This paper studied the effects of Coulomb stress in understanding the proximity to failure on the... more This paper studied the effects of Coulomb stress in understanding the proximity to failure on the Palu-Koro fault system. An earthquake occurred on a large strike-slip fault in the northern part of Sulawesi Island, Indonesia, on September 28, 2018. Coulomb stress increased by approximately 1 bar, corresponding closely to the locations of aftershocks and areas where stress dropped by more than 10 bars. Based on the focal mechanisms of the aftershocks and source models of the main shock, the coulomb failure stress changes on both of the focal mechanism nodal planes are calculated. Additionally, we calculated the changes in Coulomb stress on the focal sources of each aftershock. Our stress model indicates a positive correlation within the areas of extended Coulomb stress caused by the combination of seismic activities. We investigated the Coulomb stress as a possible origin for the aftershocks, which are most likely to slip optimally oriented for failure due to the local stress field generated by the mainshock. The Palu 7.5 earthquake led to the distribution of surface displacements. Moreover, calculated horizontal displacement increased in the NW-SW direction, ranging from 1 to 1.3 meters. The stress maps included in this paper are crucial in predicting the expected locations of future aftershocks and mitigating the potential for earthquakes.
<p>In this research, the Interferometric Synthetic Aperture Radar (InSAR) method is... more <p>In this research, the Interferometric Synthetic Aperture Radar (InSAR) method is used to evaluate the connection between earthquakes and volcano dynamics in Azerbaijan. InSAR provides a robust technique for defining the complexity of earthquakes in spatial dimensions and provides more precise information about the effects of earthquakes than traditional methods. We assessed pre-, co-, and post-seismic scenarios to find the possible triggering relationships between moderate earthquakes and the Ayazakhtarma mud volcano. The Ayazakhtarma volcano is located 46 km from the 2021 Shamakhi and 67 km from the 2019 Basqal earthquakes, respectively. In this study, comprehensive deformation time series and velocities for the volcano using Sentinel 1A/B data between 2014 and 2022 were produced from LiCSAR products using LiCSBAS. At the same time, a radar line-of-sight (LOS) displacement map was generated based on results from the GMT5SAR for pre-, co-, and post-seismic deformation of earthquakes. Based on our observations of the following earthquakes, our results show that moderate earthquakes (Mw≤5) cannot trigger large mud volcano eruptions. In particular, the study of the Ayazakhtarma mud volcano revealed significant LOS changes that were positive and negative in the western half and eastern half of the site, respectively. Our research helps us comprehend how earthquakes impact eruptive processes. In two different situations, the interferograms enable the detection of ground displacement associated with mud volcano activity. At the Ayazakhtarma, faults also play a fairly important role in the deformation pattern. Interestingly, the observed fault system primarily exists in the region that divides sectors with various rates of subsidence. The interferometric data have been studied, providing new information on the deformation patterns of the Ayazakhtarma mud volcano.</p>
<p>To track global environmental change and evaluate the risk to sustainable develo... more <p>To track global environmental change and evaluate the risk to sustainable development, analysts and decision-makers in government, civil society, finance, and industry need the fundamental geospatial data products known as Land Use and Land Cover Change (LULCC) maps. Our research studied LULCC variations in a timeframe of 5 years in the Gabala district. Sentinel 2 open-source products were used to compare and categorize the procedure over one-year time intervals. For this investigation, the discrete indexing method was developed and used. The approach we used was focused on obtaining multiple indices and using them to improve classification performance. The Normalized Difference Vegetation Index (NDVI), Modified Normalized Difference Water Index (MNDWI), Bare Soil Index (BSI), Normalized Difference Tillage Index (NDTI), and Salinity Index (SI) are the indices evaluated. The most crucial variables were determined and classified using the random forest classifier in LULCC. The Sentinel Application Platform of the European Space Agency (SNAP ESA) algorithm was used to analyze the process and performed over 90% accurate predictions when applied to the testing dataset. Results revealed that using the RS technique, time and cost-efficient analyses are possible and reliable for developing socioeconomic and ecological growth strategies.</p>
The Eastern Mediterranean and Caucasus regions are two of the most seismically active deforming c... more The Eastern Mediterranean and Caucasus regions are two of the most seismically active deforming continental regions. Monitoring and studies of the extensive deformation processes in this comparatively limited region enhance our understanding of the continental collision in the region. In this paper, we built a new elastic block model to constrain present-day plate motions and regional deformation in the intraplate zone and estimate fault slip rates from a dense global positioning system (GPS) velocity field. We additionally considered differences in moment accumulation rate per unit fault length using seismogenic and geodetic depth along the main faults. The right-lateral slip rates were estimated at between 24.33 ± 0.47 and 28 ± 0.5 mm/year along the North Anatolian Fault Zone (NAFZ) and the left-lateral slip at 10.6 ± 0.9 to 12 ± 1 mm/year on the East Anatolian Fault Zone (EAFZ). The Dead Sea Transform Fault (DSTF) slip rate ranges between 4.1 ± 0.95 and 6 ± 1 mm/year. The slip rate for the Main Caucasus Thrust Fault (MCTF) is 6.5 ± 0.2 to 14.3 ± 0.7 mm/year from west to the east. A shallow locking depth of 9 ± 3.2 km was found in the Marmara region. The locking depth along the DSTF is 10.9 ± 5.5 km in the northern segment, 9 ± 6.7 km in the central section and 11.8 ± 4 km in the southern section. The locking depth of the EAFZ is 16.7 ± 4.4 km in the northern segment, 19.8 ± 7.4 km in the middle segment and 12.5 ± 4.2 km in the southern segment. The locking depths along the MCTF range between 12.7 ± 5.8 and 17.8 ± 4.9 km from west to east. Our new block model has the best fit to the observed velocities. The results provide an overall understanding of fault activity and have implications for the earthquake hazard along the main faults in the region.
In this study, a comprehensive statistical analysis was made for different parts of the world. Fo... more In this study, a comprehensive statistical analysis was made for different parts of the world. For this purpose, fundamental seismotectonic earthquake parameters such as b-value, magnitude completeness, Mc-value stress distribution and moment release were analysed and their interrelationship was investigated. In this context, for the evaluation of earthquake hazard potential, spatial variations of these fundamental parameters were achieved for the Eastern Mediterranean and Caucasus since there do not exist detailed studies including these parameters for these regions of the world. The high-resolution maps of the b-value, Mc-value and stress variance were analysed in the different seismotectonic regions in the Eastern Mediterranean and Caucasus. This study considers the spatial anomalies and correlation models between the b-value, faulting styles, and stress regime and moment release. Lower b-values (b ≤ 1) were observed along with the Main Marmara Fault, eastern Turkey, western Alborz, northern Zagros, south-east Iran and the north-east Caucasus, and these small b-values indicate the active seismic region. Mc level in most of Turkey is in and around 2.8. However, Mc-value is about 3.0 in the Caucasus and about 3.5 level in Iran.
This work also includes a stress inversion map in the region based on the focal mechanisms. The normal, strike-slip and a few thrust fault solutions were observed in the research areas. The results show that a combination of these parameters may supply preliminary tools for future researches. Consequently, the spatial pattern of the b-values, moment releases and stress regimes can be used as considerable promise for the predicting of forthcoming seismic hazard regions.
The Eastern Mediterranean and Caucasus regions are two of the most seismically active deforming c... more The Eastern Mediterranean and Caucasus regions are two of the most seismically active deforming continental regions. Monitoring and studies of the extensive deformation processes in this comparatively limited region enhance our understanding of the continental collision in the region. In this paper, we built a new elastic block model to constrain present-day plate motions and regional deformation in the intraplate zone and estimate fault slip rates from a dense global positioning system (GPS) velocity field. We additionally considered differences in moment accumulation rate per unit fault length using seismogenic and geodetic depth along the main faults. The right-lateral slip rates were estimated at between 24.33 ± 0.47 and 28 ± 0.5 mm/year along the North Anatolian Fault Zone (NAFZ) and the left-lateral slip at 10.6 ± 0.9 to 12 ± 1 mm/year on the East Anatolian Fault Zone (EAFZ). The Dead Sea Transform Fault (DSTF) slip rate ranges between 4.1 ± 0.95 and 6 ± 1 mm/year. The slip rate for the Main Caucasus Thrust Fault (MCTF) is 6.5 ± 0.2 to 14.3 ± 0.7 mm/year from west to the east. A shallow locking depth of 9 ± 3.2 km was found in the Marmara region. The locking depth along the DSTF is 10.9 ± 5.5 km in the northern segment, 9 ± 6.7 km in the central section and 11.8 ± 4 km in the southern section. The locking depth of the EAFZ is 16.7 ± 4.4 km in the northern segment, 19.8 ± 7.4 km in the middle segment and 12.5 ± 4.2 km in the southern segment. The locking depths along the MCTF range between 12.7 ± 5.8 and 17.8 ± 4.9 km from west to east. Our new block model has the best fit to the observed velocities. The results provide an overall understanding of fault activity and have implications for the earthquake hazard along the main faults in the region.
Physics of the Earth and Planetary Interiors , 2019
Coulomb stress variations may trigger earthquakes, while the stress transfer process is not clear... more Coulomb stress variations may trigger earthquakes, while the stress transfer process is not clear. In this paper, Coulomb stress changes are investigated for the sequences of strong earthquakes in the Caucasus region, which followed the 1988 M w 6.8 in Spitak, the 1991 M w 6.9 in Racha and the 2000 M w 6.2 in Baku. Our results show that the mainshocks induced variations in the stress field where most of the seismic events occurred. Coulomb stress increases 2 bars corresponding nearly to places of aftershocks, while the stress falls above 10 bars for Racha mainshock. The calculated Coulomb stress loaded about 5 bars at the end of rupture plane and the stress falls ~9 bars for Spitak mainshock. Our stress pattern shows a correlation within the areas of Coulomb stress caused by the combination of seismicity. Correlations between the coseismic Coulomb stress changes and the observed spatial patterns of the aftershocks created by the mainshock are illustrated by the stress variations over both optimally oriented and specified fault planes. An apparent correlation between the mainshock stress changes and the detected spatial pattern of the aftershocks is found, confirming the utility of the stress maps in constraining the expected locations of the forthcoming aftershocks and mitigating earthquake hazards.
The Eastern Mediterranean and Caucasus are located among the Eurasian, African and Arabian plates... more The Eastern Mediterranean and Caucasus are located among the Eurasian, African and Arabian plates, and tectonic activities are very complex. In this paper, the kinematics and strain distribution in these regions are determined and investigated from dense GPS observations with over 1000 stations and longer observations. The elastic block model is used to constrain present-day plate motions and crustal deformation. The relative Euler vectors between the Nubian, Arabian, Caucasus, Anatolian and Central Iranian plates are estimated. The Arabian-Eurasia, Anatolian-Eurasia, Nubian-Eurasia, Caucasus-Eurasia and Central Iranian Euler vectors are 0.584 ± 0.1 Myr À1 , 0.825 ± 0.064 Myr À1 , 0.35 ± 0.175 Myr À1 , 0.85 ± 0.086 Myr À1 and 0.126 ± 0.016 Myr À1. The strain rate in the East Mediterranean and Caucasus has been estimated from the GPS velocity field. The results show that the thrust dominated areas, the eastern Mediterranean-Middle East-Caucasus and Zagros have negative dilatation and the western Anatolia region has positive 2D dilatation rate with significant rotation. The west Anatolian shows the extension in NW-SE with about 150–199 nstrain/yr in the WE direction. The Central Anatolia shows compression rate below 50 nstrain/yr and extensional strain rate adjacent to East Anatolian Fault and Dead Sea Fault is about 0–100 nstrain/yr. The contraction strain rate is higher in Zagros and Caucasus between 100– 150 nstrain/yr and contraction orientation is along the NE-SW direction in Caucasus. The north part of Iran shows less contraction rate below 50 nstrain/yr but NorthEast Zagros Mountains, Tabriz fault and Chalderan fault show extensional rate between 50–110 nstrain/yr and principal axes rotation in the N-S direction. The maximum contraction observed in the Kopek Dag is about 100–194 nstrain/yr and orientated in the NE-SW direction. East Zagros Mountain and Makran subduction zone have a large clockwise rotation with 70–85 nradian and principal axes remains mostly along the N-S direction. The observed extension is along N-S by about 0–100 nstrain/yr with counter clockwise rotation in Dead Sea Fault. The Sinai block shows shortening rate in the range of 0–100 nstrain/yr.
In this study, ground response analysis on different 255 sites in Baku city of Azerbaijan was don... more In this study, ground response analysis on different 255 sites in Baku city of Azerbaijan was done. The damage distribution is estimated on the basis of local site effects. Aiming to estimate local site effect, analysis of the ratio of horizontal to vertical (H/V) spectra of microtremor records was performed. The records are conducted with the Guralp CMG-5TD accelerometer and, with the Nakamura's approach, dynamic characteristics of surface ground are estimated. The maps showing the distribution of the amplification and resonance frequency for the grounds of Baku city were produced, which demonstrate variability and heterogeneity of ground characteristics in the city. The results can be used for urban seismic hazard assessment researches in the future.
The decreasing sea level of the Caspian Sea is having a serious impact on coastal ecosystems and ... more The decreasing sea level of the Caspian Sea is having a serious impact on coastal ecosystems and biodiversity. This study, conducted over a decade from 2014 to 2023, provides a comprehensive analysis of the coastal transformations in the Gizil-Aghaj State Reserve, Azerbaijan, using remote sensing technologies. By utilizing a combination of optical and radar satellite data, we mapped the evolving interplay between land and sea. Our research reveals a significant coastline shift, with the Caspian Sea receding to expose an additional 218 km2 of land. This significant change was most apparent in the northeastern area, corresponding with regions experiencing substantial land subsidence. As the Caspian Sea's level decreases and the land sinks simultaneously, it's reasonable to expect that the shoreline would remain stable. In contrast to areas with land subsidence, places where the land is uplifting, along with the Caspian Sea's decreasing level, are likely to experience noticeable changes in their shoreline, suggesting a more dynamic and changing coastal area. These findings are crucial for understanding the fluctuations in the Caspian Sea level, likely influenced by a combination of natural geological processes, human activities, and broader climatic trends. The subsidence observed in some areas may be due to tectonic movements or human activities such as resource extraction. In difference, the uplift seen in other areas, where there is evidence of building up over time, might be influenced by both anthropogenic factors and natural tectonic processes. Moreover, our study highlights the intricate relationship between coastal dynamics, vertical land movements, and environmental changes. It highlights the critical need for integrated and multi-dimensional monitoring approaches to address these complex interactions. These results not only contribute to a deeper understanding of the Gizil-Aghaj State Reserve's coastal ecosystem but also offer valuable perspectives on the Caspian Sea's response to climate change. Such insights are crucial for developing adaptive strategies for coastal management and conservation in an era marked by environmental uncertainties and changes.
This paper studied the effects of Coulomb stress in understanding the proximity to failure on the... more This paper studied the effects of Coulomb stress in understanding the proximity to failure on the Palu-Koro fault system. An earthquake occurred on a large strike-slip fault in the northern part of Sulawesi Island, Indonesia, on September 28, 2018. Coulomb stress increased by approximately 1 bar, corresponding closely to the locations of aftershocks and areas where stress dropped by more than 10 bars. Based on the focal mechanisms of the aftershocks and source models of the main shock, the coulomb failure stress changes on both of the focal mechanism nodal planes are calculated. Additionally, we calculated the changes in Coulomb stress on the focal sources of each aftershock. Our stress model indicates a positive correlation within the areas of extended Coulomb stress caused by the combination of seismic activities. We investigated the Coulomb stress as a possible origin for the aftershocks, which are most likely to slip optimally oriented for failure due to the local stress field generated by the mainshock. The Palu 7.5 earthquake led to the distribution of surface displacements. Moreover, calculated horizontal displacement increased in the NW-SW direction, ranging from 1 to 1.3 meters. The stress maps included in this paper are crucial in predicting the expected locations of future aftershocks and mitigating the potential for earthquakes.
<p>In this research, the Interferometric Synthetic Aperture Radar (InSAR) method is... more <p>In this research, the Interferometric Synthetic Aperture Radar (InSAR) method is used to evaluate the connection between earthquakes and volcano dynamics in Azerbaijan. InSAR provides a robust technique for defining the complexity of earthquakes in spatial dimensions and provides more precise information about the effects of earthquakes than traditional methods. We assessed pre-, co-, and post-seismic scenarios to find the possible triggering relationships between moderate earthquakes and the Ayazakhtarma mud volcano. The Ayazakhtarma volcano is located 46 km from the 2021 Shamakhi and 67 km from the 2019 Basqal earthquakes, respectively. In this study, comprehensive deformation time series and velocities for the volcano using Sentinel 1A/B data between 2014 and 2022 were produced from LiCSAR products using LiCSBAS. At the same time, a radar line-of-sight (LOS) displacement map was generated based on results from the GMT5SAR for pre-, co-, and post-seismic deformation of earthquakes. Based on our observations of the following earthquakes, our results show that moderate earthquakes (Mw≤5) cannot trigger large mud volcano eruptions. In particular, the study of the Ayazakhtarma mud volcano revealed significant LOS changes that were positive and negative in the western half and eastern half of the site, respectively. Our research helps us comprehend how earthquakes impact eruptive processes. In two different situations, the interferograms enable the detection of ground displacement associated with mud volcano activity. At the Ayazakhtarma, faults also play a fairly important role in the deformation pattern. Interestingly, the observed fault system primarily exists in the region that divides sectors with various rates of subsidence. The interferometric data have been studied, providing new information on the deformation patterns of the Ayazakhtarma mud volcano.</p>
<p>To track global environmental change and evaluate the risk to sustainable develo... more <p>To track global environmental change and evaluate the risk to sustainable development, analysts and decision-makers in government, civil society, finance, and industry need the fundamental geospatial data products known as Land Use and Land Cover Change (LULCC) maps. Our research studied LULCC variations in a timeframe of 5 years in the Gabala district. Sentinel 2 open-source products were used to compare and categorize the procedure over one-year time intervals. For this investigation, the discrete indexing method was developed and used. The approach we used was focused on obtaining multiple indices and using them to improve classification performance. The Normalized Difference Vegetation Index (NDVI), Modified Normalized Difference Water Index (MNDWI), Bare Soil Index (BSI), Normalized Difference Tillage Index (NDTI), and Salinity Index (SI) are the indices evaluated. The most crucial variables were determined and classified using the random forest classifier in LULCC. The Sentinel Application Platform of the European Space Agency (SNAP ESA) algorithm was used to analyze the process and performed over 90% accurate predictions when applied to the testing dataset. Results revealed that using the RS technique, time and cost-efficient analyses are possible and reliable for developing socioeconomic and ecological growth strategies.</p>
The Eastern Mediterranean and Caucasus regions are two of the most seismically active deforming c... more The Eastern Mediterranean and Caucasus regions are two of the most seismically active deforming continental regions. Monitoring and studies of the extensive deformation processes in this comparatively limited region enhance our understanding of the continental collision in the region. In this paper, we built a new elastic block model to constrain present-day plate motions and regional deformation in the intraplate zone and estimate fault slip rates from a dense global positioning system (GPS) velocity field. We additionally considered differences in moment accumulation rate per unit fault length using seismogenic and geodetic depth along the main faults. The right-lateral slip rates were estimated at between 24.33 ± 0.47 and 28 ± 0.5 mm/year along the North Anatolian Fault Zone (NAFZ) and the left-lateral slip at 10.6 ± 0.9 to 12 ± 1 mm/year on the East Anatolian Fault Zone (EAFZ). The Dead Sea Transform Fault (DSTF) slip rate ranges between 4.1 ± 0.95 and 6 ± 1 mm/year. The slip rate for the Main Caucasus Thrust Fault (MCTF) is 6.5 ± 0.2 to 14.3 ± 0.7 mm/year from west to the east. A shallow locking depth of 9 ± 3.2 km was found in the Marmara region. The locking depth along the DSTF is 10.9 ± 5.5 km in the northern segment, 9 ± 6.7 km in the central section and 11.8 ± 4 km in the southern section. The locking depth of the EAFZ is 16.7 ± 4.4 km in the northern segment, 19.8 ± 7.4 km in the middle segment and 12.5 ± 4.2 km in the southern segment. The locking depths along the MCTF range between 12.7 ± 5.8 and 17.8 ± 4.9 km from west to east. Our new block model has the best fit to the observed velocities. The results provide an overall understanding of fault activity and have implications for the earthquake hazard along the main faults in the region.
In this study, a comprehensive statistical analysis was made for different parts of the world. Fo... more In this study, a comprehensive statistical analysis was made for different parts of the world. For this purpose, fundamental seismotectonic earthquake parameters such as b-value, magnitude completeness, Mc-value stress distribution and moment release were analysed and their interrelationship was investigated. In this context, for the evaluation of earthquake hazard potential, spatial variations of these fundamental parameters were achieved for the Eastern Mediterranean and Caucasus since there do not exist detailed studies including these parameters for these regions of the world. The high-resolution maps of the b-value, Mc-value and stress variance were analysed in the different seismotectonic regions in the Eastern Mediterranean and Caucasus. This study considers the spatial anomalies and correlation models between the b-value, faulting styles, and stress regime and moment release. Lower b-values (b ≤ 1) were observed along with the Main Marmara Fault, eastern Turkey, western Alborz, northern Zagros, south-east Iran and the north-east Caucasus, and these small b-values indicate the active seismic region. Mc level in most of Turkey is in and around 2.8. However, Mc-value is about 3.0 in the Caucasus and about 3.5 level in Iran.
This work also includes a stress inversion map in the region based on the focal mechanisms. The normal, strike-slip and a few thrust fault solutions were observed in the research areas. The results show that a combination of these parameters may supply preliminary tools for future researches. Consequently, the spatial pattern of the b-values, moment releases and stress regimes can be used as considerable promise for the predicting of forthcoming seismic hazard regions.
The Eastern Mediterranean and Caucasus regions are two of the most seismically active deforming c... more The Eastern Mediterranean and Caucasus regions are two of the most seismically active deforming continental regions. Monitoring and studies of the extensive deformation processes in this comparatively limited region enhance our understanding of the continental collision in the region. In this paper, we built a new elastic block model to constrain present-day plate motions and regional deformation in the intraplate zone and estimate fault slip rates from a dense global positioning system (GPS) velocity field. We additionally considered differences in moment accumulation rate per unit fault length using seismogenic and geodetic depth along the main faults. The right-lateral slip rates were estimated at between 24.33 ± 0.47 and 28 ± 0.5 mm/year along the North Anatolian Fault Zone (NAFZ) and the left-lateral slip at 10.6 ± 0.9 to 12 ± 1 mm/year on the East Anatolian Fault Zone (EAFZ). The Dead Sea Transform Fault (DSTF) slip rate ranges between 4.1 ± 0.95 and 6 ± 1 mm/year. The slip rate for the Main Caucasus Thrust Fault (MCTF) is 6.5 ± 0.2 to 14.3 ± 0.7 mm/year from west to the east. A shallow locking depth of 9 ± 3.2 km was found in the Marmara region. The locking depth along the DSTF is 10.9 ± 5.5 km in the northern segment, 9 ± 6.7 km in the central section and 11.8 ± 4 km in the southern section. The locking depth of the EAFZ is 16.7 ± 4.4 km in the northern segment, 19.8 ± 7.4 km in the middle segment and 12.5 ± 4.2 km in the southern segment. The locking depths along the MCTF range between 12.7 ± 5.8 and 17.8 ± 4.9 km from west to east. Our new block model has the best fit to the observed velocities. The results provide an overall understanding of fault activity and have implications for the earthquake hazard along the main faults in the region.
Physics of the Earth and Planetary Interiors , 2019
Coulomb stress variations may trigger earthquakes, while the stress transfer process is not clear... more Coulomb stress variations may trigger earthquakes, while the stress transfer process is not clear. In this paper, Coulomb stress changes are investigated for the sequences of strong earthquakes in the Caucasus region, which followed the 1988 M w 6.8 in Spitak, the 1991 M w 6.9 in Racha and the 2000 M w 6.2 in Baku. Our results show that the mainshocks induced variations in the stress field where most of the seismic events occurred. Coulomb stress increases 2 bars corresponding nearly to places of aftershocks, while the stress falls above 10 bars for Racha mainshock. The calculated Coulomb stress loaded about 5 bars at the end of rupture plane and the stress falls ~9 bars for Spitak mainshock. Our stress pattern shows a correlation within the areas of Coulomb stress caused by the combination of seismicity. Correlations between the coseismic Coulomb stress changes and the observed spatial patterns of the aftershocks created by the mainshock are illustrated by the stress variations over both optimally oriented and specified fault planes. An apparent correlation between the mainshock stress changes and the detected spatial pattern of the aftershocks is found, confirming the utility of the stress maps in constraining the expected locations of the forthcoming aftershocks and mitigating earthquake hazards.
The Eastern Mediterranean and Caucasus are located among the Eurasian, African and Arabian plates... more The Eastern Mediterranean and Caucasus are located among the Eurasian, African and Arabian plates, and tectonic activities are very complex. In this paper, the kinematics and strain distribution in these regions are determined and investigated from dense GPS observations with over 1000 stations and longer observations. The elastic block model is used to constrain present-day plate motions and crustal deformation. The relative Euler vectors between the Nubian, Arabian, Caucasus, Anatolian and Central Iranian plates are estimated. The Arabian-Eurasia, Anatolian-Eurasia, Nubian-Eurasia, Caucasus-Eurasia and Central Iranian Euler vectors are 0.584 ± 0.1 Myr À1 , 0.825 ± 0.064 Myr À1 , 0.35 ± 0.175 Myr À1 , 0.85 ± 0.086 Myr À1 and 0.126 ± 0.016 Myr À1. The strain rate in the East Mediterranean and Caucasus has been estimated from the GPS velocity field. The results show that the thrust dominated areas, the eastern Mediterranean-Middle East-Caucasus and Zagros have negative dilatation and the western Anatolia region has positive 2D dilatation rate with significant rotation. The west Anatolian shows the extension in NW-SE with about 150–199 nstrain/yr in the WE direction. The Central Anatolia shows compression rate below 50 nstrain/yr and extensional strain rate adjacent to East Anatolian Fault and Dead Sea Fault is about 0–100 nstrain/yr. The contraction strain rate is higher in Zagros and Caucasus between 100– 150 nstrain/yr and contraction orientation is along the NE-SW direction in Caucasus. The north part of Iran shows less contraction rate below 50 nstrain/yr but NorthEast Zagros Mountains, Tabriz fault and Chalderan fault show extensional rate between 50–110 nstrain/yr and principal axes rotation in the N-S direction. The maximum contraction observed in the Kopek Dag is about 100–194 nstrain/yr and orientated in the NE-SW direction. East Zagros Mountain and Makran subduction zone have a large clockwise rotation with 70–85 nradian and principal axes remains mostly along the N-S direction. The observed extension is along N-S by about 0–100 nstrain/yr with counter clockwise rotation in Dead Sea Fault. The Sinai block shows shortening rate in the range of 0–100 nstrain/yr.
In this study, ground response analysis on different 255 sites in Baku city of Azerbaijan was don... more In this study, ground response analysis on different 255 sites in Baku city of Azerbaijan was done. The damage distribution is estimated on the basis of local site effects. Aiming to estimate local site effect, analysis of the ratio of horizontal to vertical (H/V) spectra of microtremor records was performed. The records are conducted with the Guralp CMG-5TD accelerometer and, with the Nakamura's approach, dynamic characteristics of surface ground are estimated. The maps showing the distribution of the amplification and resonance frequency for the grounds of Baku city were produced, which demonstrate variability and heterogeneity of ground characteristics in the city. The results can be used for urban seismic hazard assessment researches in the future.
The decreasing sea level of the Caspian Sea is having a serious impact on coastal ecosystems and ... more The decreasing sea level of the Caspian Sea is having a serious impact on coastal ecosystems and biodiversity. This study, conducted over a decade from 2014 to 2023, provides a comprehensive analysis of the coastal transformations in the Gizil-Aghaj State Reserve, Azerbaijan, using remote sensing technologies. By utilizing a combination of optical and radar satellite data, we mapped the evolving interplay between land and sea. Our research reveals a significant coastline shift, with the Caspian Sea receding to expose an additional 218 km2 of land. This significant change was most apparent in the northeastern area, corresponding with regions experiencing substantial land subsidence. As the Caspian Sea's level decreases and the land sinks simultaneously, it's reasonable to expect that the shoreline would remain stable. In contrast to areas with land subsidence, places where the land is uplifting, along with the Caspian Sea's decreasing level, are likely to experience noticeable changes in their shoreline, suggesting a more dynamic and changing coastal area. These findings are crucial for understanding the fluctuations in the Caspian Sea level, likely influenced by a combination of natural geological processes, human activities, and broader climatic trends. The subsidence observed in some areas may be due to tectonic movements or human activities such as resource extraction. In difference, the uplift seen in other areas, where there is evidence of building up over time, might be influenced by both anthropogenic factors and natural tectonic processes. Moreover, our study highlights the intricate relationship between coastal dynamics, vertical land movements, and environmental changes. It highlights the critical need for integrated and multi-dimensional monitoring approaches to address these complex interactions. These results not only contribute to a deeper understanding of the Gizil-Aghaj State Reserve's coastal ecosystem but also offer valuable perspectives on the Caspian Sea's response to climate change. Such insights are crucial for developing adaptive strategies for coastal management and conservation in an era marked by environmental uncertainties and changes.
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Papers by Bahruz Ahadov
This work also includes a stress inversion map in the region based on the focal mechanisms. The normal, strike-slip and a few thrust fault solutions were observed in the research areas. The results show that a combination of these parameters may supply preliminary tools for future researches. Consequently, the spatial pattern of the b-values, moment releases and stress regimes can be used as considerable promise for the predicting of forthcoming seismic hazard regions.
Conference Presentations by Bahruz Ahadov
address these complex interactions. These results not only contribute to a deeper understanding of the Gizil-Aghaj State Reserve's coastal ecosystem but also offer valuable perspectives on the Caspian Sea's response to climate change. Such insights are crucial for developing adaptive strategies for coastal management and conservation in an era marked by environmental uncertainties and changes.
This work also includes a stress inversion map in the region based on the focal mechanisms. The normal, strike-slip and a few thrust fault solutions were observed in the research areas. The results show that a combination of these parameters may supply preliminary tools for future researches. Consequently, the spatial pattern of the b-values, moment releases and stress regimes can be used as considerable promise for the predicting of forthcoming seismic hazard regions.
address these complex interactions. These results not only contribute to a deeper understanding of the Gizil-Aghaj State Reserve's coastal ecosystem but also offer valuable perspectives on the Caspian Sea's response to climate change. Such insights are crucial for developing adaptive strategies for coastal management and conservation in an era marked by environmental uncertainties and changes.