Pub Date : 2021-01-09DOI: 10.30495/IJES.2021.678953
Raghucharan Choudari Manikya, S. Somala, O. Erteleva, R. Evgenii
Seismic hazard for the central indo-gangetic plains (CIGP) is either available in terms of generalized hazard spectrum as per IS 1893:2016 or in terms of only Peak Ground Acceleration (PGA) at the city level. Also, the study region falls in the seismic gap region, which has a potential for an earthquake of Mw>8.0. Hence, in this study, the seismic risk is assessed for the first time at the district level in the seismically critical region of India, the CIGP. In addition, the relative contribution of parametric and model uncertainties is also quantified from sensitivity analysis. Seismic risk results reveal that mud mortar bricks with temporary roofing (MMB) have the highest collapse probability of ~0.6. Further, brick walls with stone roof (BSR) and brick walls with metal sheet roof (BMS) also have high extensive and collapse damage compared to other building groups. These building types need immediate retrofitting / replacement for effective disaster mitigation. Also, geo-unit Allahabad, even though lying in zone II as per IS 1893:2016, has the most number of homeless and uninhabitable dwellings. Further, for a future earthquake of magnitude in the range of Mw 7.5 and 8.5, the expected financial loss might vary from 60 to 150 billion dollars, and the human loss might vary between 0.8 and 2.8 lakhs, respectively. Finally, results from this study will create awareness in the general public, policymakers, and structural engineers for taking up necessary mitigation measures on the existing buildings of CIGP for better preparedness from a future strong earthquake.
{"title":"Seismic risk assessment for central Indo-Gangetic Plains, India","authors":"Raghucharan Choudari Manikya, S. Somala, O. Erteleva, R. Evgenii","doi":"10.30495/IJES.2021.678953","DOIUrl":"https://doi.org/10.30495/IJES.2021.678953","url":null,"abstract":"Seismic hazard for the central indo-gangetic plains (CIGP) is either available in terms of generalized hazard spectrum as per IS 1893:2016 or in terms of only Peak Ground Acceleration (PGA) at the city level. Also, the study region falls in the seismic gap region, which has a potential for an earthquake of Mw>8.0. Hence, in this study, the seismic risk is assessed for the first time at the district level in the seismically critical region of India, the CIGP. In addition, the relative contribution of parametric and model uncertainties is also quantified from sensitivity analysis. Seismic risk results reveal that mud mortar bricks with temporary roofing (MMB) have the highest collapse probability of ~0.6. Further, brick walls with stone roof (BSR) and brick walls with metal sheet roof (BMS) also have high extensive and collapse damage compared to other building groups. These building types need immediate retrofitting / replacement for effective disaster mitigation. Also, geo-unit Allahabad, even though lying in zone II as per IS 1893:2016, has the most number of homeless and uninhabitable dwellings. Further, for a future earthquake of magnitude in the range of Mw 7.5 and 8.5, the expected financial loss might vary from 60 to 150 billion dollars, and the human loss might vary between 0.8 and 2.8 lakhs, respectively. Finally, results from this study will create awareness in the general public, policymakers, and structural engineers for taking up necessary mitigation measures on the existing buildings of CIGP for better preparedness from a future strong earthquake.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47575268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.30495/IJES.2021.678952
Sahar Ahmad, Z. Rehman, Suleman Khan, B. Wadood, Mati Ul Haq, Shuhab D. Khan, Yasir Khan, H. Khan, Shehla Gul
Four belemnite genera and twelve age-diagnostic species were identified from the from Upper Jurassic–Lower Cretaceous sequence of the Chichali Formation, northwest Pakistan. Four local biozones were established based on the identified belemnites. These biozones are arranged from base to top as follows; Hibolithes pilleti/Hibolithes jaculoides/Hibolithes hastatus Zone of Kimmeridgian age, Hibolithes marwicki marwicki/Hibolithes arkelli Zone of Tithonian age, Belemnopsis malucana Zone defines Tithonian–Berriasian boundary, and Neohibolites ewaldi/Hibolithes longior/Belemnopsis jonkeri Zone of Velanginian age. The biostratigraphic and paleogeographic occurrences of belemnites in the Tethyan and Boreal Realms were used to identify the migration pathways and distinctive paleobiogeographic provinces of belemnites. The paleoceanic settings closely linked the Upper Jurassic strata (~Biozones 1–2, representing the Kimmeridgian–Tithonian range) in the Tethyan and the Boreal Realms. The Lower Cretaceous (~Biozone 3, representing the Berriasian) strata also reveal a persistent oceanic connection between the Indo-Pacific and Mediterranean Provinces. However, the Boreal and Tethyan Realms were also connected in the Lower Cretaceous (~Biozone 4, representing the Velanginian strata) by shallow-water routes.
{"title":"Belemnite biostratigraphy of the upper Jurassic to lower Cretaceous strata in the Surghar range, NW Pakistan: Systematic and Paleobiogeographic implications","authors":"Sahar Ahmad, Z. Rehman, Suleman Khan, B. Wadood, Mati Ul Haq, Shuhab D. Khan, Yasir Khan, H. Khan, Shehla Gul","doi":"10.30495/IJES.2021.678952","DOIUrl":"https://doi.org/10.30495/IJES.2021.678952","url":null,"abstract":"Four belemnite genera and twelve age-diagnostic species were identified from the from Upper Jurassic–Lower Cretaceous sequence of the Chichali Formation, northwest Pakistan. Four local biozones were established based on the identified belemnites. These biozones are arranged from base to top as follows; Hibolithes pilleti/Hibolithes jaculoides/Hibolithes hastatus Zone of Kimmeridgian age, Hibolithes marwicki marwicki/Hibolithes arkelli Zone of Tithonian age, Belemnopsis malucana Zone defines Tithonian–Berriasian boundary, and Neohibolites ewaldi/Hibolithes longior/Belemnopsis jonkeri Zone of Velanginian age. The biostratigraphic and paleogeographic occurrences of belemnites in the Tethyan and Boreal Realms were used to identify the migration pathways and distinctive paleobiogeographic provinces of belemnites. The paleoceanic settings closely linked the Upper Jurassic strata (~Biozones 1–2, representing the Kimmeridgian–Tithonian range) in the Tethyan and the Boreal Realms. The Lower Cretaceous (~Biozone 3, representing the Berriasian) strata also reveal a persistent oceanic connection between the Indo-Pacific and Mediterranean Provinces. However, the Boreal and Tethyan Realms were also connected in the Lower Cretaceous (~Biozone 4, representing the Velanginian strata) by shallow-water routes.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70077444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.30495/IJES.2021.677471
K. V. Nagesha, Harinandan Kumar, Muralidhar Munisingh
The mining process generates significant amount of dust in the form of particulate matters into the atmosphere. Out of different mining process, opencast mining produces more dust than that of underground mining because of exposure in the ambiance. The mining operations are directly or indirectly involved in the production of dust particles. The activities like drilling operation, Blasting and haul road operations produce fugitive dust and causes significant deterioration of mine atmosphere. This fugitive dust consists of particulate matters (PM), which are more harmful to the human respiratory system. The prevention measures is only possible when the actual prediction of emission of those fugitive dust particles are possible. There is several model that predict the emission of the dust particles, but there is very less model to predict fugitive dust produced from a drilling operation in surface mines. In this paper, study was carried out to develop dust prediction model and to assess the influence of rock properties on dust emission. Based on the results obtained the developed model exhibit close proximity of predicted as well as field measured values with a regression coefficient of 0.75. Thus, the development of the model with effective prediction capability is the novelty of this paper. Decrease in dust emission rate was observed with increased moisture content present in drill cuttings, higher compressive strength, and density.
{"title":"Influence of rock properties on emission rate of Particulates Matter (Pm) during drilling operation in surface mines","authors":"K. V. Nagesha, Harinandan Kumar, Muralidhar Munisingh","doi":"10.30495/IJES.2021.677471","DOIUrl":"https://doi.org/10.30495/IJES.2021.677471","url":null,"abstract":"The mining process generates significant amount of dust in the form of particulate matters into the atmosphere. Out of different mining process, opencast mining produces more dust than that of underground mining because of exposure in the ambiance. The mining operations are directly or indirectly involved in the production of dust particles. The activities like drilling operation, Blasting and haul road operations produce fugitive dust and causes significant deterioration of mine atmosphere. This fugitive dust consists of particulate matters (PM), which are more harmful to the human respiratory system. The prevention measures is only possible when the actual prediction of emission of those fugitive dust particles are possible. There is several model that predict the emission of the dust particles, but there is very less model to predict fugitive dust produced from a drilling operation in surface mines. In this paper, study was carried out to develop dust prediction model and to assess the influence of rock properties on dust emission. Based on the results obtained the developed model exhibit close proximity of predicted as well as field measured values with a regression coefficient of 0.75. Thus, the development of the model with effective prediction capability is the novelty of this paper. Decrease in dust emission rate was observed with increased moisture content present in drill cuttings, higher compressive strength, and density.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70076565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.30495/IJES.2021.678955
S. Mohammadi, B. Rezai, AliAkbar Abdollazadeh, Sayed Mojtaba Mortazavi
Geometallurgy has become an important tool to predict the processing behaviour of ores, and to decrease the production risks associated with the variable nature of economic mineral deposits. Understanding the ore variability and subsequently the response of the ore to processing are considered to be the most important functions of an accurate geometallurgical study. In this paper geometallurgical indices for grinding properties of a copper ore are investigated. Geometallurgical index (GI) is described as any geological feature which makes a footprint on the processing performance of the ores. A comprehensive study at Sarcheshmeh porphyry copper mine was undertaken. This included the process responses of the ore such as grade, recovery and plant throughput as possible geometallurgical indices. In this paper the effects of rock breakage variability on the plant throughput and energy consumption are presented. Ninety samples were collected based on geological features including lithology, hydrothermal alteration, and geological structures. The samples were characterized using X-ray diffraction, X-ray fluorescence, electron and optical microscopy. A small scale simulated test method for Bond ball mill work index (BWI) was used to perform the comminution examinations. The results showed that BWI values vary from 5.67 kWh/t to 20.21 kWh/t. Examination of the possible correlations between BWI and the geological features showed that the key geological feature related to comminution variability is lithology. In addition, the hydrothermal alteration would be an effective parameter in the period that the plant is fed with a single lithology.
{"title":"Evaluation of the geometallurgical indices for comminution properties at Sarcheshmeh porphyry copper mine, Iran","authors":"S. Mohammadi, B. Rezai, AliAkbar Abdollazadeh, Sayed Mojtaba Mortazavi","doi":"10.30495/IJES.2021.678955","DOIUrl":"https://doi.org/10.30495/IJES.2021.678955","url":null,"abstract":"Geometallurgy has become an important tool to predict the processing behaviour of ores, and to decrease the production risks associated with the variable nature of economic mineral deposits. Understanding the ore variability and subsequently the response of the ore to processing are considered to be the most important functions of an accurate geometallurgical study. In this paper geometallurgical indices for grinding properties of a copper ore are investigated. Geometallurgical index (GI) is described as any geological feature which makes a footprint on the processing performance of the ores. A comprehensive study at Sarcheshmeh porphyry copper mine was undertaken. This included the process responses of the ore such as grade, recovery and plant throughput as possible geometallurgical indices. In this paper the effects of rock breakage variability on the plant throughput and energy consumption are presented. Ninety samples were collected based on geological features including lithology, hydrothermal alteration, and geological structures. The samples were characterized using X-ray diffraction, X-ray fluorescence, electron and optical microscopy. A small scale simulated test method for Bond ball mill work index (BWI) was used to perform the comminution examinations. The results showed that BWI values vary from 5.67 kWh/t to 20.21 kWh/t. Examination of the possible correlations between BWI and the geological features showed that the key geological feature related to comminution variability is lithology. In addition, the hydrothermal alteration would be an effective parameter in the period that the plant is fed with a single lithology.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70077452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.30495/IJES.2021.678956
H. Sadeghi, B. Rahimi, P. Babaei
A total of 324 strong ground-motion records from 26 earthquakes with moment magnitude greater than 6 were used to derive an adequate equation for moment magnitude estimation. A parameter called total effective shaking was used to introduce an empirical equation for determining the near real-time magnitude of the Iranian plateau. This parameter was obtained through time integration of the absolute acceleration values from accelerograms over the strong shaking duration. It can be calculated by a simple mathematical procedure 5 seconds after completion of the waveform by decreasing the amplitudes to less than 20% of the maximum ground acceleration. The total effective shaking has a dimension of velocity and corresponds to moment magnitude and hypocentral distance in an attenuation relationship. The optimum coefficients were calculated through least-square regression analysis. Also, the effect of site conditions was evaluated in the analysis. The average shear-wave velocity to a depth of 30 m beneath each recording station was taken into account as the local site effect for 147 records out of the total number of records. The estimated moment magnitudes are in reasonably good agreement with the Global CMT values. Their differences are mostly less than 0.25 in the magnitude unit.
{"title":"Rapid moment magnitude estimation for large earthquakes in Iran using time integration of absolute ground accelerations","authors":"H. Sadeghi, B. Rahimi, P. Babaei","doi":"10.30495/IJES.2021.678956","DOIUrl":"https://doi.org/10.30495/IJES.2021.678956","url":null,"abstract":"A total of 324 strong ground-motion records from 26 earthquakes with moment magnitude greater than 6 were used to derive an adequate equation for moment magnitude estimation. A parameter called total effective shaking was used to introduce an empirical equation for determining the near real-time magnitude of the Iranian plateau. This parameter was obtained through time integration of the absolute acceleration values from accelerograms over the strong shaking duration. It can be calculated by a simple mathematical procedure 5 seconds after completion of the waveform by decreasing the amplitudes to less than 20% of the maximum ground acceleration. The total effective shaking has a dimension of velocity and corresponds to moment magnitude and hypocentral distance in an attenuation relationship. The optimum coefficients were calculated through least-square regression analysis. Also, the effect of site conditions was evaluated in the analysis. The average shear-wave velocity to a depth of 30 m beneath each recording station was taken into account as the local site effect for 147 records out of the total number of records. The estimated moment magnitudes are in reasonably good agreement with the Global CMT values. Their differences are mostly less than 0.25 in the magnitude unit.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70077464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.30495/IJES.2021.680583
B. Sadeghi
In geochemical anomaly classification, different mathematical-statistical models have been applied. The final classified map provides only one scenario. This model is not certain enough since every model provides several thresholds which are almost different from each other meaning dissimilarity and spatial uncertainty of the classified maps. Spatial uncertainty of the models could be quantified considering the difference between the associated geochemical scenarios simulated (called: ‘realizations’) by geostatistical simulation (GS) methods. However, the main problem with GS methods is that these methods are significantly time-consuming, and CPU- and memory-demanding. To improve such problems, in this research, the method of “scaling and projecting sample-locations (SPS)” is developed. Based on the SPS theory, first of all, the whole sample-locations were projected (centralized) and scaled into a box coordinated between (0,0) to (150,0) and (0,0) to (0,100), for example (they can be equal though), with the cell-size of 1 m2. Therefore, the time consumed and the memory demanded to generate a large number of realizations, for example, 1000 realizations based on the non-scaled/non-projected (NS/NP) and scaled/projected (S/P) sample locations per case-study were quantified. In this study, the turning bands simulation (TBSIM) were applied to geochemical datasets of three different case studies to take the area scales, regularity/irregularity and density of the samples into account. The comparison between NS/NP and S/P results statistically demonstrated the same results, however, the process and outputs of the S/P samples took a significantly shorter time and consumed a remarkably lower computer-memory. Therefore, experts are able to easily run this algorithm using any normal computer.
{"title":"SPS Model: a significant algorithm to reduce the time and computer memory required in geostatistical simulations","authors":"B. Sadeghi","doi":"10.30495/IJES.2021.680583","DOIUrl":"https://doi.org/10.30495/IJES.2021.680583","url":null,"abstract":"In geochemical anomaly classification, different mathematical-statistical models have been applied. The final classified map provides only one scenario. This model is not certain enough since every model provides several thresholds which are almost different from each other meaning dissimilarity and spatial uncertainty of the classified maps. Spatial uncertainty of the models could be quantified considering the difference between the associated geochemical scenarios simulated (called: ‘realizations’) by geostatistical simulation (GS) methods. However, the main problem with GS methods is that these methods are significantly time-consuming, and CPU- and memory-demanding. To improve such problems, in this research, the method of “scaling and projecting sample-locations (SPS)” is developed. Based on the SPS theory, first of all, the whole sample-locations were projected (centralized) and scaled into a box coordinated between (0,0) to (150,0) and (0,0) to (0,100), for example (they can be equal though), with the cell-size of 1 m2. Therefore, the time consumed and the memory demanded to generate a large number of realizations, for example, 1000 realizations based on the non-scaled/non-projected (NS/NP) and scaled/projected (S/P) sample locations per case-study were quantified. In this study, the turning bands simulation (TBSIM) were applied to geochemical datasets of three different case studies to take the area scales, regularity/irregularity and density of the samples into account. The comparison between NS/NP and S/P results statistically demonstrated the same results, however, the process and outputs of the S/P samples took a significantly shorter time and consumed a remarkably lower computer-memory. Therefore, experts are able to easily run this algorithm using any normal computer.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70077016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-01DOI: 10.30495/IJES.2020.677468
Leila Khodaei Geshlag, S. Roostaei, D. Mokhtari, K. Valizadeh
The 2012 Ahar-Varzegan earthquake and its aftershocks have not only caused huge damage with a severe loss of life and property but also induced many geo-hazards with the major type of collapse, creep, slip, debris flow, and fallings that are generally considered as landslide in this study which can cause continuous threats to the affected region. in this study, a semi-automated geo-hazard detection method has been presented to determine the Landslides due to 2012 Ahar-Varzaghan earthquake in area from Ahar to Varzaghan by the use of bi- temporal Landsat images from before and after the earthquake. The accuracy of the results was checked out using field observations, Google Earth images and the error matrix. The results of the visual validation with the Google Earth images showed that the used method can detect landslids with relatively high accuracy.The images of landsat5 and 8 Because of their multispectral advantages can be used as a suitable data source for research on Instabilities. Finally, the validating results obtained by using the error matrix showed the total accuracy of 92.1% and kappa coefficient was 0.99. So based on the results obtained from the above method, the landslides were distributed mainly in slopes between 15 and 40 degrees and the height distribution of instabilities of 1420 to 2000 meters. Also based on vegetation indices, density of landslides have been increased after the earthquake. Generally unstabel slopes are located along river valleys and roads in mountain regions with deep valleys and steep slopes. According to the nature of present study, the obtained result can be useful for environmental planners and project developers.
{"title":"Application of landsat imageries for mapping post-earthquake landslide, case study: 2012 Ahar-Varzegan earthquake, NW Iran","authors":"Leila Khodaei Geshlag, S. Roostaei, D. Mokhtari, K. Valizadeh","doi":"10.30495/IJES.2020.677468","DOIUrl":"https://doi.org/10.30495/IJES.2020.677468","url":null,"abstract":"The 2012 Ahar-Varzegan earthquake and its aftershocks have not only caused huge damage with a severe loss of life and property but also induced many geo-hazards with the major type of collapse, creep, slip, debris flow, and fallings that are generally considered as landslide in this study which can cause continuous threats to the affected region. in this study, a semi-automated geo-hazard detection method has been presented to determine the Landslides due to 2012 Ahar-Varzaghan earthquake in area from Ahar to Varzaghan by the use of bi- temporal Landsat images from before and after the earthquake. The accuracy of the results was checked out using field observations, Google Earth images and the error matrix. The results of the visual validation with the Google Earth images showed that the used method can detect landslids with relatively high accuracy.The images of landsat5 and 8 Because of their multispectral advantages can be used as a suitable data source for research on Instabilities. Finally, the validating results obtained by using the error matrix showed the total accuracy of 92.1% and kappa coefficient was 0.99. So based on the results obtained from the above method, the landslides were distributed mainly in slopes between 15 and 40 degrees and the height distribution of instabilities of 1420 to 2000 meters. Also based on vegetation indices, density of landslides have been increased after the earthquake. Generally unstabel slopes are located along river valleys and roads in mountain regions with deep valleys and steep slopes. According to the nature of present study, the obtained result can be useful for environmental planners and project developers.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41861945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-01DOI: 10.30495/IJES.2020.677472
Narayanakumar Somasundaram, S. Somala, E. Rogozhin, S. Rodina
This paper study the recent seismicity in Earthquake hazard zones in India. A large historical earthquake event catalog to cover the period of 1900-2018, the parameters date, time, latitude, longitude, depth and magnitude has been used to calculating frequency-magnitude distribution (b-value) of seismic hazard zones in India. To convert different magnitude scales into a single moment magnitude scale, the general orthogonal regression relation is used. Gamma distribution used for variable corrections also de-clustering method has used for removal of any non-Poisson distribution. The Indian seismic hazard zones are divided into five major seismic sources zones. The seismicity is characterized by Gutenberg-Richter relation. The parameter ‘b’ of FMD and relationship have been determined for these five seismic zones having different vulnerability environment. The ‘b’ values ranges between 0.43 to 1.16. The difference between the b parameters and seismic hazard level from seismic zones II to V considered for the study of high seismo-tectonic complexity and crustal heterogeneity, the parameter ‘a’ value changes accordingly the seismicity of the regions. The lowest b-values found in seismic zone II. The highest FMD b-value has been found in the seismic zone IV. Such high seismicity b-values may be associated with high heterogeneity. In this high b-value predict the low strength in the crust as well as seismic instabilities of that zone. These observations recommend not suggesting the location of important projects like atomic power stations, hydroelectric power stations, neutrino observatory projects, satellite town projects.
{"title":"Seismic study and spatial observations of a & b – values for the different earthquake hazard zones of India","authors":"Narayanakumar Somasundaram, S. Somala, E. Rogozhin, S. Rodina","doi":"10.30495/IJES.2020.677472","DOIUrl":"https://doi.org/10.30495/IJES.2020.677472","url":null,"abstract":"This paper study the recent seismicity in Earthquake hazard zones in India. A large historical earthquake event catalog to cover the period of 1900-2018, the parameters date, time, latitude, longitude, depth and magnitude has been used to calculating frequency-magnitude distribution (b-value) of seismic hazard zones in India. To convert different magnitude scales into a single moment magnitude scale, the general orthogonal regression relation is used. Gamma distribution used for variable corrections also de-clustering method has used for removal of any non-Poisson distribution. The Indian seismic hazard zones are divided into five major seismic sources zones. The seismicity is characterized by Gutenberg-Richter relation. The parameter ‘b’ of FMD and relationship have been determined for these five seismic zones having different vulnerability environment. The ‘b’ values ranges between 0.43 to 1.16. The difference between the b parameters and seismic hazard level from seismic zones II to V considered for the study of high seismo-tectonic complexity and crustal heterogeneity, the parameter ‘a’ value changes accordingly the seismicity of the regions. The lowest b-values found in seismic zone II. The highest FMD b-value has been found in the seismic zone IV. Such high seismicity b-values may be associated with high heterogeneity. In this high b-value predict the low strength in the crust as well as seismic instabilities of that zone. These observations recommend not suggesting the location of important projects like atomic power stations, hydroelectric power stations, neutrino observatory projects, satellite town projects.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48051969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-01DOI: 10.30495/IJES.2020.677473
Rizki Satria Rachman, Winantris Winantris, B. Muljana
Floral diversity is a measure of number of type flora in an area, and reflects how vegetation develops in response to the environmental condition during a certain time interval. The present study aims to examine changes in the diversity of vegetation (pollen, spores and algae), evenness, and similarity in the Bandung Basin through a core of 240 cm depth using a ground drill, as well as the radiocarbon dating (940 ± 120 BP) of a clayey peat level, located at the bottom (172.5 - 52.5 cm depth) of study section. Twenty four samples were taken at 5 cm intervals down the surface of the sediment core. Changes were obtained by comparing the quantity of pollen, spores, algae, and the lithology of the deposits. Palynomorph data show that Shannon diversity index ranged from 2.14 to 2.80 for pollen and spores, and 0 to 1.64 for algae; Shannon evenness index ranged from 0.64 to 0.81 for pollen and spores, and 0 to 1.74 for algae; and Jaccard similarity index results ranged from 30% - 68%. Faunal diversity is moderate with a good level of balance, and an overall trend in the increase of diversity in the clayey peat level. These changes are influenced by the presence of the Lembang Fault.
{"title":"A history of Floral diversity (pollen, spores and algal) during the latest Holocene in the Bandung basin based on palynological analysis in Cihideung, West Java, Indonesia","authors":"Rizki Satria Rachman, Winantris Winantris, B. Muljana","doi":"10.30495/IJES.2020.677473","DOIUrl":"https://doi.org/10.30495/IJES.2020.677473","url":null,"abstract":"Floral diversity is a measure of number of type flora in an area, and reflects how vegetation develops in response to the environmental condition during a certain time interval. The present study aims to examine changes in the diversity of vegetation (pollen, spores and algae), evenness, and similarity in the Bandung Basin through a core of 240 cm depth using a ground drill, as well as the radiocarbon dating (940 ± 120 BP) of a clayey peat level, located at the bottom (172.5 - 52.5 cm depth) of study section. Twenty four samples were taken at 5 cm intervals down the surface of the sediment core. Changes were obtained by comparing the quantity of pollen, spores, algae, and the lithology of the deposits. Palynomorph data show that Shannon diversity index ranged from 2.14 to 2.80 for pollen and spores, and 0 to 1.64 for algae; Shannon evenness index ranged from 0.64 to 0.81 for pollen and spores, and 0 to 1.74 for algae; and Jaccard similarity index results ranged from 30% - 68%. Faunal diversity is moderate with a good level of balance, and an overall trend in the increase of diversity in the clayey peat level. These changes are influenced by the presence of the Lembang Fault.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47019187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-01DOI: 10.30495/IJES.2020.677470
Pouya Sadeghi-Farshbaf, M. Khatib, H. Nazari
Detection of fault segments is an essential step for tracking main transverse faults. General observations from field studies as well as attitude measurements can give an overall understanding of the lengths of the segments, but these are not always sufficient to accurately identify and characterize them. In this study, we analyze P–T dihedra variations based on their eigenvalues to detect fault segments. The anomalies of local paleostress distribution aid us to detect the segment boundaries. This study focuses on the Northwestern, Central, and Southeastern sectors of the North Tabriz Fault (NTF). Fault azimuth distribution and eigenvalue anomalies as well as the fault attitudes for each interval distance have been used to distinct segment boundaries. The results are verified by checking the presence of the transverse faults at the proposed sites during fieldwork. Results show a new structural arrangement integrated by the already documented NTF segments, combined with 6 related transverse faults. In this way, we confirm the earlier reported segments, and we improve the NFT characterization by introducing new segments bounded by transverse faults.
{"title":"Detection of fault segments based on P–T dihedra analysis along the North Tabriz fault, NW Iran","authors":"Pouya Sadeghi-Farshbaf, M. Khatib, H. Nazari","doi":"10.30495/IJES.2020.677470","DOIUrl":"https://doi.org/10.30495/IJES.2020.677470","url":null,"abstract":"Detection of fault segments is an essential step for tracking main transverse faults. General observations from field studies as well as attitude measurements can give an overall understanding of the lengths of the segments, but these are not always sufficient to accurately identify and characterize them. In this study, we analyze P–T dihedra variations based on their eigenvalues to detect fault segments. The anomalies of local paleostress distribution aid us to detect the segment boundaries. This study focuses on the Northwestern, Central, and Southeastern sectors of the North Tabriz Fault (NTF). Fault azimuth distribution and eigenvalue anomalies as well as the fault attitudes for each interval distance have been used to distinct segment boundaries. The results are verified by checking the presence of the transverse faults at the proposed sites during fieldwork. Results show a new structural arrangement integrated by the already documented NTF segments, combined with 6 related transverse faults. In this way, we confirm the earlier reported segments, and we improve the NFT characterization by introducing new segments bounded by transverse faults.","PeriodicalId":44351,"journal":{"name":"Iranian Journal of Earth Sciences","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44585825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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