Results of dipole electric sounding in the area of the Chirkey water reservoir after its filling

The analysis of the data of variations of the apparent electric resistivity of rocks (AR) in the area of the Chirkey HES has been carried out for the period after the water reservoir was filled. For measurements the method of dipole electric sounding has been used with location of potential dipoles around the water reservoir with a distance between them of 5.2–11.3km. The analysis of the data obtained for the period of observations (1976–1988) has shown that the filling of the water reservoir affected the environment for a long time. After it was filled (1975), at different observation points located around the water reservoir a decrease of 1.6–2.4 times was registered in the AR over the period from 1976–1988. This is connected with the process of inundation of the rock mass, which continued for more than 14 years. The process of water filtering into the surrounding rock mass was complicated; that is, it varied in time and space. At the initial stage of the reservoir filling the AR variations of a high amplitude (30–40%) were observed. These variations are considered to be connected with the seismic regime of the area of the water reservoir. A synchronous decrease in the AR, registered at the receiver points was followed by an increase of the number of the earthquakes of energetic class (K = 10). The given anomalous data are connected by an increase in the water filtration into fractured zones, whose filtration features change on being affected by tectonic stresses.     

南海北部陆缘的磁异常特征及居里面深度

为了研究南海北部张裂大陆边缘的地壳热结构,利用船载测量磁力数据,通过功率谱方法反演南海北部陆缘居里等温面,并结合深地震剖面、区域断裂及大地热流分布,讨论了深部热结构状态.结果显示研究区居里面深度在13~26 km之间,在上下陆坡转换带处与莫霍面相交,北东向断裂多位于居里面梯度带上,北西向断裂多具有分割、错断的特点,居里面深度和大地热流值具有相关性.结果揭示了陆架、上陆坡地区磁性体可能主要位于上地壳和下地壳上部,下陆坡及洋壳区地壳与地幔顶部有被磁化的迹象.磁静区位于居里面上隆区边缘,F3断裂和F4断裂之间可能是残留古洋壳.潮汕凹陷和台西南盆地中央隆起是发生底侵的主要区域,F2断裂为其北界.      

Maastrichtian Charophyte Flora from the Jiankou Section of the Jiaolai Basin

The latest Cretaceous strata of the Jiaolai Basin were studied in two scientific cores,including LK-1 drilled by the Institute of Geology,Chinese Academy of Geological Sciences(Li et al.,2018;Li et al.,2020),and JK-1 drilled by the Shandong Institute of the Geological Survey and Institute of Geology,Chinese Academy of Geological Sciences(Xu et al.,2017).However,outcrop sections were poorly studied,and the latest Cretaceous charophyte flora in particular had not previously been adequately documented from outcrops in the Jiaolai area.     

雪峰山基底隆升带及其邻区印支期陆内构造特征与成因

狭义的华南陆块东部包括扬子地块和华夏地块,而雪峰山陆内构造系统是扬子地块的重要组成部分。通过对雪峰山地区印支期地层角度不整合时空分布规律的分析表明,高角度不整合—微角度不整合—平行不整合—整合的空间分布区域依次由东往西递变渐新。根据褶皱变形分析得出,雪峰山地区在印支期发育了北东东向和北北东向2个轴迹方向的褶皱,后期叠加了南北向弧形逆冲推覆构造。区域构造背景和动力学分析表明,扬子地块内部印支期总体北东向的变形形迹与东西轴向的秦岭—大别造山带和扬子地块南部东西轴向的构造线相垂直;其原因是:扬子地块与华夏地块最终陆内收缩变形的时间比扬子与华北沿秦岭—大别造山带的陆间碰撞拼合的时间早,印支早期的先存北北东向构造线在印支晚期由于扬子地块顺时针旋转变位为北东东向,从而决定了印支早期现今北东东向的构造线,随后的第二幕北北东向构造线的形成是在与早期第一幕变形的应力场相同的同一构造应力场作用下形成的。但是,秦岭—大别造山带近东西向的构造线取决于主动大陆边缘,即总体近东西向的华北陆块南缘边界,其原始方位为总体近东西向。这些复杂边界条件和旋转决定了先形成彼此近于垂直的构造线,然后拼接形成现今构造线垂直的格局。     

Cloud Variations under Subtropical High Conditions

The cloud variations under subtropical high(STH) conditions during summers over a ten-year period are studied using combined data from the International Satellite Cloud Climatology Project and the National Centers for Environmental Prediction.The results reveal that clouds mainly experience an isolated evolution in the STHs,which is designated in this study by the 1540 gpm geopotential lines at 850 hPa.In the STH domain throughout the Northern Hemisphere,the average amount of total clouds exceeds 30%.Low clouds dominate in the STH domain,contributing over 60%of total cloud amount within the Pacific subtropical high and over 40%within the Atlantic subtropical high.The prevalence of low clouds in above regions is determined by the circulation pattern around 150°-180°E and 850 hPa,which suppresses both the upward development of the cloud tops and the water vapor divergences near the surface.Furthermore,clouds present great geographical incoherence within the STH domain.In the eastern STHs,the amount of middle and low clouds increases to peak in the early morning and decreases to a trough in the afternoon,while the amount of high clouds remains stable throughout the day.Conversely,in the western STHs,the diurnal amplitude of low and middle clouds is less than three,while high clouds dramatically reach the maximum in the afternoon and drop to the minimum in the evening.Among the nine cloud categories,stratocumulus clouds with greater optical thickness account for the most under STH conditions,no matter their occurrence or amount,causing more shortwave cloud radiative forcing to cool the local atmosphere and surface as a consequence.     

Propagation of a quasi bi-annual impulse close to the moment of the solar magnetic field polarity changing

Some particular features of solar differential rotation have been recently revealed in Abastumani Astrophysical Observatory: in the northern hemisphere of the Sun a propagation of a quasi bi-annual impulse of the rotation residual from the high latitudes to the equator, during the time interval of 1979–1981, was statistically demonstrated. Japaridze and Gigolashvili (1992) proposed that this event might be related with the change of magnetic polarity in the northern hemisphere of the Sun in 1981.To prove this hypothesis an investigation of the MHD equations in the local system of coordinates has been carried out. A homogeneous equation with partial derivatives in the linear approximation was obtained. Its solution is presented analytically. The disturbance of velocity enhances especially at the moment of reversal of magnetic field polarity.     

The gravitation theory in bimetric formulation

The gravitation theory is considered in bimetric formulation with a Lagrangian of the most common type and quadratic with respect to the derivativesg _ik/l of the metric tensor. Restrictions on the dimensionless parameters of the theory are found, basing on the comparison with the Newtonian theory and the analysis of corresponding observational data in the vicinity of the solar system. Propagation of the weak gravitation waves is investigated in the outside gravitational field.     

The Influence of Surface Inhomogeneities On Deep Electromagnetic Soundings of the Earth

Summary. Asymptotic expressions for components of the electromagnetic field of a grounded electric dipole are considered for the model consisting of a thin surface-layer overlapping a stratified medium with a highly resistive screen on the roof. It is shown that the method of spatial derivatives makes it possible to obtain proper estimates of the impedance at distances of r ≥|λ₀| from the nearest edge of the surface anomaly (|λ₀| being the effective depth of the field penetration in the underlying section). the magnetotelluric methods allow one to obtain the true values of impedance, provided r ≥ max {|λ₀|, |/( S ⁻¹+ Z ⁻₀|^1/2} where S is the integrated conductivity of the surface layer, is the transverse resistance of the screen, and Z ⁻₀ is the Tikhonov—Cagniard impedance for the medium underlying the surface layer.     

秦皇岛地区雨滴谱仪和雷达探测的反射率因子差异分析研究

利用布设在秦皇岛市抚宁地区的OTT Parsivel激光雨滴谱仪和卢龙地区S波段天气雷达,对2017—2019年4—9月共23次降水过程进行了观测,并分析了基于雨滴谱参数(滴谱粒子数N(D)和粒子直径大小D₀)计算的雷达反射率因子Z_D和雷达探测的雷达反射率因子Z_R的差异Z_C。结果表明,N(D)主要集中在130～530个范围内,Z_C标准差随着N(D)的增大而逐渐减少;D₀主要集中在0.8～1.6 mm范围内,Z_C标准值在D₀<1.2 mm范围内随着D₀的增大而逐渐减少,D₀在1.2～1.6 mm范围内趋于稳定;Z_D主要集中在15～40 dBZ范围内,Z_C标准差在15～35 dBZ范围内随着Z_D值增大而减小。