Treatment of rotation errors in the final adjustment of GPS baseline components     

László Bányai 《Journal of Geodesy》1991,65(2):102-108

Summary The significant coordinate difference changes of the same baselines, measured in different observing sessions, may be interpreted as the rotation around the station held fixed during the differenced processing, if the length changes of these baselines show random behavior. These rotation errors can significantly bias the final network adjustment based on redundant observing sessions and a relative approach. The Gauss-Helmert model with the estimation of the stochastic properties of the rotation errors is the most effective investigated approach. The standard deviation of the baseline length differences between those derived from a precise geodetic network and derived by Trimvec relative positioning software improved by a factor 2.4 after the final network adjustment using the introduced Gauss-Helmert model.  相似文献   

Computer estimation of intensities: The 1985 Berhida,Hungary, earthquake     

Tibor Zsíros  Péter Mónus  László Tóth 《Pure and Applied Geophysics》1990,132(3):533-543

In this paper a computerized method for the intensity estimation from macroseismic observations is presented. The successive steps of the MSK intensity scale (2° to 10°) receives weights according to the observations marked on the earthquake questionnaires. These weights are summed for the individual scale steps. The distribution of these summed weights and their relation to an experimentally chosen function of the criterion make it possible to estimate the appropriate intensity value and its reliability. By computer evaluation of earthquake reports an objective comparison of estimated intensities given by different seismologists can be made, provided that uniform earthquake questionnaires are used. The application of this method will result in more homogeneous intensity data.  相似文献   

Determination of total carbonate content in some representative loess-paleosol profiles     

László Gerei  János Balogh  Magda Reményi 《GeoJournal》1995,36(2-3):187-188

Samples taken from loess and paleosols were examined for carbonate content. The main results were as follows:

1. The carbonate content measured differed significantly when the samples were analysed jointly with the concretions occurring in them or separately from these constituents.
2. Solubility of different carbonates (calcite, dolomite, aragonite etc.) was found different. This factor also might have influenced the measured total amounts of carbonates.

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Caprock analysis from the Mihályi-Répcelak natural CO<Subscript>2</Subscript> occurrence,Western Hungary     

Csilla Király  Ágnes Szamosfalvi  László Zilahi-Sebess  Péter Kónya  István János Kovács  Eszter Sendula  Csaba Szabó  György Falus 《Environmental Earth Sciences》2016,75(8):635

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Submicroscopic accessory minerals overprinting clay mineral REE patterns (celadonite–glauconite group examples)     

Erzsébet Tóth  Tamás G. Weiszburg  Teresa Jeffries  C. Terry Williams  András Bartha  Éva Bertalan  Ildikó Cora 《Chemical Geology》2010,269(3-4):312-328

Samples of glauconite, representing different stages of glauconitisation, as well as different formation environments, were analysed for rare earth elements (REE) and other trace elements using a combination of bulk sample and spatially-resolved in situ techniques. The results indicate that the high-sensitivity, spatially-resolved technique of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) produces values up to two orders of magnitude lower than the bulk sample analyses. This suggests that submicroscopic rare earth element-bearing phases are distributed within the glauconite aggregates comprising the bulk samples. Analytical scanning electron microscopy (ASEM) revealed the presence of micrometre-sized grains of apatite and pore filling precipitates of an unidentified (REE, Ca)-phosphate (approximate composition Ca_0.3–0.4(Ce_0.4La_0.1–0.2Nd_0.1)PO₄) in some glauconite grains.The inherent REE concentrations of the glauconite aggregates (i.e., glauconite crystallites without accidental mechanical inclusions or authigenic, not layer silicate mineral precipitates) was found to be relatively low (e.g., typically less than 100 ppm), and this value decreased with increasing glauconitisation (smectite–mica transformation through a series of recrystallisation processes). These results suggest that the REEs substitute for Ca in the interlayer space of the layer silicate structure and, therefore, the REE content decreases as Ca is progressively removed from the interlayer (smectite–mica transition).LA-ICP-MS, when combined with electron probe microanalysis (EPMA) or ASEM, offers an opportunity to exclude submicroscopic accessory minerals from glauconite trace element analyses, and so produces reliable trace element data for the respective minerals which host those elements.These results illustrate that accessory minerals are difficult to eliminate from clay samples, and that care needs to be taken in the interpretation of clay mineral REE distributions, irrespective of the aggregation state of the studied clay (i.e., whether finely dispersed within the sedimentary rock, or forming millimetre-sized aggregates). Model calculations showed that authigenic apatite associated with the studied green marine clays tends to have higher REE content than “bioapatites”, the total REE content being above 10 000 ppm.  相似文献   

MV-WG: a new multi-variable weather generator     

Nándor Fodor  Ildikó Dobi  János Mika  László Szeidl 《Meteorology and Atmospheric Physics》2010,107(3-4):91-101

This paper presents a new stochastic multi-variable weather generator (MV-WG) and compares its performance with LARS-WG version 4.0. Daily data of 109 meteorological stations from a North American database were used in a twofold comparison of the two generators: (1) the capability of reproducing the mean and variance of annual, seasonal and monthly values, and (2) the capability of reproducing extreme weather events were compared. Both generators did very well on imitating the mean and the variance of the monthly values of the investigated variables, but both showed a more moderate performance as far as the generation of extreme events was concerned. The three-parameter Weibull function, which is first introduced in MV-WG, was found to be a powerful tool to describe not only the distribution of the daily precipitation amounts, but also the distribution of dry and wet spell lengths, as well.  相似文献   

Temperature — composition relationships of authigenic micaceous minerals in the Los Azufres geothermal system     

M. Cathelineau  G. Izquierdo 《Contributions to Mineralogy and Petrology》1988,100(4):418-428

Smectite, illite, celadonite and chlorite are the major products of alteration of rhyolites and andesites, in the upper part of the Los Azufres geothermal system. Changes in mineral assemblages and composition of phases are observed as a function of depth and host rock lithology. Two different sequences characterize the rhyolites and the andesites from the surface to a depth of about 1500 m: kaolinitesmectite (±interlayered illite/smectite)illitemuscovite (rhyolites), and kaolinitesmectite (±interlayered illite/smectite)illite+celadoniteillite+chloritechlorite (andesites).Illite, and chlorite at depth, are largely dominant. Similar substitutions and correlations among chemical constituents characterize illites from rhyolites or andesites, but their compositions in the two host rock lithologies exhibit slight but significant differences, especially in their Fe and Mg contents which are the highest in illites from andesites. Illite exhibits progressive changes in composition with depth: a strong increase in the K content in the interlayer, together with an increase of the Fe content in the octahedral site. These changes correspond to a slight increase in the molar fraction of Fe-(Mg) celadonite end-members, and mostly to a dramatic decrease of pyrophyllite with increasing temperature.Temperature of the mineralogical and compositional changes was estimated from fluid inclusions studies, combined with other geothermometric approaches (chemical geothermometers and direct measurements). Variation of X-pyrophyllite with temperature is proposed as a geothermometer for different host rock lithologies. Transitions between the stability fields of illite±interstratified illite-smectite and illite+chlorite is around 200±30° C, and between illite+chlorite and chlorite around 290±20° C.  相似文献   

Moisture source diagnostics and isotope characteristics for precipitation in east Hungary: implications for their relationship   总被引：1，自引：0，他引：1  

Emese Bottyán  Tamás Weidinger  László Haszpra  Krisztina Kármán 《水文科学杂志》2017,62(12):2049-2060

Knowledge relating to the relationship between the characteristics of precipitation and sources of moisture is essential to improve our understanding of the global water cycle. This study presents the first quantitative estimation of the moisture source regions combined with stable isotope analyses for precipitation at K-puszta, east Hungary. The contributions of the following moisture sources were diagnosed according to the sector analysis of 4-day backward trajectories together with the calculation of evaporation and precipitation fluxes based on the specific humidity: Mediterranean region (57.0%), local moisture (14.8%), Atlantic region (14.2%), Northern Europe (7.4%) and Eastern Europe (6.6%). The δD and δ¹⁸O values of daily precipitation were measured and the deuterium excess (d-excess) was calculated. The d-excess showed systematic differences among the marine sources, reflecting the characteristics of the moisture source area. The results suggest that the stable isotope composition of precipitation preserves information regarding the origin of the water vapour.  相似文献   

Coastal boulder deposit as evidence of an ocean-wide prehistoric tsunami originated on the Atacama Desert coast (northern Chile)     

Manuel Abad  Tatiana Izquierdo  Miguel Cáceres  Enrique Bernárdez  Joaquín Rodriguez-Vidal 《Sedimentology》2020,67(3):1505-1528

A Late Holocene cliff-top deposit of large boulders well above the limits of modern storm waves is described from the southern coast of the Atacama Desert (northern Chile). The largest moved boulder weighs >40 t and field data point to a flood height >18·5 m above high tide level and an inland penetration greater than 284 m from the cliff edge. The minimum flow velocity needed for particle entrainment was estimated as 10·1 ms⁻¹ and the most likely processes of sediment deposition for different boulders were deduced. The boulder distribution, sorting and orientation of imbricated debris, together with the significant wave height of extreme storms reported and the occurrence of interplate earthquakes in the study area indicate that the deposit records a single event, interpreted here as a tsunami wave train rather than exceptional storm waves. The boulder field was dated to between the 13th and the 16th Centuries ce and possibly correlates with the 1420 Oei orphan tsunami, that affected the eastern coast of Japan. A magnitude of 8·8 to 9·4 has been estimated for the earthquake, which may be one of the larger events of a super-cycle of earthquakes in the southern Atacama Desert. These cycle-ending earthquakes involve large rupture areas (lengths in excess of 600 km) and highly destructive ocean-wide tsunamigenic events.  相似文献   

A multi-site campaign on the long period variable subdwarf b star PG 1627+017     

Suzanna Randall  Gilles Fontaine  Elizabeth Green  Dave Kilkenny  Lisa Crause  Oliver Cordes  Simon O’Toole  Lázló Kiss  Bi-Qing For  Pierre-Olivier Quirion 《Astrophysics and Space Science》2004,291(3-4):465-471

We report on the outcome of the first major multi-site campaign on a long-period variable subdwarf B star. The target PG 1627+017 was observed for a total of 334 h during April/May/June 2003 from the lynchpin observatory at Mt. Bigelow, Arizona, with important contributions coming from co-observations at SAAO, Calar Alto and Siding Spring. Preliminary analysis indicates the presence of 8–10 probable periods in the range ～4500 to ～8900 s with relative amplitudes between 0.1 and 0.5%;. The range over which the periods are found is in qualitative agreement with theoretical predictions and the number of periods found shows potential for an in-depth asteroseismological analysis. Multi-colour observations show that the relative amplitudes of pulsation are larger in the U-band than in the R, which again is in agreement with theory. However, more multi-colour observations are needed to be able to make statements at the quantitative level.  相似文献