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1.
According to the fact that the Xinfengjiang reservoir earthquakes are caused mainly by water seepage, this paper using the data ofM s⩾2. 0 earthquakes, studies the hydraulic diffusivity of the mainshock zone by the expansion of the distribution area of epicenters. It is indicated thatin-situ hydraulic diffusivity during the preshock activity of the Xinfengjiang reservoir region was about 6. 2 m2/s. However, after the main shock, thein-situ hydraulic diffusivity in the main shock region increased by fifty percent, that is to say, to 9. 7 m2/s. During the long period after main shock occurrence thein-situ hydraulic diffusivity was affected by significant anisotropy of the medium and fluctuation of water level. No regularity can be found. In addition, we compare the diffusivity found by experiment with rock samples collected with thein-situ hydraulic diffusivity estimated. It is shown that the diffusivity of rock samples with fractures is about the same as the diffusivity estimatedin-situ. However, the diffusivity of whole rock samples is 3 orders of magnitudes smaller than that estimatedin-situ. Finally, we discuss the limits on the method by the expansion of distribution area of epicenters in the study of reservoir induced seismicity. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 364–371, 1991. This subject is sponsored by the Chinese Joint Seismological Science Foundation.  相似文献   

2.
Conclusion Based on the analysis about the law of deformation rate, the concepts of the deformation rate of precursor, and its stress drop, and the stress drop of instability are discussed. According to the obtained deformationu 0 corresponding to the maximum stress, the unstable pointu 1 and the stable pointu 2 of equilibrium, the complete process of rock failure can be divided into four stages quantitatively, corresponding to “the steady stage I”, “the precursor stage II”, “the unstable stage III” and “the later stage IV” of rock failure respectively, which can be used to simulate the complete course of earthquake. This kind of similarity between the complete process of rock failure and the complete course of earthquake suggests clearly the direction to reveal the law being of universal significance for the simulation of the earthquake in the laboratory experiments. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 517–521, 1991.  相似文献   

3.
This paper systematically summarized the relation of the abnormal change of He and H2 dissolved gasses in deep hot-water well at Beijing No. 2 Cotton Mill and their relation with seismicity of the region. An empirical formula for the relation of the precursory anomaly of He and H2 gasses with the magnitude and occurrence time of earthquake has been derived. Two events of magnitude greater than 5 in North China had been successfully predicted by using this formula. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 490–497, 1993.  相似文献   

4.
The features of fracturing and dissolving of Yunnan marble in distilled water near the critical temperature have been studied experimentally. The results indicate that the mechanical parameters of the samples (fracture strength, Young’s Modulus, shear fracture energy and fracture toughness) drop with the temperature of the environment water, near the critical temperature (380°C), these parameters have sudden changes (drop), then keep stable values roughly. The contents of some chemical materials in the water, PH value and conductivity at every experiment temperature have been analysed and measured. At 380°C, there all exist sudden changes. According to the results, it is pointed out that the sudden changes are related to strong stress corrosion of water near its critical temperature to the rock and the exist and its migration of the water solution near the critical temperature in the crust have important significance to the earthquake source process, the formation cause of the low-focal depth earthquakes in the crust. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 156–163, 1992. This work was sponsored by the Chinese Joint Seismological Science Foundation.  相似文献   

5.
We have collected 432 vertical component records from 45 stations of new CENC （China Earthquake Network Center） in Chinese mainland and adjacent regions. These records were used to calculate Q0 （Q at 1Hz） and η values of Lg coda from each station by the stack spectral ratio （SSR） method. Then the tomography method was applied to obtaining lateral variation of Q0 and η values in Chinese mainland and adjacent regions. The result indicates that Q0 value varies between 150 and 600 in the studied areas. Yunnan, southwest Sichuan, and northwest Myanmar show the lowest Q0 value （Q0〈240） and the crust of these regions is characterized by complicated crack and strong hydrothermal activity. The highest Q0 value （Qo〉510） exists in the border of southern Mongolia, Alxa and Ordos block. The η value varies between 0.45 and 0.75 in Chinese mainland and its adjacent regions.  相似文献   

6.
Taking Huanglong Ravine and Kangding, Sichuan, and Xiage, Zhongdian, Yunnan, as examples, the authors summarize the hydrogeochemical and carbon stable isotopic features of the geothermal CO2-water-carbonate rock system and analyze the CO2 sources of the system. It was found that the hydrogeochemical and carbon stable isotopic features of such a system are different from those of shallow CO2-water-carbonate rock system, which is strongly influenced by biosphere. The former has higher CO2 partial pressure, and is rich in heavy carbon stable isotope. In addition, such a geothermal system is also different from that developed in igneous rock. The water in the latter system lacks Ca2+, and thus, there are few tufa deposits on ground surface, but it is rich in light carbon stable isotope. Further analysis shows that CO2 of the geothermal CO2-water-carbonate rock system is a mixture of metamorphic CO2 and magmatic CO2.  相似文献   

7.
How to restore the residual organic carbon and residual hydrocarbon-generating potential is discussed based on the hydrocarbon degradability of source rock. The results indicate there is linear function relationship between the restoring coefficient of residual organic carbon (Kc) and the vitrinite reflectance (R o%) of various kinds of source rock, but the relationship is secondary functional between the restoring coefficient of residual hydrocarbon-generating potential (Ks) and the vitrinite reflectance (R o%). It is pointed out thatKc = (1 -Dresidual)/(1 -D primary),Ks= Kc (D primary/D residual). The restoration of residual organic carbon and hydrocarbon-generating potential of the Cambrian and Ordovician highly mature marine carbonate in the Tarim Basin and North China region shows that the lower limit value of hydrocarbon generating potential and the organic matter abundance of carbonate source rock are basically the same as that of clastic rock. The technical difficulty in hydrocarbon generating evaluation of highly mature and overmature carbonate is solved.  相似文献   

8.
In the light of the single scattering model of coda originating from local earthquakes, and based on the aftershock coda registered respectively at the 4 short period stations installed near the foci shortly after theM7.6 Lancang andM7.2 Gengma earthquakes, this paper has tentatively calculated the rate of amplitude attenuation and theQ c-value of the coda in the Lancang and Gengma areas using a newly-founded synthetic determination method. Result of the study shows the rate of coda amplitude attenuation demonstrates remarkable regional differences respectively in the southern and northern areas. The southern area presents a faster attenuation (Q c=114), whereas the northern area shows a slower attenuation (Q c=231). The paper also discusses the reasons causing such differences. Result of the study also suggests a fairly good linear relation between the coda source factorA o(f) and the seismic moment and the magnitude. Using the earthquake scaling law, the following formulas can be derived: lgM 0=lgA 0(f)+17.6,M D=0.67lgA 0(f)+1.21 and logM 0=1.5M D+15.79. In addition, the rates of amplitude attenuationβ s andβ m are respectively calculated using the single scattering and multiple scattering models, and the ratioβ s/βm=1.20−1.50 is found for the results respectively from the two models. Finally, the mean free pathL of the S-wave scattering in the southern and northern areas are determined to be 54 km and 122 km respectively by the relations which can distinguish between the inherentQ i and scatteringQ s, testify to this areas having lowQ-values correspond to stronger scatterings. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 71–82, 1992. This study is partly supported by the Seismological Science Foundation of the State Seismological Bureau of China, and the present English version of the paper is translated from its Chinese original by Wenyi Xia, Seismological Bureau of Yunnan Province.  相似文献   

9.
Using the data set of about 1 Hz Lg amplitudes from 80 stations in the six eastern provinces of China, the ratios of horizontal to vertical amplitude of Lg waves,H/Z are determined. The mean lg(H/Z)-value is equal to 0.13. For the station bases of soft deposit,granite and sedimentary rock, lg(H/Z)-values average 0.55, 0.04 and 0.10, respectively. For the three kinds of station bases, the station terms of horizontal amplitude,C h average 0.65, −0.09 and 0.00; that of vertical amplitude,C z average 0.32, −0.04 and 0.00, respectively. There are the relations betweenC h ,C z and lg(H/Z):C h =0.01+2.10C z andC h =−0.15+1.46 lg(H/Z). The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 281–286, 1991. Project sponsored by the Chinese Joint Seismological Science Foundation.  相似文献   

10.
Two rock samples with different structures and materials were deformed under a biaxial loading system, and multipoint strain measurements were performed for each sample. The distribution of strain anomalies during the deformation and the instability process were analyzed by using C v value put forward by WANG Xiao-qing and CHEN Xue-zhong, et al, a parameter to describe the heterogeneous distribution of earthquake precursors, so as to examine the method of C v value and to explore its physical meaning experimentally. The result shows that the change of C v value is correlated to the change of deformation characteristics and is an effective parameter to describe the heterogeneity of precursor distribution. C v value increases firstly and then decreases before the instability, and the instability occurs when C v value decreases to the level before increasing. This indicates that C v value may be a useful parameter for earthquake prediction. Foundation item: Chinese Joint Earthquake Sciences Foundation (9507435).  相似文献   

11.
In this paper the relation between fault movement and stress state in deep crust is discussed, based on synthetic analysis of the crustal stresses measured over the world and the concerned data of focal mechanism. Using Coulomb criterion for shear failure and frictional slip, analytical expressions for estimating stabilities of intact rock and existing fault in the crust and for identifying the type of faulting (normal, strike-slip or thrust fault) are derived. By defining the Failure FunctionF m and the Fraction FunctionF f, which may describe steadiness of crustal rock and existing fault, respectively, a synthetic model is set up to consider both fracturing mechanism and the sliding mechanism. By this model, a method to study stability and unstable behavior of crustal rock and fault at different depths is given. According to the above model, quantitative study on the crustal stability in the North China plain is made in terms of the measured data of hydraulic fracturing stress, pore-fluid pressure, terrestrical heat flow in this region. The functionsF m andF f and the shear stresses on faults with different strike angle and dip angle at various depths in this region are calculated. In the calculation the constraint condition of fault movement obeys Byerlee’s Law, and the depth-dependent nonlinear change in the vertical stress due to inhomogeneity of crustal density and the high anomalous pore-fluid pressure in deep crust of this region are considered. The conclusions are: the unstable behavior of the crust in the North China plain is not failure of crustal rock but slip on existing fault; the depth range where stick-slip of fault may happen is about from 8 to 20 km or more; stability of steep fault is lower than that of gentle sloping fault; the shear stresses in the range where may occur stick-slip are nearly horizontal; the steep faults trending from NNE to NE in this region are liable to produce strong earthquakes, whose co-seismic faultings are, for the most part, right lateral slip; the change in pore-fluid pressure in depth remarkably affects the stability of the crust and the increase in pore-fluid pressure, therefore, would be an important factor exciting strong earthquake in this region. The above theoretical inferences are consistent with the data measured in this region. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologia Sinica,13, 450–461, 1991. This work is supported by Chinese Joint Seismological Science Foundation.  相似文献   

12.
Abstract

The spatial position of the Mu?nica River catchment in the Dinaric Karst results in specific conditions of the drainage, distribution and chemical characteristics of the surface water and groundwater. This catchment is mountainous, located between 930 and 1985 m above sea level. The chemical characteristics of the waters are strongly dependent on the local lithological composition and the precipitation regime. The dominant cations are Ca2+ and Mg2+, and anions HCO3 - and SO4 2-. The surface water is characterized by low and medium mineralization, with resultant soft, medium-hard and very-hard total hardness levels. The groundwater is more mineralized than the surface water. Gacko Town and its associated thermal power plant, Gacko 1, which are located in the southern part of the Mu?nica River catchment, have no modern facilities for sewage and wastewater transport or treatment. In order to prevent further water quality deterioration and to enable its sustainable use, it is recommended to ensure adequate protection measures in the catchment area.

Editor Z.W. Kundzewicz; Associate editor S. Faye

Citation Banjak, D. and Nikoli?, J., 2012. Hydrochemical characteristics and water quality of the Mu?nica River catchment, Bosnia and Herzegovina. Hydrological Sciences Journal, 57 (3), 562–575.  相似文献   

13.
Krainov  S. R.  Ryzhenko  B. N. 《Water Resources》2002,29(1):21-32
The problem of the diversity of the geochemical types of carbon dioxide waters (CDW) in petrografically and mineralogically uniform crystalline rock masses is solved with allowance made for the effect of different boundary conditions (physicochemical parameters) on the geochemical effect of interaction in the rock–water system. The formation of the entire geochemical spectrum of CDW in crystalline rock masses is shown to be explicable on the basis of a model of interaction in granite–water systems at different mass ratios of reacting rock (S) and water (L), different temperatures T, and equilibrium concentrations of dissolved CO2 (P CO2).  相似文献   

14.
Abstract

Mathematical transformation models of TDS (total dissolved salts) and organic substance concentration as BOD5 (biochemical oxygen demand) in water of the Angara River and the proposed Boguchan Reservoir have been developed. Having filled the reservoir to a water level of 208 m, in an average year it is shown that increase in surface water mineralization is expected in the cross-section of Boguchan Hydroelectric Power Station giving TDS of up to 20–40 mg/dm3, and values of BOD5 will increase to 2.0–3.9 mgO2/dm3. In a low-water year the value of BOD5 may be as great as 5 mgO2/dm3; mineralization, in contrast, decreases. Several years after reservoir filling, the values of BOD5 would decrease, but water quality of the upper part of the reservoir would still depend on the degree of treatment of wastewater discharged to it.

Editor D. Koutsoyiannis

Citation Savichev, O.G. and Matveenko, I.A., 2013. Evaluation of chemical composition changes of surface water in Boguchan Reservoir (Siberia, Russia). Hydrological Sciences Journal, 58 (3), 706–715.  相似文献   

15.
This paper presents a robust H∞ output feedback control approach for structural systems with uncertainties in model parameters by using available acceleration measurements and proposes conditions for the existence of such a robust output feedback controller. The uncertainties of structural stiffness, damping and mass parameters are assumed to be norm-bounded. The proposed control approach is formulated within the framework of linear matrix inequalities, for which existing convex optimization techniques, such as the LMI toolbox in MATLAB, can be used effectively and conveniently. To illustrate the effectiveness of the proposed robust H∞ strategy, a six-story building was subjected both to the 1940 El Centro earthquake record and to a suddenly applied Kanai-Tajimi filtered white noise random excitation. The results show that the proposed robust H∞ controller provides satisfactory results with or without variation of the structural stiffness, damping and mass parameters.  相似文献   

16.
In the strip limestone mine in Guiding county, Guizhou Province the shear and frictionin situ tests of rock body were made for the three typical inclined weak bands C 3 1 /C 3 1 , C 3 1 /C 2 2 and C 2 2 /C 2 1 . The tests were made according to the second scheme of cuneate sample of the standards on rock mechanics test of Water Conservancy and Electricity Ministry. The changes of the resistivity in the weak band and the acoustic speed across the weak band were measured in the same time. The apparent resistivity data, obtained for 8 samples on 27 measure lines in 38 cycle tests, show that the apparent resistivity changes have rather obvious characters as follows: 1. At shear and friction stage, the change of the apparent resistivity accelerates after the yield point, and reaches the maximum of change rate and change amplitude near fracture point (except the lines with resistivity invariant); 2. On the same sample, the resistivity changes are different on the various lines and related to the location settled the lines, there are some “sensitive” location; 3. At the stage of preloading normal stress before shearing, the resistivity decreases on most lines, but on a few lines the resistivity does not changes; 4. After unloading shear stress, the resistivity could not recover completely and the hysteresis of resistiviity takes place on a few lines. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 217–223, 1993. Support for this research was received from Guiding strip limestone mine, Guizhou Organic Chemistry Factory. This research is supported by the Chinese Joint Seismological Science Foundation.  相似文献   

17.
A tomographic study of the V p and V p/V s structures in the crust and upper mantle beneath the Taiwan region of China is conducted by simultaneous inversion of P and S arrival times. Compared with the previous tomographic results, the spherical finite difference technique is suitable for the strong heterogeneous velocity structure, and may improve the accuracy in the travel time and three-dimensional ray tracing calculations. The V p and V p/V s structures derived from joint inversion and the relocated earthquakes can provide better constraints for analyzing the lateral heterogeneity and deep tectonic characters in the crust and upper mantle. Our tomographic results reveal significant relations between the seismic wavespeed structure and the tectonic characters. In the shallow depth, sedimentary basins and orogen show distinct wavespeed anomalies, with low V p, high V p/V s in basins and high V p, low V p/V s in orogen. As the suture zone of Eurasian Plate and Philippine Sea Plate, Longitudinal Valley is characterized by a significant high V p/V s anomaly extending to the middle-lower crust and upper mantle, which reflects the impact of rock cracking, partial melting, and the presence of fluids. In the northeast Taiwan, the V p, V p/V s anomalies and relocated earthquakes depict the subducting Philippine Sea Plate under the Eurasian Plate. The high V p of oceanic plate and the low V p, high V p/V s atop the subducted oceanic plate extend to 80 km depth. Along the east-west profiles, the thickness of crust reaches 60 km at the east of Central Range with eastward dipping trend, which reveals the eastward subduction of the thickened and deformed crust of the Eurasian continental plate. Supported by Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX3-SW-234-2), National Basic Research Program of China (Grant No. 2007CB411701), National High Technology Research and Development Program of China (Grant No. 2006AA09A101-0201) and National Natural Science Foundation of China (Grant Nos. 40804016, 40704013)  相似文献   

18.
This paper introduces how the ratioR of the characteristic stiffness of rock samplevs. the stiffness of testing machines would influence the rupturing process and the acoustic emission (AE) on the part of the tested rock samples. Result of the experiment shows: WhenR>0.20, the rock sample would rupture abruptly; whereas whenR<0.20, the rock samples would rupture slowly. When the samples rupture abruptly, the time-dependent variation of the AE rate takes such a pattern:peak value—stable low values—rises to the maximum value (concentration)—drops back to the minimum value (quiescence)—(rises again)—ruptures. Moreover, smallerR-value tends to be associated with longer quiescence and vice versa. WhenR>1.50, no pre-failure quiescence is detected. When the rock samples rupture slowly, the variation pattern of the AE rate (after the stress has increased to more than 50% of the rupturing stress) is as the following:stable low (or high) values—rises (or drops) to its maximum (or minimum) values and then continues for some time—ruptures. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 223–233, 1991. This study is supported by the Chinese Joint Seismological Science Foundation.  相似文献   

19.
Triaxial compressive experiments of porous rock samples were carried out under various confining pressures and initial pore pressures without drainage; axial strain and pore pressure were observed versus differential stress. The results of such experiments show that pore pressure increases with increase of differential stress at low differential stress; pore pressure decreases with increase of differential stress at medium and high differential stress. Pore pressure also increases with large amplitude decrease of differential stress at high differential stress. Based on such experiments, it is suggested that water table anomaly before an earthquake reflects the change of differential stress in crustal rocks. The anomalous behavior of water tables in the epicentral and peripheral areas before the great Tangshan earthquake of July 28, 1976 are explained by such suggestion. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,13, 88–95, 1991. This study is supported by the Chinese Joint Seismological Science Foundation. Professor Yongtai Che gave us much help in applying fund support and supplying earthquake case histories.  相似文献   

20.
In the Jungwon area, South Korea, two contrasting types of deep thermal groundwater (around 20–33 °C) occur together in granite. Compared to shallow groundwater and surface water, thermal groundwaters have significantly lower δ18O and δD values (> 1‰ lower in δ18O) and negligible tritium content (mostly < 2 TU), suggesting a relatively high age of these waters (at least pre-thermonuclear period) and relatively long subsurface circulation. However, the hydrochemical evolution yielded two distinct water types. CO2-rich water (PCO2 = 0.1 to 2 atm) is characterized by lower pH (5.7–6.4) and higher TDS content (up to 3300 mg/L), whereas alkaline water (PCO2 = 10− 4.1–10− 4.6 atm) has higher pH (9.1–9.5) and lower TDS (< 254 mg/L). Carbon isotope data indicate that the CO2-rich water is influenced by a local supply of deep CO2 (potentially, magmatic), which enhanced dissolution of silicate minerals in surrounding rocks and resulted in elevated concentrations of Ca2+, Na+, Mg2+, K+, HCO3− and silica under lower pH conditions. In contrast, the evolution of the alkaline water was characterized by a lesser degree of water–rock (granite) interaction under the negligible inflow of CO2. The application of chemical thermometers indicates that the alkaline water represents partially equilibrated waters coming from a geothermal reservoir with a temperature of about 40 °C, while the immature characteristics of the CO2-rich water resulted from the input of CO2 in Na–HCO3 waters and subsequent rock leaching.  相似文献   

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