Zurab Javakhishvili

• Ilia State University

Instrumental seismic monitoring has a long history in the Caucasus and started in 1899 when the first seismograph was installed in Tbilisi, Georgia. Much of the analog paper records from this time period are preserved in the Tbilisi archives because Georgia served as the regional data center. In the 1990s, due to the collapse of the Soviet Union an...

Cenozoic magmatism in the Caucasus-Iran-Anatolia (CIA) region can simply be divided into two main stages that pre-and postdate , respectively, the onset of the Arabia-Eurasia collision. The pre-collisional stage, active from the Eocene to Oligocene, has been generally related to the northward subduction of Neotethyan oceanic lithosphere. The post-c...

Since Plio-Pleistocene time, southward migration of shortening in the eastern part of the Greater Caucasus into the Kura foreland basin has progressively formed the Kura fold–thrust belt and Alazani piggyback basin, which separates the Kura fold–thrust belt from the Greater Caucasus. Previous work argued for an eastward propagation of the Kura fold...

Since the Plio-Pleistocene, southward migration of shortening in the eastern part of the Greater Caucasus (GC) into the Kura foreland basin has progressively formed the Kura-Fold Thrust belt (KFTB) and Alazani piggyback basin, which separates the KFTB from the GC. Previous work argued for an eastward propagation of the KFTB, implying that the weste...

We present and interpret newly determined site motions derived from GPS observations made from 2008 through 2016 in the Republic of Georgia, which constrain the rate and locus of active shortening in the Lesser–Greater Caucasus continental collision zone. Observation sites are located along two ∼160 km-long profiles crossing the Lesser–Greater Cauc...

Comparison of plate convergence with the timing and magnitude of upper-crustal shortening in collisional orogens indicates both shortening deficits (200-1700 km) and significant (10-40%) plate deceleration during collision, the cause(s) for which remain debated. The Greater Caucasus Mountains, which result from post-collisional Cenozoic closure of...

In the present study we investigated the character of variation of long-range correlations features in earthquakes' temporal and spatial distribution in Caucasus. Scaling exponents of data sets of interearthquakes time intervals (waiting times) and interearthquakes distances were calculated by method of Detrended Fluctuation Analysis (DFA). Scaling...

Current study concerns Javakheti area in the Lesser Caucasus. This area comprises a volcanic plateau with more than 20 volcanoes, several of them dated as having erupted during the Holocene. In the region the upper part of Lava complex is represented by Middle-Upper Quaternary formations. The region is an area of young deformations in the Alpine be...

In the present research we investigate variation of scaling features of earthquakes’ temporal and spatial distribution in Caucasus from 1960 to 2014. Data sets of waiting times and interearthquakes distances were obtained from the original and declustered Caucasus catalogues. For the assessment of long-range time-correlations of used data sets the...

Relative ages of late Cenozoic stratigraphy throughout the Caspian region are referenced to regional stages that are defined by changes in microfauna and associated extreme (>1000 meter) variations in Caspian base level. However, the absolute ages of these stage boundaries may be significantly diachronous because many are based on the first occurre...

Investigation of complex dynamics of ambient seismic noise remains as an important scientific research challenge. In this work we investigated dynamical features of the ambient noises at Oni seismic station, Georgia. We used stochastic model reconstruction method from measured data sets. Seismic records for different time periods around Oni seismic...

We analyzed the fractal and multifractal properties of the earthquake time series occurred around the Enguri dam in West Georgia by applying the methods of detrended fluctuation analysis and multifractal detrended fluctuation analysis. We examined the interevent time series in two periods: (1) 1960–1980, in which the investigated area was character...

Current study concerns Javakheti area in the Lesser Caucasus. This area comprises a volcanic plateau with more than 20 volcanoes, several of them dated as having erupted during the Holocene. In the region the upper part of Lava complex is represented by Middle-Upper Quaternary formations. The region is an area of young deformations in the Alpine be...

Investigation of dynamical features of ambient seismic noise is one of the important scientific and practical research challenges. We investigated scaling features of the ambient noises at the Oni seismic station, Georgia, using detrended fluctuation analysis method. Data from this seismic station, located in the epicentral zone of Oni M6.0, 2009,...

The Caucasus is a region of active tectonics and complex crustal structure located between the Caspian Sea to the East and the Black Sea to the west. To the North is the aseismic Eurasian shield and to the South-West and the South are the active tectonic regions of East Anatolia and the Zagros thrust and fault belt of Northwestern Iran. Main intere...

Current presentation concerns investigation of Javakheti seismically active fault (Georgia, South Caucasus region) by means of Geophysical prospecting methods, carried out during the past two years. The named fault represents the major seismo tectonic structure at Javakhety volcanic highland. Fault segments at some places are well expressed on surf...

Seismic hazard analysis in the last few decades has become a very important issue. Recently, new technologies and available data have been improved that have helped many scientists to understand where and why earthquakes happen, the physics of earthquakes, etc. Scientists have begun to understand the role of uncertainty in seismic hazard analysis....

The distribution of earthquake magnitudes in the Javakheti highlands was analyzed using a non-extensive statistical approach. The earthquakes occurring from 1960 to 2008 in this seismically active area of Southern Caucasus were investigated. The seismic catalog was studied using different threshold magnitude values. Analyses of the whole time perio...

Seventy-two local earthquakes were analyzed and the quality factor (Q(c)) was calculated for three regions of Georgia using the single-scattering model in the frequency range of 1-32 Hz. Standard International Association of Seismology and Physics of the Earth's Interior (IASPEI) routines for the coda Q(c) determination have been used. The coda win...

For estimating fatalities and injured within minutes after an earthquake worldwide, we rely on real-time teleseismic determinations of epicenters. To estimate the teleseismic location errors, we computed the difference between the local epicenters of the dense seismograph networks of Japan, Italy, and Taiwan with those given by the PDE, those distr...

For last several years nonextensive statistical mechanics is increasingly used to study wide range of complex phenomena exhibiting the scale free nature in different domains. It is assumed that nonextensivity concepts may provide a suitable framework to shed new light on features of spatiotemporal and energetic behavior of seismic processes which p...

We present the first combined analysis of zircon U-Pb and Hf isotopes of intrusive bodies in the Georgian Caucasus that indicates a significant period of magmatism in the Carboniferous. Magmatic zircons of 14 intrusive rocks from the Georgian Caucasus show similar 206Pb/238U ages clustering between 309 and 331 Ma and ɛHf(T) values ranging from -0.1...

Predicting singular/extremal phenomena exceeding certain spatial, temporal, or energetic scales remains as a main scientific and practical challenge. The question is: does modern geophysics - based on recent progress in theories of complex systems and nonlinear dynamics - provide useful scientific insights to mechanisms underlying disastrous extrem...

The seismic hazard of eastern Georgia has been computed with the seismotectonic probabilism approach. A logic tree was used to take into account the different hypotheses on the seismogenesis of the Caucasus region, and to model seismicity and attenuation. In addition to the usual maps referring to different types of terrains (rock, stiff, and soft...

It took more then a century for mankind first to understand a nature of most devastating catastrophes on the earth - earthquakes and then to reach more or less realistic seismic hazard assessment for particular regions. Seismic observations in the Caucasus had started in the end of XIX century. In 1899 the Tiflis (now Tbilisi) seismic station has b...

The Caucasus is one of the most active segments of the Alpine-Himalayan collision belt. We used the catalog data of Georgian Seismic Network to calculate the reference 1-D and 3-D P-velocity model of the Caucasus region. The analog recording period in Georgia was quite long and 17,000 events reported in the catalog between 1956 and 1990. We careful...

Tbilisi (Capital of the republic of Georgia) has largely been spared of large destructive earthquakes. The maximum affect from historical earthquakes in the Tbilisi area has not exceeded macroseismic Intensity 7 (MSC scale). There is very sparse information with which to identify the location of these earthquakes. The active seismogenic structures...

It was reported earlier that water level periodic variation in a high dam reservoir may lead to the synchronizing influence on local seismic activity. Taking into account that phase synchronization is not related to strong functional relationships, in the present study small dynamical changes in seismic activity caused by water level variation were...

We present an evidence of reservoir induced controlling influence of water level periodic changes in Enguri high dam reservoir on regional seismic activity. Data sets of water level daily variations in the Enguri high dam reservoir and the seismic data sets recorded by the local network have been analyzed. Monthly frequency of earthquake occurrence...

The reservoir-induced changes of the regional seismic activity around the Enguri high dam reservoir in western Georgia are found to be influenced by the water level of the reservoir.The water level variations of the Enguri high dam reservoir and the seismic data sets recorded by the local network have been analyzed by means of statistical, linear,...

AIP Conference Proceedings 825(1), 147 (2006) DOI: http://doi.org/10.1063/1.2190748

AIP Conference Proceedings 825(1), 141 (2006) DOI: http://doi.org/10.1063/1.2190743

We apply a physically based approach to synthesize possible ground motion from future earthquakes within and near Tbilisi, capital of the Republic of Georgia. We utilize earthquake locations, focal mechanisms and moment tensor inversion to better identify the possible fault locations. We develop a suite a ground motions that can be expected from ea...

In the present study we have compiled probabilistic seismic hazard maps of the Tbilisi area; for different parameters (macroseismic intensity, PGA, SA) and different probabilities. The hazard is dominated by the geometry of the seismic source zones that are situated in the immediate vicinity of the city. The northern part of the city, according to...

We have evaluated the dynamical properties of the temporal distribution of the small earthquakes. Two main goals of the investigation were: (a) a qualitative evaluation of the nonlinear structure of the time distribution of earthquakes, taking place before and after the strongest Caucasian events; (b) a quantitative discrimination of the dynamics (...

Errors in earthquake hypocenter determination is inevitable fact due to quite a large unhomogeneities in Earth’s structure. While hypocenter distribution carries valuable information about earthquakes source zones, their geometry and activity. Also energy release at different sections could be determined. The main purpose of current study was to tr...

It is well known that lithospheric seismic processes are characterized by self-similarity or scale invariance in terms of earthquake-size, time, space and space-time distributions, although precise details of underlying dynamics are not clear. In this study we apply nonlinear dynamics theory tools, such as a correlation dimension, "surrogate" data...

The paper describes the permanent digital accelerograph network in the Caucasus area operated by the National Survey for Seismic Protection of the Republic of Armenia, the Georgian Academy of Sciences and the Swiss Seismological Service and granted by the Swiss Disaster Relief. The network, which became operational in 1990 and since then gradually...

There are two main connections between seismicity and the state of cultural monuments in earthquake prone countries. The first one is connected with using both historical chronicles and results of revision of monuments for parameterization of ancient earthquakes, namely, for reconstruction of date, location of epicenter, definition of hypocenter de...

The probabilistic seismic hazard maps has been constructed for the territory of Georgia. Cornell approach, namely computer program SEISRISK III after Bender and Perkins 1987, was used for calculations. Three main elements were used for seismic hazard analysis following the Cornell approach: definition of seismic source zones (SSZ), parameters of se...