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Published and new data on the Earth’s past magnetic field have been interpreted in terms of its links with the frequency of magnetic polarity reversals and with tectonic events such as plume-related eruptions and rifting. The paleointensity and reversal frequency variations show an antiphase correlation between 0 and 160 Ma, and the same tendency likely holds for the past 400 Myr. The geomagnetic field intensity averaged over geological ages (stages) appears to evolve in a linearly increasing trend while its variations increase proportionally in amplitude and change in structure. Both paleointensity and reversal frequency patterns correlate with rifting and eruption events. In periods of high rifting activity, the geomagnetic field increases (15 to 30%) and the reversals become about 40% less frequent. Large eruption events between 0 and 150 Ma have been preceded by notable changes in magnetic intensity which decreases and then increases, the lead being most often within a few million years.  相似文献   
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Physical properties of cores taken from sediments in the channel zone of the Volga Stretch in the Rybinsk Reservoir are studied. The physical properties of the sediments are shown to be related to the evolution of geomorphological processes and the amount of organic matter in the sediment. Variations in the physical properties were used to recognize synchronous formation of sediment horizons corresponding to certain formation stages of the reservoir soil complex and anomalous environmental and climatic events. Three stages of channel sedimentation are established based on characteristic behavior of magnetic parameters and organic matter content. The magnetic parameters of sediments are shown to allow data reconstruction on some environmental and hydrological processes.  相似文献   
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This study provides a compilation of the paleointensity records for the Cretaceous period derived from sediments of the Russian Plate and adjacent areas. The paleoinetensity values were calibrated using the laboratory redeposition experiments. Remarkable differences in the relative paleointensity variations were detected at the Berriasian–Early Barremian, Late Barremian–Santonian and Early–Late Maastrichtian boundaries. In the Berriasian–Early Barremian interval, the paleointensity varied stochastically, with the amplitude of about 1Ho and the mean value of 0.63Ho (Ho is the present-day geomagnetic field intensity assumed to be 40 μT). The records for the Barremian–Santonian give a picture of the geomagnetic field with alternating high- and low-amplitude features. The mean paleointensities remain constantly high (being on average 0.87Ho), and intervals of low-amplitude variation alternate with the pronounced bursts (3.5Ho). The Late Maastrichtian interval is characterized by high-amplitude paleointensity variations (4Ho) and a sharp drop towards the end of the interval. All records show remarkable similarities near the boundaries between geological time intervals, which are an increase in the amplitude and mean values of intensity at the end of intervals followed by a decrease towards the beginning of the subsequent interval.  相似文献   
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The results of comparative analysis of the behavior of paleointensity and polarity (intervals between reversals) of the geomagnetic field for the last 167 Ma are presented. Similarities and differences in the behavior of these characteristics of the geomagnetic field are discussed. It is shown that bursts of paleointensity and long intervals between reversals occurred at high mean values of paleointensity in the Cretaceous and Paleogene. However, there are differences between the paleointensity behavior and the reversal regime: (1) the characteristic times of paleointensity variations are less than the characteristic times of the frequency of geomagnetic reversals, (2) the achievement of maximum values of paleointensity at the Cretaceous–Paleogene boundary and the termination of paleointensity bursts after the boundary of 45–40 Ma are not marked by explicit features in the geomagnetic polarity behavior.  相似文献   
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Izvestiya, Physics of the Solid Earth - Peat cores sampled from different climatic zones are studied. The petromagnetic and microprobe methods are used to find peat layers enriched with cosmic...  相似文献   
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The paper generalizes results of study of the intermittency pattern in some wave processes of the burst type in the high-latitude magnetosphere of the Earth. Based on the analysis of distributions of amplitudes and interpeak intervals, it is shown that generation regimes of magnetic impulse events, ipclpulsation burst series, and Pi3 pulsations possess the properties of intermittent processes and are associated with the development of plasma turbulence in their generation regions. The degree of turbulence of the high-latitude magnetosphere plasma is estimated at a qualitative level. Burst-type structures whose behavior corresponds to a typical intermittent process are discovered in variations of the ancient geomagnetic field.  相似文献   
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Geomagnetism and Aeronomy - Regularities in the distribution of extreme (burst) increases in paleointensities from 3000 Ma to the present have been studied. Paleointensity bursts that exceed...  相似文献   
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