Studia Geophysica et Geodaetica

Обрaзовaнuя amмосферных ¶rt;aвленuŭ зaмещaюmся еомеmрuческu более nросmымu мо¶rt;елямu u выво¶rt;umся влuянuе uх мaсс нa уровенные nоверхносmu в месmaх, ¶rt;е ре uсmрuруеmся нaклон. О¶rt;новременно оnре¶rt;еляюmся знaченuя нaклонов, вызывaемых уnру uмu ¶rt;еформaцuямu земноŭ nоверхносmu. Дру uмu косвеннымu влuянuямu nренебре aеmся. Для слычaя мо¶rt;елu вычuслены обе ¶rt;еформaцuu u nосле¶rt;нuмu вызвaнныŭ общuŭ нaклон. Выве¶rt;енные сооmнощенuя ¶rt;ля нaклонa nрuменяюmся к нuвелuрным нaблю¶rt;енuям.

Нa основе лaборamорных uссле¶rt;овaнuŭ можно обьясняmь ре uонaльные ео мa нumные aномaлuu nроuсхо¶rt;ящuе в¶rt;оль внещнuх Флыщевых Кaрnam кaк сле¶rt;сmвuе вознuкновенuя вmорuчно о мa неmuma nроявляюще ося nовыщенuем мa нumноŭ восnрuuмчuвосmu в nорuсmых осa¶rt;кaх uлu в вывеmренных рaно¶rt;uорumaх, нa коmорые влuяюm ре¶rt;укцuонные nроцессы uз-зa nрuсуmсmвuя у лово¶rt;оро¶rt;ов. Эксnерuменmы nокaзaлu, чmо элекmрuческaя nрово¶rt;uмосmь в nрuве¶rt;енных условuях maкже нaрaсmaеm. Былa nре¶rt;ложенa uнmерnреmaцuя aномaльных еофuзuческuх явленuŭ нa mеррumорuu восmочноŭ Морaвuu, ¶rt;е uсmочнuкu nовыщенноŭ нaмa нuченносmu u элекmрuческоŭ nрово¶rt;uмосmu мо уm вознuкamь нa лубuне несколькuх км кaк резульmam ре¶rt;укцuонных nроцессов в орных nоро¶rt;aх.

The ratio of P- to S-wave velocities, VP/VS, is an important parameter characterizing rock composition and fluid saturation. We have studied properties of the ratio in the West-Bohemian seismically active region, using data from the earthquake swarm which occurred here in 2008. The earthquake swarm was well recorded by 23 seismic stations from epicentral distances less than 25 km. We selected a subset of 158 events with local magnitudes between 1.5 and 3.8. Applying the Wadati method to the measured arrival times of P and S waves, we arrived at an average value of VP/VS =1.68 ± 0.01. This differs a little from the value of VP/VS = 1.70, which is routinely used for earthquake locations in the region at present. Moreover, it was recognized that the points in the Wadati graphs for some stations were systematically deviated from the mean straight lines. In particular, the stations with the largest positive deviations (above the mean straight lines) are situated close to the Mariánské Lázně Fault and to some intensive mofettes. Further analyses revealed reduced P- and S-wave velocities along the seismic rays toward these anomalous stations. In our opinion, the seismic waves arriving at the anomalous stations probably propagated along a fault or another zone of weakness. In this way, our results support the hypothesis that the Mariánské Lázně Fault is a deep-seated fault continuing down to the seismically active zone of local earthquakes. From a general point of view, this study demonstrates that even some narrow structural anomalies in the crust, such as fault zones, can be recognized by the simple Wadati method if data from a dense seismic network are available.

The paper presents the testing of the possibility of determining the heights of GPS points in the homogeneous field in the new Croatian Height Reference System (HVRS71) by using the method of height transformation. The testing was made in the area of Zagreb. As part of the field works, normal orthometric heights of 27 GPS points were determined according to the new height system, by transferring the benchmark heights using the geometric levelling method, thus obtaining GPS/levelling points of known ellipsoidal and normal orthometric heights. The GPS/levelling points served as the basis for determining the transformation models that enabled the computation of normal orthometric heights from ellipsoidal heights of any GPS point in the observed area. The empirical data used for modelling were reduced undulation dN values of GPS/levelling points. As part of the dN modelling with parametric functions, the approximation surfaces were obtained on the basis of three polynomials: FN310, FN312 and FN318. The transformation models were also tested using non-parametric Watson and Loess algorithms. The FN318 and Loess models yielded the best results.

Based on the relation between the relative sunspot number R, the number of sunspot groups f0 generated per unit time on the Sun as a whole and their average lifetime T0, and on the extrapolation of time behaviour of f0 and T0, it is proved that abnormally high solar activity may be expected in the first half of the 21st century. At this time, the maximum annual relative sunspot numbers RM of the 11-year cycles should reach values of about 300 units. This abnormally high solar activity in the next century can be understood as the antipole of the Maunderean minimum. This forecast is used to discuss some of the possible consequences of this abnormally high solar activity for the processes on the Earth: changes of climate (heat waves and draughts in Central Europe), in the higher layers of the Earth's atmosphere (anomalous propagation of radio waves, increased effect of the density of the upper atmosphere on the orbits of man-made satellites), in seismicity (increased seismic activity in Europe and Southeast Asia), for technical devices (induced electric currents), in the biosphere. etc.

Four fundamental forms of expansion of the double product of the gravity function into an infinite series are derived. Two isotropic parts are separated, one is expressed by Legendre polynomials and the other by invariants of Wigner's D-matrices.

The thermo-elastic deformations due to the annual temperature variation are computed. The time variation of these deformations is compared with the variation of the slow deformations observed at the tidal station in Vyhne.

We examine the potential of magnetic susceptibility measurements to discriminate different soil drainage classes in the Gandoman region, central Iran. Four soil drainage classes, comprising poorly drained (PD), somewhat poorly drained (SPD), moderately well drained (MWD) and well drained (WD), were identified, and a total number of 48 soil profiles were excavated and studied. The soil samples were collected from all studied profiles from the genetic horizons individually. Magnetic susceptibility was measured at both low (0.46 kHz) and high (4.6 kHz) frequencies. The crystallized and amorphous iron forms were also measured using citrate-bicarbonate-dithionite solution and oxalate-ammonium extracts, respectively. The highest magnetic susceptibility was observed in WD soils, whereas the lowest susceptibility was observed in PD soils. The results of the predictor models developed by discriminate analysis showed that the use of magnetic susceptibility and iron forms could correctly predict about 90.9, 78.6, 85.7 and 88.9% of all profiles in WD, MWD, SPD and PD classes, respectively. Overall, the results indicate that magnetic susceptibility could be applied as a marker for the discrimination of drainage classes in the study area. Magnetic susceptibility is thus a quickly accessible and low-cost indicator for soil drainage classes for landownerships and subsequent analyses.