Mikheil Elashvili

• PhD
• Professor at Ilia State University

On the Vardzia unique cave city of the 12th century combining an urban, defensive, and monastic complex hewn into the volcanic tuff flow of andesitic-dacitic composition. It is an important monument of Georgian cultural heritage is in danger of gradual natural destruction and earthquake hazards.

In the midlatitudes of the planet, we are facing the imminent disappearance of one of our best high-resolution (pre)historic climate and anthropogenic pollution archives, namely the loss of glacial ice, through accelerated global warming. To capture these records and interpret these vanishing archives, it is imperative that we extract ice-cores fro...

Due to its location between Mesopotamia and the Eurasian steppes, the southern Caucasus occupies a distinctive place in Old World archeology. While several local areas in the South Caucasus have shown a complex social organization with fortified structures during the Late Bronze Age and Early Iron Age (LBA–EIA), the Shiraki Plain (southeast Georgia...

Lake Paravani, located on the volcanic Javakheti Plateau in the central part of the Lesser Caucasus at 2073 m a.s.l., forms a unique geo‐bio‐archive for palaeoenvironmental reconstructions in this remote region. Based on sediment cores from the southwestern part of the lake we expand the existing palynological and sedimentological records beyond th...

Along the lower course of the Rioni and several minor rivers, more than 70 settlement mounds (local name: Dikhagudzuba ) have been identified by field surveys and remote sensing techniques. They give evidence of a formerly densely populated landscape in the coastal lowlands on the Colchian plain (western Georgia) and have been dated to the Bronze A...

Many of the Georgian cultural heritage sites consist of rupestrian monastic complexes constructed between the sixth and the 12th centuries of exceptional universal value from a historical, cultural, and natural point of view. Many of them are affected by hydrogeological problems and require the planning of an effective risk mitigation strategy. Thi...

We present a spatiotemporal picture of human genetic diversity in Anatolia, Iran, Levant, South Caucasus, and the Aegean, a broad region that experienced the earliest Neolithic transition and the emergence of complex hierarchical societies. Combining 35 new ancient shotgun genomes with 382 ancient and 23 present-day published genomes, we found that...

RUSSIAN COPY: the Online Journal GeoInfo (https://geoinfo.ru) translated and published our Springer Nature Group article in Rock Mechanics and Rock Engineering (https://lnkd.in/d3tGu4UV) in two parts in two separate issues: ORIGINAL: https://lnkd.in/dcbXkZ58 (Springer, RMRE) OKT 2022: https://lnkd.in/dc6J2F9h (GeoInfo) NOV 2022: https://lnkd.in/dBA...

RUSSIAN COPY: the Online Journal GeoInfo (https://geoinfo.ru) translated and published our Springer Nature Group article in Rock Mechanics and Rock Engineering (https://lnkd.in/d3tGu4UV) in two parts in two separate issues: ORIGINAL: https://lnkd.in/dcbXkZ58 (Springer, RMRE) OKT 2022: https://lnkd.in/dc6J2F9h (GeoInfo) NOV 2022: https://lnkd.in/dBA...

These data contain supplementary data [input parameters for hydrological modeling, drilling core descriptions, analytical data, paleoecological data, unbiased trench photos, photos of thin sections and paeoecological finds, figure of regional tectonic pattern] of the article Suchodoletz et al. (2022): Human-environmental interactions and seismic ac...

Long-term human-environmental interactions in naturally fragile drylands are a focus of geomorphological and geoarchaeological research. Furthermore, many dryland societies were also affected by seismic activity. The semi-arid Shiraki Plain in the tectonically active southeastern Caucasus is currently covered by steppe and largely devoid of settlem...

This study assesses the static stability of the artifcial Sabereebi Cave Monastery southeast of Georgia's capital, Tbilisi. The clif into which these Georgian-Orthodox caverns, chapels, and churches were carved consists of a fve-layered sequence of weak sedimentary rock—all of which bear a considerable failure potential and, consequently, pose the...

Il presente lavoro sintetizza le recenti attività di supporto all’Agenzia per la Protezione del Patrimonio della Georgia per l’analisi e la mitigazione dei fenomeni di instabilità che affliggono i monasteri rupestri della nazione. Più nello specifico, vengono presentati i risultati delle campagne di indagine degli ultimi due anni (giugno 2017 – nov...

Study of past changes in environment and, its effect on human society delivers key information to reconstruct the hystorical past but also to project future changes and their effects. Study focus on South-East Georgia, Caucasus region, which represents natural polygon of long term changes in the environment. Study area represents semi-arid Shiraqi...

Rock-carved cultural heritage sites are often developed in slopes formed by weak rocks, which due to their peculiar lithological, geotechnical, and morpho-structural features are characterized by excellent carvability, which at the same time makes them prone to weathering, deterioration, and slope instability issues. In this context the use of adva...

The present paper describes the recent support activities implemented during the fall of 2018 in the David Gareja monastery complex area (South-eastern Georgia). During last decades, the growing cultural interest in the Georgian rock hewn monasteries founded in the sixth century has been constantly accompanied by conservation and management problem...

The rock-cut city of Vardzia is an example of the extraordinary rupestrian cultural heritage of Georgia. The site, Byzantine in age, was carved in the steep tuff slopes of the Erusheti mountains, and due to its peculiar geological characteristics, it is particularly vulnerable to weathering and degradation, as well as frequent instability phenomena...

In the southernmost part of the Colchian plain (Georgia), the Supsa and Rioni rivers represent important catchments for reconstructing Holocene landscape changes. Using granulometric methods, geochemical analyses and radiocarbon dating, we demonstrate that significant palaeoenvironmental changes have taken place in the surroundings of the Supsa fan...

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The cover image, by Hannes Laermanns et al., is based on the Research Article Bronze Age settlement mounds on the Colchian plain at the Black Sea coast of Georgia: A geoarchaeological perspective, DOI: 10.1002/gea.21670.

The rock-cut city of Vardzia is a cave monastery site in southwestern Georgia, excavated inside the volcanic and pyroclastic rock layers of the Erusheti mountain on the left bank of the Mtkvari river. The main period of construction dates back to the second half of the twelfth century. The site has been affected by frequent instability phenomena al...

Situated between the Enguri and Khobistskali rivers, more than 30 settlement mounds (locally named Dikhagudzuba) provide evidence for a relatively densely populated landscape in the coastal lowlands of western Georgia during the Bronze Age. Compared to older mounds in eastern Georgia and other regions, these mounds differ not only in age but also i...

The Kolkheti lowlands (Colchis, Colchian plain) form the central part of the extensive coastal lowlands along the Black Sea coast of Georgia. Situated between the Greater and the Lesser Caucasus, favourable climatic conditions resulted in a constant human occupation of the region during the Holocene. However, due to continued deltaic sedimentation...

The Caucasus defines the northern margin of the Arabia-Eurasia collision zone between the Black and Caspian Seas, within the Alpine Himalayan collision. Most orogen perpendicular convergence within this sector of the Arabia-Eurasia collision is absorbed within the Greater Caucasus, as indicated by seismicity, GPS velocity gradients and Neotectonic...

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...

Vardzia is a unique cave city of the 12th century combining an urban, defensive, and monastic complex hewn into the volcanic tuff flow of Pliocene andesitic-dacitic composition. In 1283, after a strong earthquake, the cave complex was severely damaged, but it did not cease operation. Results of geological investigation showed that the Vardzia area...

Seismic hazard assessment is a very important issue for seismic design and engineering projects. Generally, probabilistic seismic hazard assessment (PSHA) is used for such kind of studies, which gives a probabilistic description of earthquake characteristics such as selected ground motion parameter (peak ground acceleration or spectral acceleration...

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...

Abstract: Close range digital photogrammetry, which involves the application of unmanned aerial vehicle (UAV), has been used in a growing number of diverse applications across different scientific disciplines. Our objective was to use the mentioned method in the survey of the contemporary geoecological conditions of the coastal area on the example...

Abstract: Close range digital photogrammetry, which involves the application of unmanned aerial vehicle (UAV), has been used in a growing number of diverse applications across different scientific disciplines. Our objective was to use the mentioned method in the survey of the contemporary geoecological conditions of the coastal area on the example...

Recognizing the fact that we are living in a constantly changing world became actual during the last decades, and promoted numerous studies related to the environmental consequences of climate change and human impact. In this context, the study of human- and naturally-triggered palaeoenvironmental changes leads to a better understanding of possible...

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...

In the paper, the results of laboratory experiments on the electromagnetic (EM) initiation of mechanical instability (slip) are presented. Series of strong EM pulses were applied to the mechanical system driven close to the critical state, namely, to the (dry) rock samples placed on an inclined supporting sample at the slope angle less than, but cl...

The semi-arid Gareja region in the Iori Highland in the southeastern part of the Republic of Georgia is characterized by an annual precipitation < 500 mm and shows an open steppic landscape today. As is known from historical sources, the landscape showed the same character already during the 6th century AD when the Gareja monastery located in the c...

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...

The project “Institutional Building for Natural Disaster Risk Reduction (DRR) in Georgia” was implemented by the Caucasus Environmental NGO Network (CENN) and the Faculty of Geo- Information Science and Earth Observation (ITC), University of Twente, the Netherlands. The project was financially supported by the Social Transformation Programme for Ce...

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...

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...

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...

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 paper, the results of laboratory experiments on the electromagnetic (EM) initiation of mechanical instability (slip) are presented. Series of strong EM pulses were applied to the mechanical system driven close to the critical state, namely, to the (dry) rock samples placed on an inclined supporting sample at the slope angle less than, but cl...

A b s t r a c t In the paper, the results of laboratory experiments on the electromagnetic (EM) initiation of mechanical instability (slip) are presented. Series of strong EM pulses were applied to the mechanical system driven close to the critical state, namely, to the (dry) rock samples placed on an inclined supporting sample at the slope angle l...

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...

The paper is related to Wavelet transform and its applications in seismic data analysis, namely for interpretation of seismograms. Wavelet transform is a new, efficient tool of time series analysis, providing us with time-frequency decomposition of complicated signals in a form of seismic waves. Transforming time series to time-frequency domain mak...

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...

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...