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991.
MONTA?EZ P. Isabel HU Xiumian HOU Mingcai WANG Chengshan CHEN Jitao DDE Sedimentology Palaeogeography Groups 《《地质学报》英文版》2019,93(Z1):52-54
正1 Introduction Sedimentary rocks archive important information for understanding how the earth system operates and how life and environments have evolved through earth history.Properly identifying characteristics of sedimentary rocks,along with the subsequent interpretation of depositional processes and sedimentary environments in a basin or locality,are fundamental to inter-basinal correlation of sedimentary successions as well as to understanding and deconvolving regional and global processes 相似文献
992.
Mathematical Geosciences - Customary and routine practice of geostatistical modeling assumes that inter-point distances are a Euclidean metric (i.e., as the crow flies) when characterizing spatial... 相似文献
993.
994.
Isabelle Coutand Michael Walsh Bertha Louis Frank Chanier Jacky Ferrière Jean‐Yves Reynaud 《地学学报》2014,26(4):287-297
The North Anatolian Fault Zone (NAFZ) is one of the most hazardous active faults on Earth, yet its Pliocene space‐time propagation across the north Aegean domain remains poorly constrained. We use low‐temperature multi‐thermochronology and inverse thermal modelling to quantify the cooling history of the upper crust across the Olympus range. This range is located in the footwall of a system of normal faults traditionally interpreted as resulting from superposed Middle–Late Miocene N–S stretching, related to the back‐arc extension of the Hellenic subduction zone, and a Pliocene‐Quaternary transtensional field, attributed to the south‐westward propagation of the NAFZ. We find that accelerated exhumational cooling occurred between 12 and 6 Ma at rates of 15–35 °C Ma?1 and decreased to <3 °C Ma?1 by 8–6 Ma. The absence of significant Plio‐Pleistocene cooling across Olympus suggests that crustal exhumation there is driven by late Miocene back‐arc extension, while the impact of the NAFZ remains limited. 相似文献
995.
Susanne Glaser Rolf König Dimitrios Ampatzidis Tobias Nilsson Robert Heinkelmann Frank Flechtner Harald Schuh 《Journal of Geodesy》2017,91(7):723-733
In this study, we assess the impact of two combination strategies, namely local ties (LT) and global ties (GT), on the datum realization of Global Terrestrial Reference Frames in view of the Global Geodetic Observing System requiring 1 mm-accuracy. Simulated Very Long Baseline Interferometry (VLBI) and Satellite Laser Ranging (SLR) data over a 7 year time span was used. The LT results show that the geodetic datum can be best transferred if the precision of the LT is at least 1 mm. Investigating different numbers of LT, the lack of co-located sites on the southern hemisphere is evidenced by differences of 9 mm in translation and rotation compared to the solution using all available LT. For the GT, the combination applying all Earth rotation parameters (ERP), such as pole coordinates and UT1-UTC, indicates that the rotation around the Z axis cannot be adequately transferred from VLBI to SLR within the combination. Applying exclusively the pole coordinates as GT, we show that the datum can be transferred with mm-accuracy within the combination. Furthermore, adding artificial stations in Tahiti and Nigeria to the current VLBI network results in an improvement in station positions by 13 and 12%, respectively, and in ERP by 17 and 11%, respectively. Extending to every day VLBI observations leads to 65% better ERP estimates compared to usual twice-weekly VLBI observations. 相似文献
996.
B.?ForesEmail authorView authors OrcID profile C.?Champollion N.?Le?Moigne J.?Chery 《Journal of Geodesy》2017,91(3):269-277
In this paper, we investigate the impact of ambient temperature changes on the gravity reading of spring-based relative gravimeters. Controlled heating experiments using two Scintrex CG5 gravimeters allowed us to determine a linear correlation (R \(^{2}>\) 0.9) between ambient temperature and gravity variations. The relation is stable and constant for the two CG5 we used: ?5 nm/s\(^{2}/^\circ \)C. A linear relation is also seen between gravity and residual sensor temperature variations (R \(^{2}>\) 0.75), but contrary to ambient temperature, this relation is neither constant over time nor similar between the two instruments. The linear correction of ambient temperature on the controlled heating time series reduced the standard deviation at least by a factor of 2, to less than 10 nm/s\(^{2}\). The laboratory results allowed for reprocessing the data gathered on a field survey that originally aimed to characterize local hydrological heterogeneities on a karstic area. The correction of two years of monthly CG5 measurements from ambient temperature variations halved the standard deviation (from 62 to 32 nm/s\(^{2}\)) and led us to a better hydrological interpretation. Although the origin of this effect is uncertain, we suggest that an imperfect control of the sensor temperature may be involved, as well as a change of the properties of an electronic component. 相似文献
997.
Spatial variability in the chemical composition of the snowcover at high alpine sites 总被引:1,自引:0,他引:1
W. Schöner H. Puxbaum M. Staudinger F. Maupetit D. Wagenbach 《Theoretical and Applied Climatology》1997,56(1-2):25-32
Summary For a comparison of snow chemistry data from different glaciers or snow fields it is important to have informations about the spatial representativeness of the data from each of the individual sites. In order to assess the representativeness of concentration data of major ions (volume weighted means of the winter accumulation) from glacier fields we investigated the variability in the average concentration of major ions from parallel samples within one snow pit and from different pits within one glacier field. The variabilities in the average concentrations of NO
3
-
, SO
4
2-
and NH
4
+
for three parallel profiles within one snow pit at Goldbergkees (Austria) were 1.2, 3.3 and 2.0% (coefficient of variation). Cl– and Na+ showed larger variations (6.6 and 56.6%) possibly originating from contaminations. The variability of average concentration data from different snow pits within one glacier field was studied at La Grave (France) and at Goldbergkees (Austria). At La Grave 3 pits and at Goldbergkees 4 pits at distance of several hundred meters were sampled. Variabilities for SO
4
2-
and NO
3
-
were quite similar for the two sites (17% for both ions at La Grave, 12% and 15% at Goldbergkees). Whereas variabilities for Na+, NH
4
+
, Mg2+, Ca2+ and Cl– were quite low at La Grave ( 12% and 27% for Cl–), higher values were obtained at Goldbergkees for these ions (17–56%). Likely reasons for the higher variability observed at Goldbergkees are a) higher spatial variability of crustal aerosol species (Mg2+, Ca2+), b) problems with the detection limit of the analytical method (Ca2+), c) contaminations (Na+, Cl–).With 4 Figures 相似文献
998.
999.
G. A. Rune et T. J. Kukkam?ki 《Journal of Geodesy》1951,25(4):447-457
Conclusion Au total, les travaux de la Section des Nivellements, à Bruxelles, où s’exerce l’art des nivellements, un véritable bouillonnement
d’idées, hatant la solution de problèmes anciens, rénovant leur aspect, suscitant maintes tentative et réalisations inédites. 相似文献
1000.
Dr. med G. Huber-Pestalozzi Hans Wolfgang Schäfer 《Aquatic Sciences - Research Across Boundaries》1951,13(1):192-196
Ohne Zusammenfassung 相似文献