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Physical Properties of the Earth Crust Within the Joint Zone Between Turan Platform and Orogenic Structures of Tien-Shan
Dilshot Atabaev,
Oleg Mordvintsev,
Dmitriy Mordvintsev,
Nasiba Atabaeva
Issue:
Volume 8, Issue 2, April 2019
Pages:
69-80
Received:
22 January 2019
Accepted:
2 March 2019
Published:
20 March 2019
Abstract: The main aim of the study, presented in this article was to precise the deep geological structure of joint zone between the Tien-Shan orogenics and Turan platform. Within this research we have determined the petrophysical features of the pre-Mesozoic sections of this zone. These data will help us in the further prospecting works for minerals searching. The principal method of study was the seismic-density modelling data complex interpretation, bonded to the geological and subsurface information from the previous works. The modeling was provided along the lines in the South-Western Gissar region, Uzbekistan. The main features, we paid attention, were rocks density, seismic wave velocity and magnetic features. As a result, deep geological structure and petrophysical features of different pre-Mesozoic formations of the study area were obtained.
Abstract: The main aim of the study, presented in this article was to precise the deep geological structure of joint zone between the Tien-Shan orogenics and Turan platform. Within this research we have determined the petrophysical features of the pre-Mesozoic sections of this zone. These data will help us in the further prospecting works for minerals search...
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Estimation of Seismic Ground Motions and Attendant Potential Human Fatalities from Scenario Earthquakes on the Sanchiao Fault in Taipei City, Taiwan
Issue:
Volume 8, Issue 2, April 2019
Pages:
81-93
Received:
12 February 2019
Accepted:
14 March 2019
Published:
3 April 2019
Abstract: The purpose of this study is to estimate maximum ground motions in Taipei city in the form of ShakeMaps as well as to assess potential human fatalities from scenario earthquakes on the Sanchiao active faults in this area. Analysis of seismic hazard potential becomes necessary in Taipei City for the Central Geological Survey (CGS) announced the Sanchiao active fault as Category II. The resultant ShakeMap patterns of maximum ground motion by using ground motion prediction equation (GMPE) method in a case of Mw6.88 show the areas of PGA above 400 gals are located in the northern and western parts of Taipei. Furthermore, the areas of PGA above 500 gals are located in these regions: Beitou, Shihlin, Datong, Wanhua, Jhongjheng, northern Neihu, western Jhongshan, western Daan and western Sinyi. In addition, seismic hazards in terms of PGA and PGV in the vicinity of the Sanchiao fault are not completely dominated by the Sanchiao fault. The main reason is that some areas located in the vicinity of the Sanchiao fault are marked with low site response amplification values of 0.55 and 0.67 for PGA and PGV, respectively. Finally, from estimation of potential human fatalities from scenario earthquakes on the Sanchiao active fault, it is noted that potential fatalities increase rapidly in people above age 45. Total fatalities reach a high peak in age groups of 55–64. Another to pay special attention is Taipei City has hundreds of thousands of households whose residences over 40 years old. When a strong earthquake strikes, these old houses are vulnerable to collapse. In light of the results of this study, the author urge both the municipal and central governments to take effective seismic hazard mitigation measures in the highly urbanized areas with a large number of old buildings in Taipei city. The results of this study will show which areas with higher earthquake hazard potential in Taipei City. It will help mitigate Taipei City earthquake disaster loss in the future, as well as provide critical information for emergency response plans.
Abstract: The purpose of this study is to estimate maximum ground motions in Taipei city in the form of ShakeMaps as well as to assess potential human fatalities from scenario earthquakes on the Sanchiao active faults in this area. Analysis of seismic hazard potential becomes necessary in Taipei City for the Central Geological Survey (CGS) announced the Sanc...
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Terrestrial Plagioclase Olivine Clinopyroxenite as a Possible Analogue of Lunar Rocks
Victor Grigorievich Korinevsky,
Eugeny Victorovich Korinevsky
Issue:
Volume 8, Issue 2, April 2019
Pages:
94-101
Received:
10 December 2018
Accepted:
19 March 2019
Published:
29 April 2019
Abstract: The article describes the mineral composition and petrochemistry of a unique ancient (more than 1848–2011 MA) igneous rock of the Urals – plagioclase olivine clinopyroxenite. These rocks are considered the oldest in the Urals. In the literature they are described under the name izrandites. They are part of the foundation of the basement of the East European platform. These rocks are highly aluminous and calcic. They are characterized by a low amount of alkalis and magnesium oxide and a comparable amount of silicon and iron. A certain petrochemical similarity is found between the izrandites and the anorthite leucogabbro, troctolite, and noritic anorthosites of lunar highlands. This similarity enhances the closeness of distribution of the minor elements, the leading role among which belongs to Sr and Ba. In those and others rocks plagioclase is represented by anorthite or labrador, its amount makes up from 5–8 to 50–70%. The izrandites are representatives of the rocks of the lower part of the Earth's crust, which in composition and absolute age can be compared with the youngest leucogabbros and troctolites of the Moon.
Abstract: The article describes the mineral composition and petrochemistry of a unique ancient (more than 1848–2011 MA) igneous rock of the Urals – plagioclase olivine clinopyroxenite. These rocks are considered the oldest in the Urals. In the literature they are described under the name izrandites. They are part of the foundation of the basement of the East...
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Inadequacy of 1D, 2D and 3D Resistivity Inverse Modelling in the Presence of Electrical Anisotropy
Branislav Sretenovic,
Filip Arnaut
Issue:
Volume 8, Issue 2, April 2019
Pages:
102-116
Received:
11 February 2019
Accepted:
9 April 2019
Published:
29 April 2019
Abstract: Universal property of matter is the variation of a certain physical characteristic in different direction. The Substances that do not display this property are an exception. Anisotropy, as this property is named, is also notable in electrical conductivity of minerals, ores, rocks and geological formations. In order to properly define a geological model of an investigated area, it is necessary to account for electrical anisotropy and lateral effects of different origin that are almost always present phenomena. The degree of knowledge of these phenomena determines the quality of interpretation. The effects of electrical anisotropy on 1D, 2D and 3D inversion of apparent resistivity data were examined and the way to detect, quantify and analyse electrical anisotropy in 3D case is proposed. The results of this analysis showed that electrically anisotropic models have led to the totally erroneous results of 3D inversion while the effects of electrical anisotropy on 1D and 2D inversion were less pronounced. Among several existing ways of collecting 3D apparent resistivity data the complete Pole-pole array data set is the only one suitable for detection of electrical anisotropy. Pole-pole resistivity data enable calculating of corresponding resistance or apparent resistivity values for all other collinear or square arrays. This fact makes possible to use standard grid of electrodes in performing 3D Pole-pole apparent resistivity measurements for calculating square array apparent resistivity data. In the special case of vertical stratification (fracturing, schistosity..) this calculated square array data were used for electrical anisotropy analysis thus determining values of coefficient of anisotropy () and mean geometric resistivity (m). The simple two and three layer 1D synthetic anisotropic models, were used to determine parameters of electrical anisotropy by using 3D forward modelling to calculate Pole-pole and then square array apparent resistivity values. The mean geometric resistivity data obtained by using square array, which are orientation-independent, were used for 1D inversion leading to more realistic results. In the case of oblique stratification (lamination, fracturing, schistosity or karstification) crossed square resistivity data can be reconstructed from 3D Pole-pole data set and then can be used to get parameters of electrical anisotropy, namely apparent coefficient of anisotropy (n), mean geometric resistivity (m) and apparent electrical strike (). These parameters provide an indication that investigations of electrical anisotropy should be conducted (by using square and crossed square array) in order to avoid erroneous results of 3D inversion.
Abstract: Universal property of matter is the variation of a certain physical characteristic in different direction. The Substances that do not display this property are an exception. Anisotropy, as this property is named, is also notable in electrical conductivity of minerals, ores, rocks and geological formations. In order to properly define a geological m...
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The Impact of the Processes in the Southern Ocean on ENSO Development
Vladimir Nikolaevich Stepanov
Issue:
Volume 8, Issue 2, April 2019
Pages:
117-125
Received:
1 April 2019
Accepted:
26 April 2019
Published:
15 May 2019
Abstract: The paper presents the review of the model study of the role of the Southern Ocean in the processes of interaction of the ocean-atmosphere system at short time scales impacting the El Niño–Southern Oscillation (ENSO). It is shown that the variability of wind and atmospheric pressure over the Antarctic Circumpolar Current (ACC), together with the effects of the topography and coastline, significantly impact the development of ENSO events. A new paradigm for ENSO is proposed that allows explaining the current weakening of the interrelation between the variability in wind and water volume in the tropical warm pool in the western equatorial Pacific and the onset of ENSO. The weakness of the interrelationship between ENSO and variability in the equatorial warm water volume of the equatorial Pacific, together with wind variability in the western equatorial Pacific, can be explained by the fact that the process occurred in the Southern Ocean recently became a major contributor amplifying ENSO events. The reproduction in numerical models of ocean dynamics for the mechanism found can improve the accuracy of the forecast of El Niño events.
Abstract: The paper presents the review of the model study of the role of the Southern Ocean in the processes of interaction of the ocean-atmosphere system at short time scales impacting the El Niño–Southern Oscillation (ENSO). It is shown that the variability of wind and atmospheric pressure over the Antarctic Circumpolar Current (ACC), together with the ef...
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