Some remarks on the estimation of geothermal topocorrections     

Jan Šafanda  Reviewer C. Matyska 《Studia Geophysica et Geodaetica》1987,31(3):284-300

Summary The paper deals with some problems connected with the evaluation of the temperature gradient topocorrections for the purposes of the Earth's heat flow measurements. Some errors, occurring in the routine use of the method, suggested by Jeffreys and Bullard (JB method), are discussed. An example of simple topographic features is used to compare this method with the results obtained by a numerical solution of the heat conduction equation (NS method) by means of the finite difference method. The calculations have shown that the NS method is more precise, but its results are very sensitive to the approximation of the surface used. A stepwise approximation of the surface used in a 3-D model of a real mountainous region causes artificial oscillations of the surface values of the topocorrections, and the accuracy of the obtained results is comparable with that of the JB method. Thus, we are faced with the problem of a more appropriate approximation of the relief without the mentioned negative consequences to the superficial values of the topocorrections.

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¶rt;am n, a mnauu ua¶rt;uma mnam nu uu mn nma. u m uu, nu n mu nuu m¶rt;a, m n¶rt; u u a¶rt; (J B m¶rt;). a nu nm mnau mm m¶rt; a u u au mnn¶rt;mu (NS m¶rt;) n n am. uu naau, m NS m¶rt; m JB m¶rt;, m mam u mum annuauu nmu. B a - ¶rt;u ¶rt;mum amu nu¶rt;um mnama annuau u au nm au mnu u mm n mam aua mm JB m¶rt;a. a naa, m n unau num NS m¶rt;a a¶rt; nmu a¶rt; nuuu nmu.

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Robotic telescopes for high energy astrophysics in Ondřejov     

Martin Nekola  René Hudec  Martin Jelínek  Matůš Kocka  Petr Kubánek  Filip Münz  Cyril Polášek  Vojtěch Šimon  Jan Štrobl 《Experimental Astronomy》2010,28(1):79-85

We report on two small aperture robotic telescopes called BART and D50 operated in Ondřejov. Both telescopes are capable of automatic observation of gamma ray burst (GRB) optical afterglows. Coordinates of GRBs are taken from alerts distributed via Internet. Telescopes observe other interesting high energy sources when there is not any alert. The smaller telescope BART has aperture D = 254 mm. The bigger telescope D50 has a primary mirror of diameter D = 500 mm. Both telescopes are controlled by free software package RTS2 and are accessible through Internet. We describe the two telescopes and related software and show some results such as our first observed optical counterpart of GRB.  相似文献   

Tertiary alkaline Roztoky Intrusive Complex, České středohoří Mts., Czech Republic: petrogenetic characteristics     

Roman Skála  Jaromír Ulrych  Lukáš Ackerman  Emil Jelínek  Jaroslav Dostál  Ernst Hegner  Zdeněk Řanda 《International Journal of Earth Sciences》2014,103(5):1233-1262

The ?eské st?edoho?í Mts. is the dominant volcanic center of the Oh?e (Eger) rift zone. It hosts the Roztoky Intrusive Complex (RIC), which is made up of a caldera vent and intrusions of 33–28-Ma-old hypabyssal bodies of essexite–monzodiorite–sodalite syenite series accompanied by a radially oriented 30–25-Ma-old dike swarm comprising about 1,000 dikes. The hypabyssal rocks are mildly alkaline mostly foid-bearing types of mafic to intermediate compositions. The dike swarm consists of chemically mildly alkaline and rare strongly alkaline rocks (tinguaites). The geochemical signatures of the mildly alkaline hypabyssal and associated dike rocks of the RIC are consistent with HIMU mantle sources and contributions from lithospheric mantle. The compositional variations of essexite and monzodiorite can be best explained by fractional crystallization of parent magma without significant contributions of crustal material. On the other hand, the composition of monzosyenite, leuco-monzodiorite and sodalite syenite reflects fractional crystallization coupled with variable degrees of crustal assimilation. It is suggested that the parent magmas in the Oh?e rift were produced by an adiabatic decompression melting of ambient upper mantle in response to lithospheric extension associated with the Alpine Orogeny.  相似文献   

Comparison of response of moss,lichens and attic dust to geology and atmospheric pollution from copper mine     

B. Balabanova  T. Stafilov  R. Šajn  K. Bačeva 《International Journal of Environmental Science and Technology》2014,11(2):517-528

Different sampling media (moss, lichen and attic dust) were used for monitoring the distribution of 15 elements, including certain trace elements, in the vicinity of an intensively exploited copper mine in the east of the Republic of Macedonia. Moss species (Hypnum cupressiforme and Campothecium lutescens), epiphytic lichens (Hypogymnia physodes and Evernia prunastri) and attic dust were collected for comparative analysis for monitoring air pollution. In both cases (lithological and anthropogenic affected areas) for the distribution of elements, the sampling media follows the expression capabilities: attic dust > moss > lichens. Enrichment factors M/L—moss vs. lichen, for plant response to elements distribution and D/L—attic dust vs. lichen, for historical response of elements distribution were significant for Cu and Ni, which were singled out as the main markers for anthropogenic and geogenic distribution. The factor analysis highlighted geogenic (F1: Ni-Cr-Cd-Fe-Al-K-Mn-Zn) and anthropogenic (F2: As-Cu-Pb) association of elements from three types of media samples. For anthropogenic affected areas, T value and F value for Cu content were significant at p < 0.05 and higher enrichment factors were obtained for lichen, moss and attic dust media (3.8, 5.0 and 5.7, respectively). Spatial distribution for element deposition (with emphasis on Cu and Ni) is not disturbed by the significant differences in the sampling media matrix. Treated sample materials (attic dust, moss, lichen) are shown to be useful in determining an anthropogenic impact, as well as the chemical properties or geological background on orographic diverse terrain in the presence of complex geological structure.  相似文献   

Integral transformations of gradiometric data onto a GRACE type of observable     

Michal Šprlák  Pavel Novák 《Journal of Geodesy》2014,88(4):377-390

Integral transformations of gravitational gradients onto a Gravity Recovery And Climate Experiment (GRACE) type of observable are derived in this article. The gravitational gradients represent components of the gravitational tensor in the local north-oriented frame. The GRACE type of observable corresponds to a difference between two gravitational vectors as projected onto the line of sight between the two GRACE satellites. In total, three integral transformations relating vertical–vertical, vertical–horizontal and horizontal–horizontal gravitational gradients with the GRACE type of observable are provided. Spectral and closed forms of corresponding isotropic kernels are derived for each transformation. Special cases show that the integral transformations are general and relate gravitational gradients to many other quantities of the gravitational field, such as the gravitational vector, and its radial and tangential components. Correctness of the mathematical derivations is validated in a closed-loop simulation using synthetic data.  相似文献   

Direct detection of the secondary spectrum of the interacting eclipsing binary TX UMa     

J. Grygar  L. Hřič  R. Komžík  Z. Šíma 《Astrophysics and Space Science》1991,185(2):189-193

Eclipsing binary TX UMa was observed with the D.A.O. high-dispersion spectrographs in 1969–1970, with emphasis on the detailed coverage of the primary minimum. One spectrum was taken exclusively within totality, thus exhibiting an uncontaminated spectrum of the secondary component. This leads to spectral reclassification of the secondary (F6 IV). The narrowing of the line profile of the H-line in totality is interpreted in terms of synchronous rotation of the secondary (v sini80 km s^–1) while the primary rotates faster (v sini130 km s^–1) than synchronously (v sini50 km s^–1). Although the secondary does not fill in its Roche lobe fully, the system exhibits pronounced indications of rather strong physical interaction. This is now supported also by the profound changes of the line profiles of the H-line with phase.  相似文献   

Assess hydrological responses to a warming climate at the Lysina Critical Zone Observatory in Central Europe     

Wenjuan Zheng  Anna Lamačová  Xuan Yu  Pavel Krám  Jakub Hruška  Pavel Zahradníček  Petr Štěpánek  Aleš Farda 《水文研究》2021,35(9):e14281

Climate warming is having profound effects on the hydrological cycle by increasing atmospheric demand, changing water availability, and snow seasonality. Europe suffered three distinct heat waves in 2019, and 11 of the 12 hottest years ever recorded took place in the past two decades, which will potentially change seasonal streamflow patterns and long-term trends. Central Europe exhibited six dry years in a row since 2014. This study uses data from a well-documented headwater catchment in Central Europe (Lysina) to explore hydrological responses to a warming climate. We applied a lumped parameter hydrologic model Brook90 and a distributed model Penn State Integrated Hydrologic Model (PIHM) to simulate long-term hydrological change under future climate scenarios. Both models performed well on historic streamflow and in agreement with each other according to the catchment water budget. In addition, PIHM was able to simulate lateral groundwater redistribution within the catchment validated by the groundwater table dynamics. The long-term trends in runoff and low flow were captured by PIHM only. We applied different EURO-CORDEX models with two emission scenarios (Representative Concentration Pathways RCP 4.5, 8.5) and found significant impacts on runoff and evapotranspiration (ET) for the period of 2071–2100. Results from both models suggested reduced runoff and increased ET, while the monthly distribution of runoff was different. We used this catchment study to understand the importance of subsurface processes in projection of hydrologic response to a warming climate.  相似文献   

Some Aspects of Meteoric Head Echo Velocity Determination     

ŠIMEK  Miloš  Přidal  Petr  Pecina  Petr  Boček  Jaroslav 《Earth, Moon, and Planets》1997,77(1):1-17

Velocity determination of 131 head echoes recorded during Perseid meteor shower observations by the Canadian 2 MW radar, has been performed under the assumption of either their constant velocity or of its linear change with time. Even though the constant velocities concentrated at 60 km s-1 generally accepted for the Perseids, a substantial number of echoes had velocities either lower than 60 km s-1 or greater than this value. The inclusion of variable velocity into considerations led to surprising result that a great portion of the head echoes accelerated (3 possibly decelerating echoes in comparison with 33 accelerating cases on the level of relative standard deviations of output parameters not exceeding 10%). It seems that the allocation of the ionization responsible for the head echo is not entirely identical with the instantaneous meteoroid position. As a consequence, the velocity derived from the measured head echo coordinates can differ from the velocity of parent body. We are not able to explain this finding at present. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Estimation of groundwater recharge rates using soil-water isotope profiles: a case study of two contrasting dune types on Langeoog Island,Germany     

Post  V. E. A.  Zhou  T.  Neukum  C.  Koeniger  P.  Houben  G. J.  Lamparter  A.  &#;im&#;nek  J. 《Hydrogeology Journal》2022,30(3):797-812

Hydrogeology Journal - The creation of artificial dunes for coastal protection may have important consequences for freshwater lenses in coastal aquifers. The objective of this study was to compare...  相似文献   

Integral formulas for computing a third-order gravitational tensor from volumetric mass density,disturbing gravitational potential,gravity anomaly and gravity disturbance   总被引：1，自引：1，他引：0  

Michal Šprlák  Pavel Novák 《Journal of Geodesy》2015,89(2):141-157

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