The effect of initial data in adjusting conditional observations     

Juraj Šütti  Reviewer J. Kašpar 《Studia Geophysica et Geodaetica》1973,17(2):100-105

Summary In the introduction the effect of neglecting the accuracy of the initial data is mentioned in adjusting conditional observations, because this essentially causes the accuracy of the adjusted quantities to be overrated. The effect of changes (errors) of the initial data is investigated for two cases: a) when the initial data are given, unmeasured quantities; b) when the initial data are given and measured quantities which form the conditions of adjustment (e.g., gyrotheodolite directional angles). This effect was rejected in a change of the corrections, in the vrst case according to (14), and in the second according to (18). The effect of the changes (errors) of the initial data was also investigated with regard to the matrix of the co-factors of the adjusted quantities. This matrix, taking into account the errors of the initial data described by matrixQww, and the errors of the measurements themselves, described by matrix (26), is expressed by (31).Dedicated to 90th Birthday of Professor Frantiek Fiala  相似文献   

Genetische Probleme der Zinn-Wolfram-Vererzung im Erzgebirge     

Miroslav Štemprok 《Mineralium Deposita》1967,2(2):102-118

Zusammenfassung Die Zinnvererzungen im Erzgebirge stehen in engen räumlichen Beziehungen zu den Granitkontakten. Dieses Merkmal wird durch eine strukturelle Rolle der konsolidierten Endokontaktpartien der Granite beim Aufstieg der Erzlösungen erklärt. Die Mineralisationslösungen stammen aus den tieferen Teilen der Erdkruste; die Lagerstätten stehenin einer paragenetischen Stellung zu den Graniten. Die Zinn-Wolfram Mineralisation verlief in mehreren Mineralisationsstadien. In den Quarzgängen konnte eine deutliche innere Gangmetasomatose beobachtet werden, bei der ine ältere Quarzgangfüllung verdrängt wurde. Die symmetrischen Salbänder mancher Mineralien um die Quarzgänge sind durch Verdrängung des Quarzes vom Gangkontakt aus gebildet worden. Die Abschnitte der Quarzgänge mit Feldspäten die den Pegmatiten sehr ähnlich sehen, sind durch Metasomatose nach der Greisenbildung entstanden. Die Granitbildung wurde von extensiven Nebengesteinsumwandlungen begleitet bei der Kalifeldspatbildung (I–II), Albitisierung, Vergreisung, Serizitisierung, Kaolinitisierung, und Hämatitisierung unterschieden werden. Die wichtigsten geologischen und mineralogischen Merkmale der Lagerstätten sind in Tabellen zusammengefaßt.

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The tin-tungsten mineralization in the Kruné hory Mts. /Erzgebirge shows a close spatial association with the granite contacts. This feature is explained by the structural control of solid endocontact part of the granite bodies for the import of postmagmatic solutions. The mineralizing solutions were derived from the deeper parts of the earth's crust, the ore deposits being thus in a paragenetic position to the granites. The tin-tungsten mineralization occurred during an interrupted process of metallization in the course of several stages. In the quartz veins a distinct intravenous metasomatism was observed with the replacement of earlier quartz vein fillings. The symmetrical selvages of some minerals around quartz veins originated by the replacement of quartz from the wall contact. The sections of the quartz veins with felspars resembling very closely the pegmatites were formed by the post-greisen metasomatism of the quartz veins. The emplacement of granites was accompanied by extensive wall- rock alterations of which potash- felspatization (I and II), albitization, greisenization, sericitization, kaolinization and hematitization were distinguished. The main geological and mineralogical features of the deposits are summarized in tables.

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A two-stage time series model for monthly hydrological projections under climate change in the Lim River basin (southeast Europe)     

Milan Stojković  Jasna Plavšić  Stevan Prohaska  Dragutin Pavlović  Jovan Despotović 《水文科学杂志》2020,65(3):387-400

ABSTRACT

Climate change projections of precipitation and temperature suggest that Serbia could be one of the most affected regions in southeastern Europe. To prepare adaptation measures, the impact of climate changes on water resources needs to be assessed. Pilot research is carried out for the Lim River basin, in southeastern Europe, to predict monthly flows under different climate scenarios. For estimation of future water availability, an alternative approach of developing a deterministic-stochastic time series model is chosen. The proposed two-stage time series model consists of several components: trend, long-term periodicity, seasonality and the stochastic component. The latter is based on a transfer function model with two input variables, precipitation and temperature, as climatic drivers. The Nash-Sutcliffe model efficiency for the observed period 1950–2012 is 0.829. The model is applied for the long-term hydrological prediction under the representative concentration pathway (RCP) emissions scenarios for the future time frame 2013–2070.  相似文献   

The birthplaces of active regions and X-ray bright points     

R. Howard  L. Fritzová-Švestková  Z. Švestka 《Solar physics》1979,63(1):105-111

A comparison of soft X-ray pictures of the Sun (S-054 experiment of Skylab) with K-line spectroheliograms (Mount Wilson) shows that the X-ray bright points tend to emerge randomly throughout the Ca network pattern. However, all those bright points that developed into active regions emerged at the boundaries of network cells. This suggests that the magnetic flux of active regions comes from greater depths in the convection zone than the shallow flux that gives rise to the random emergence of bright points.Also Physics Department, C-011, University of California at San Diego, La Jolla, Calif., U.S.A.  相似文献   

What should be observed on the sun     

Z. Švestka 《Solar physics》1976,47(1):375-384

Three problems are emphasized in particular: the preflare magnetic field configuration, velocity fields, and the nature of acceleration processes in flares. It is concluded that what we need most urgently are high-resolution hard X-ray, soft X-ray, and EUV-pictures, coronal spectra, and magnetograms with high resolution both in space and time. A space-shuttle equipped with instrumentation of this kind would contribute significantly to our knowledge of the flare process.  相似文献   

Changes of the profiles of spectral lines due to mass transfer in close binaries     

Zdislav Šíma 《Astrophysics and Space Science》1973,24(2):421-448

In this paper, the model of the ring envelope round the primary component and the stream of the gaseous mass flowing from the secondary component to the primary is constructed on the basis of theoretical computations concerning the exchange of the mass between the components of the binary. The paper studies the influence of the gaseous mass on the profiles of spectral lines before and after occultation; the influence of the stream on the profile in case the secondary is near elongation, is also investigated. The line profiles obtained by numerical computations show that their changes caused by outflowing mass should be well detectable from spectrograms taken at particular phase of the binary. Changes in the lines may influence the measurement of radial velocities. The method for distinguishing the influence of the stream from the influence of the ring is described.  相似文献   

A comment on the flare activity in August 1972     

L. Fritzová-Švestková  Z. Švestka} 《Solar physics》1973,29(2):417-419

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Seismic Activity Around and Under Krakatau Volcano,Sunda Arc: Constraints to the Source Region of Island Arc Volcanics     

Špičák  A.  Hanuš  V.  Vaněk  J. 《Studia Geophysica et Geodaetica》2002,46(3):545-565

There is general agreement that calc-alkaline volcanic rocks at convergent plate margins are genetically related to the process of subduction (Ringwood, 1974; Maaloe and Petersen, 1981; Hawkesworth et al., 1997). However, opinions on the mode and site of generation of primary magma for island arc volcanism differ substantially. The site of generation of calc-alkaline magma is thought to be either in the mantle wedge (Plank and Langmuir, 1988; McCulloch and Gamble, 1991) or in the subducting slab (White and Dupré, 1986; Defant and Drummond, 1990; Edwards et al., 1993; Ryan and Langmuir, 1993). We present seismological evidence in favour of the latter concept. A distinctive seismicity pattern around and under the Krakatau volcano was identified during systematic studies of the SE Asian convergent plate margins by means of global seismological data. A column-like cluster of events, probably associated with the dynamics of the volcano, is clearly separated from the events in the Wadati-Benioff zone. The accuracy of hypocentral determinations of the events of the cluster does not differ from the accuracy of the events belonging to the subducting slab. The depths of the cluster events vary from very shallow to about 100 km without any apparent discontinuity. On the other hand, there is a pronounced aseismic gap in the Wadati-Benioff zone directly beneath the volcano at depths between 100-150 km. The Krakatau cluster connects this aseismic gap to the volcano at the surface. The pervasive occurrence of earthquakes in the continental wedge between the subducting slab and the Earth surface bears witness to the brittle character of the continental lithosphere and casts doubt on the existence of large-scale melting of mantle material. The aseismic gap (Hanu and Vank, 1985), interpreted by us as a partially melted domain occurring in subducted slabs in practically all active subduction zones that reach depths greater than 100 km, is here used as evidence for the location of the primary source region of island arc volcanics in the subducting plate.  相似文献   

Formation Of Coronal Mhd Shock Waves – I. The Basic Mechanism     

B. Vršnak  S. Lulić 《Solar physics》2000,196(1):157-180

The formation and evolution of a large amplitude MHD perturbation propagating perpendicular to the magnetic field in a perfectly conducting low plasma is studied. The perturbation is generated by an abrupt expansion of the source region. Explicit expressions for the time and the distance needed for the transformation of the perturbation's leading edge into a shock wave are derived. The results are applied to coronal conditions and the dynamic spectra of the radio emission excited by the shock are synthesized, reproducing metric and kilometric type II bursts. The features corresponding to the metric type II burst precursor and the moving type IV burst in the case of kilometric type II bursts are identified. A specific radio signature that is sometimes observed at the onset of a metric type II burst is found to appear immediately before the shock wave formation due to the associated growth of the magnetic field gradient. Time delays and starting frequencies of bursts' onsets are calculated and presented as a function of the impulsiveness of the source-region expansion, using different values of the ambient Alfvén velocity and various time profiles of the expansion velocity. The results are confronted with the observations of metric and kilometric type II solar radio bursts.  相似文献   

A comparative study of geothermal and meteorological records of climate change in Kamchatka     

V. Čermák  J. Šafanda  L. Bodri  M. Yamano  E. Gordeev 《Studia Geophysica et Geodaetica》2006,50(4):675-695

To reconstruct the recent climate history in Kamchatka, a series of repeated precise temperature logs were performed in a number of boreholes located in a broad east-west strip (between 52 and 54°N) in the central part of Kamchatka west of Petropavlovsk-Kamchatski. Within three years more than 30 temperature logs were performed in 10 holes (one up to six logs per hole) to the depth of up to 400 metres. Measured temperature gradients varied in a broad interval 0 to 60 mK/m and in some holes a sizeable variation in the subsurface temperatures due to advective heat transport by underground water was observed. Measured data were compared with older temperature profiles obtained in the early eighties by Sugrobov and Yanovsky (1993). Even when older data are of poorer precision (accuracy of about 0.1 K), they presented valuable information of the subsurface temperature conditions existing 20–25 years ago. Borehole observations and the inverted ground surface temperature histories (GSTHs) used for the paleoclimate reconstruction were complemented with a detailed survey of meteorological data. Namely, the long-term surface air temperature (SAT) and precipitation records from Petropavlovsk station (in operation since 1890) were used together with similar data from a number of local subsidiary meteo-stations operating in Central Kamchatka since 1950. Regardless of extreme complexity of the local meteorological/climate conditions, diversity of borehole sites and calibration of measuring devices used during the whole campaign, the results of the climate reconstruction supported a general warming of about 1 K characteristic for the 20th century, which followed an inexpressive cooler period typical for the most of the 19th century. In the last three to four decades the warming rate has been locally increasing up to 0.02 K/year. It was also shown that the snow cover played a dominant role in the penetration of the climate “signal” to depth and could considerably smooth down the subsurface response to the changes occurred on the surface.  相似文献