This article reports a method for forecasting an earthquake by synchronous anomalies of optical astronomic time-latitude residuals. The so-called optical astronomic time-latitude residuals for a certain astrometric instrument are the rest after deducting the effects of Earth whole motion from the astronomical time and latitude observations determined by the instrument. Forecasting practice for four earthquakes around the Yunnan Observatory occurring after 2010 shows that it does not generate false forecasts, and also does not miss forecasts of major earthquakes. This forecasting practice proves that the synchronous anomalies of astronomical time-latitude residuals can provide effective warning sign for earthquake occurrence around observatory station, thus deserves attention and further study. and Su Youjin, Gao Yuping, Hu Hui.
Purification of quartz using an environment-friendly method is important in the contaminants removal. This paper presents advanced method based on calcination pretreatment combined with ultrasound-assisted leaching, for removing iron impurities from industrial quartz. The solvent used is a mixture comprised by diluted hydrochloric acid and oxalic acid. The effects of experimental parameters were investigated and the purification mechanism was discussed using particle size analyzer, scanning electron microscope and polarized light microscope. SiO2 content of concentrate could be increased from 99.6828% to 99.9047%, which achieved 3N level high purity quartz, and Fe2O3 content reduced from 0.0857% to 0.0223%, under the optimal conditions, i.e., calcination temperature of 900 °C, holding time of 2 h, oxalic acid concentration of 10 g/L, hydrochloric acid concentration of 5%, liquid solid ratio of 5, leaching temperature of 60 °C, ultrasound power of 400 W and treatment time of 30 min. Compared to conventional method, the proposed method significantly accelerates the leaching process and increases the iron removal rate. At the same time, the method also can remove gas-liquid inclusions. and Yang Changqiao, Li Suqin, Bai Jiaxing, Han Shuaishuai.
Secondary deformations are ground movements occurring in areas of ceased underground mining. These are associated with delayed readjustment of rock mass resulting in subsidence, discontinuous deformations (sinks, cracks, etc.) due to destruction of underground, usually shallow, workings, and elevation of ground surface in response of rock mass to rising groundwater levels following the end of mine water drainage. Comparative analysis of secondary deformations in two former mining areas in the first period after cessation of underground hard coal mining is the subject of this study. We used ERS-1/2 and Envisat satellite radar interferometry data processed with PSInSAR technique and GIS to map vertical (in satellite’s line of sight, LOS) movements of the surface and analyse them in relation to location of coal fields and underground water table rise. In the study, two areas have been compared, the Ostrava city in the Czech part of the Upper Silesian Basin and the Wałbrzych Coal Basin in Poland. The results of analyses based on the results of PSInSAR processing between 1995 and 2000 for the Wałbrzych site indicate uplift (up to +12 mm/year) in closed parts of coal fields and subsidence (up to -8 mm/year) in areas of declining mining. Results of PSInSAR analysis over the Ostrava site indicate decaying subsidence after mine closures in the rate of up to -6 mm/year during 1995-2000. Residual subsidence and gentle uplift have been partly identified at surroundings of closed mines in Ostrava from 2003-2010 Envisat data. In Wałbrzych gentle elevation has been determined from 2002 to 2009 in areas previously subsiding. and Blachowski Jan, Jiránková Eva, Lazecký Milan, Kadlečík Pavel, Milczarek Wojciech.
Artefacts in applications of the global gravity field and topographic models based on satellite and terrestrial data of diverse kinds are studied. Various types of artefacts are presented and analysed with the aim to understand how the artefacts originated, how to reduce them (if feasible) and to avoid misinterpretations in geoscience. We work with the gravity aspects (gravity anomalies, the Marussi tensor of the second derivatives of disturbing potential, gravity invariants and their specific ratio, strike angles, and virtual deformations), and with surface or bedrock topography. Examples for the Earth, the Moon, and Mars are presented., Jaroslav Klokočník, Jan Kostelecký, Aleš Bezděk and Gunther Kleteschka., and Obsahuje bibliografii
Diatomite is a siliceous sedimentary rock, and it can be used in many industrial applications due to its high porosity, low density porous and permeable structure, chemical resistance, high purity, high specific surface area, absorptive capacity and to its absorbent properties. The best known Portuguese occurrences of diatomite are located in the regions of Óbidos and Rio Maior. The purpose of this research is to characterize the Rio Maior and Amieira diatomite and beneficiate this rock to be used in some potential applications locally or not. The studied diatomites present a fine texture; chemically the samples have a high SiO2 content, the principal minerlas are quartz and amorphous opal. The studied diatomites benefited with temperature and addition of NaCl (acting as accelerator of the crystallization process), with 5 % of NaCl being reduced the transformation temperature of the amorphous opal in opal C / CT at about 200 ºC. The diatomites from Rio Maior and Amieira in natural state has an enormous potential as absorbent, of heavy metals (e.g. in soil contamination) or dyes (textile industry). These diatomites after beneficiation can be used in construction materials (as additive), being more reactive and crystalline than in the natural state, diatomites can be promoters of mechanical resistance in mortars and geopolymers. and Costa Cristiana, Velosa Ana, Cerqueira Angela, Caetano Paulo, Rocha Fernando.
Set of events from West Bohemian 2008 seismic swarm with known source mechanisms is processed. The events or their slips respectively are clustered into two groups: (i) principal events with slip laying in the main fault plane and (ii) complementary events deviating from that plane. From those slips we constructed image of slip distribution (a new way of data/slip presentation) and from slip distribution and variations we hypothesized about foci zone properties. Namely, we propose that western block is more rigid and compact; the eastern block appears to be constituted from several sub blocks which can interact with each other during the swarm course. Our hypothesis is supported by similar image constructed from relative rupture velocities, which we consider as independent data. The proposed structural model agrees with the existence of the different observed types of source mechanisms. and Kolář Petr, Boušková Alena.
The values of density and velocity in the samples of the predominant rocks from the Archaean section of the Kola superdeep borehole (SG-3) drilled in the northern frame of the Pechenga palaeorift structure have been studied. The main part of rocks of the SG-3 Archaean section is represented by gneisses, schists and amphibolites. Their main rock-forming minerals are plagioclase, hornblende, mica and quartz. The texture of the rocks is mainly medium-grained, the structure is nematogranoblastic and lepidogranoblastic. The parameters of elastic anisotropy were estimated by the acoustopolariscopy method, the density and velocity of compression and shear waves were determined in the lab and the mentioned characteristics were calculated by mineral composition. The measured sample velocities are unusually low, which can be explained by the decompaction effect of deep rocks. The values of the velocity characteristics that are close to those for the conditions of the rock deep occurrence were obtained by calculation with regard to their specific mineral composition. The average values of the velocity of compression and shear waves for gneisses were calculated by mineral composition are 6.38 ± 0.16 km/s and 3.52 ± 0.14 km/s, respectively. The average of the compression wave velocity for schists is 6.40 ± 0.13 km/s, of the shear wave velocity - 3.46 ± 0.09 km/s and for amphibolites 6.84±0.13 km/s and 3.82±0.08 km/s, respectively. The dynamic moduli in different rocks are lower in schists, medium in gneisses and higher in amphibolites., Olga Trishina, Feliks Gorbatsevich and Mikhail Kovalevskiy., and Obsahuje bibliografii
Based on the analysis performed in the Kura geomorphological sub-region of the Caspian coastal zone, it was determined that the sea level rise of 2.43 m in 1976-1996 caused an average annual rate of erosion processes about 75 times higher than accumulation processes. In 1996-2019, the stabilization and the following drop of the sea level of 1.39 m led to an average annual rate of accumulation processes up to 14 times higher than the average annual rate of erosion processes. This pattern is observed along the entire coastline of those periods. Erosion processes in the initial stage (1976-1996) increased the indentation and length of the coastline by almost 2 times, and in the next stage (1996-2019) the intensification of accumulation processes resulted in the smoothing and reduction of the coastline by 35 %. Statistical analysis of coastlines was carried out by processing Landsat satellite images for 1976-2019; each coastline was divided into 14 segments according to geomorphological zones and their morphostructures in the study area. The development forecast for the next 10 and 20 years is provided., Jeyhun Yashar oglu Gasimov., and Obsahuje bibliografii
In this article, the authors use the existing theoretical foundations and partial solutions to provide a general formula, which can be used to determine the value of horizontal deformation factor B for various applications of the Knothe theory. This applies to the calculation of surface deformation not only in the case of hard coal mining, but also in the case of salt mining by borehole. Convergence resulted from mining may cause deformations of caverns used to store liquid and gaseous fuels or the deformations related to the fluidized bed extraction. The calculations for the new analytical model are presented in the examples of the Etzel cavern (Germany) and the Upper Silesian Coal Basin (Poland). and Sroka Anton, Misa Rafał, Tajdus Krzysztof.
The use of rock physics modeling and petrophysical analysis has become an integral part of quantitative seismic interpretation. In the present study, the above-mentioned techniques are applied to the reservoir interval of Basal Sand of Cretaceous age widely distributed in the Lower Indus Basin of Pakistan. The data used for this purpose consists of complete suits of wireline logs from four well A, B, C and D. The primary goal of this work is to understand the trends of seismic parameters such as P-wave velocity (VP), S-wave velocity (VS), bulk modulus, bulk density as a function of fluid saturation and porosity in this sand interval. Petrophysical analysis based on well logs is used to obtain petrophysical properties such as porosity, the volume of shale, fluid saturation, P-wave velocity (VP), S-wave velocity (VS) and density at reservoir conditions. The results show that seismic parameters are very sensitive to fluid saturation, fluid types and rock-forming sediments. Reservoir porosity and fluid saturation control the elastic response of Basal Sand due to which seismic velocities decrease with an increase in porosity and fluid saturation., Perveiz Khalid, Muhammad Arshad, Muhammad Irfan Ehsan, Aziz Ahmad and Shehzad Khurrum., and Obsahuje bibliografii