high sensitivity array of seismic stations carried out in 1955–1991. Format unification allowed for conjoint analysis of different catalog versions with unified software.

Abstract: In this work the possibility for precision three-fluidal hydrostatic level design is theoretically substantiated with effective compensation of the effects of temperature gradients along leveling trace, fluctuations of integral temperature of measuring system and its separate blocks, atmospheric pressure differences between stations, tilts of hydrostatic vessels and their working fluid level indication errors.

Abstract: The results of a survey of a number of objects in the field and towns of Nevelsk and Gornozavodsk, which were in the epicenter of an earthquake, are presented.

Abstract: A method of remote sensing of local electrical fields with a mosaic spread in the atmosphere is described. The proposed method is based on searching for sources of infrared radiation by scanning the atmosphere and on analyzing the radiation spectrum.

Abstract: The paper discusses microseismic monitoring during oil well stimulation by hydraulic fracturing, an emergent technology used for hydraulic fracturing layer control. The passive monitoring is a new widely developing technology of HFL control. The main factor affecting the results of passive seismic monitoring is the event location accuracy. The passive monitoring acquisition system utilizes one three components seismic probe deployed into the observation well. To evaluate the location accuracy of induced events for one observation well we applied traditional kinematic approach based on picking of earthquake P- and S-waves arrivals. The influence of geometric parameters of geophones location in a borehole, their quantity, picking errors of waves arrivals on the accuracy of microearthquakes location is studied.

Abstract: The true or full ground motion information is frequently necessary in seismology to deal with a wide range of urgent scientific and applied problems; this information includes knowledge not only of ground motion along three axes at the recording site, but also the values of tilt or rotations of the surface at the site. This problem is usually attacked using a special type of seismic instrument-tiltmeters. Gyrotiltmeter is one of the many types of tiltmeters in which the gyroscope is used as the active sensor. The main obstacle in the way of developing effective long period seismic instruments, including gyrotiltmeters, consists in various sorts of noise, frequently not of seismic origin, which influence on the instrument increases as its frequency characteristic is extended toward longer periods. The present paper is concerned with problems arising in the use of optimal filters to detect seismic signals in records of a gyrotiltmeter where also noise may be present, e.g., that due to air pressure fluctuations. Examples are provided of tests of the algorithms, which clearly demonstrate that the application of the optimal filters to records of long period gyrotiltmeter channels can significantly enhance the signal/noise ratio to detect seismic signals disguised by induced noise.

Abstract: The specialized station of high-frequency seismic noise registration “Nachiki” is described arranged on Kamchatka in 1987. The instrument-methodical aspects of registration are considered, as well as history of observations development. New principal experimental results of surveys are represented. The results of use of high-frequency seismic noises are summarized to reveal strong earthquake precursors in the online mode in 1996–2008.

Abstract: The paper considers the problem of how Russian and European researchers of the 19th century became acquainted with the sources of the information about earthquakes in the Urals. Particular attention is devoted to the earliest known event in 1693. It is shown that this earthquake was mistakenly related to the Urals due to the primary source not being learned; in fact, it was fixed in Transbaikalia. The problem is posed about the need for professional work with historical materials and cataloging the events of the historical past.

Abstract: The results of experimental observations over variations of the Earth’s magnetic field recorded by the instruments of the North Caucasus Geophysical Observatory are presented. We observed specific ultralow-frequency quasi-oscillatory waveforms preceding strong distant seismic events in the structure of electromagnetic signals.

Abstract: The development of a new broadband seismometer should begin with preliminary theoretical study that includes, first of all, the investigation of noise which is expected to be generated by the device under the action of fluctuations of environmental factors. This noise limits a frequency band of devices from the long-period side and their dynamic range from below. Experimental determination of the noise characteristics of the existing broadband seismometers is limited by a microseism level in the places where the devices are installed. In view of this, the theoretical study of noise generating factors and channels of noise generation is of special importance. One of the main noise generating factors of the broadband seismometers is the ambient temperature variation. One of the types of temperature noise is the variation in linear dimensions of device elements perceived by a seismosensor as ground vibration. In this study, the estimates are presented which make it possible, first, to clarify which elements of the device are the most sensitive to the ambient temperature variations and, consequently, insert the most noise to seismic recording and, second, to determine the level of noise generated by all the elements. The frequency dependence of apparent motion of the Earth on structural dimensions and materials of the device is expressed in general form.

Abstract: On an instrumental complex of SRI NAO, by anomalous great deviations on the course of Fedchenko clock, seismic waves are revealed caused by some large earthquakes (the Kurils, Pakistan, Indonesia, the Molucca Sea, Turkey, Greece, etc). Several minutes before a seismic wave arrival, decrease of dispersions of Fedchenko astronomical clock readings presumably caused of an infra low frequency electromagnetic radiation from an epicenter of earthquake was observed.

Abstract: The conventional radiocarbon ages of soil horizons limiting the timing of six fault-generating dis- placements within the East Sayan structure of the Main Sayan Fault and four displacements within the Tora structure of the Tunka Fault (M > 7) have been calibrated according to the IntCal04 calibration curve. It was revealed that between time periods of 12 Ka and 5.4 Ka years ago, the recurrence of earthquakes associated with movements along the faults in the East Sayan structure occurred once every 3000 years. After seismic quiescence, since 1100 years, one earthquake has occurred every 440 years. Using the Monte Carlo method, the possibility of the recurrence of strong earthquakes at different probability levels was considered. At a fre- quency probability of 95% the Main Sayan fault may be hazardous, dating from about 2120 AD. When low- ering the threshold probability to 72%, the beginning of the period of potential hazard is reduced to about 2030 AD. In both cases the maximum possibility of the occurrence of the next strong earthquake is not earlier than in the 22nd century. For the Tora structure, the periodicity of the recurrence of the earthquakes was esti- mated as 2800 yearsfor the past 11Ka with a probability of over 95% of the recurrence of earthquakes. This allows us to assume that currently the Tora structure is within the time interval of the potential risk of the recurrence of a strong earthquake.