Natural Hazards - One of the most important aspects in tsunami studies is the behaviour of the wave when it approaches the coast. Information on physical parameters that characterize waves is often... 相似文献
Natural Resources Research - Recognition of reservoir quality is an important objective in reservoir characterization process. By definition, the quality of a reservoir is described by its... 相似文献
Geomagnetism and Aeronomy - The paper quantitatively compares the results of calculations of the electron density Ne by the International Reference Ionosphere model IRI-2016 with experimental data... 相似文献
Natural Hazards - The investigation of earthquake recurrence networks that were constructed from two aftershock sequences in Greece, is performed, aiming to detect whether the structure of networks... 相似文献
Oceanology - Abstract—The paper contains original data on the rock-forming and rare element compositions in the Pliocene–Holocene alkaline basaltoids of the Tsushima Basin Sea of Japan,... 相似文献
Thanks to the pioneering research of Paul Younger over the past 20 years, acid mine drainage in the UK has been recognized as a major environmental issue. Acid mine drainage and hydrous ferric oxide deposition are environmental hazards resulting from centuries of extensive coal mining activities across the UK. Oxidative weathering of pyrite in coal from spoil heaps and exposed bedrock can liberate trace elements, releasing them into local water systems. In addition to posing an environmental threat through water and ground contamination, ochres can also act as a remediation material, trapping elements such as selenium. Trace elements with a close association to iron oxides, such as selenium, may fix to the fine‐grained ochre materials, resulting in hyper‐enriched ochres. Selenium in coals has been known to cause an environmental issue in areas of North America but is also an important commodity for solar cells and nanotechnologies. Coal‐bearing areas of the UK, such as Northumberland, are known to contain a high selenium content, and coal‐derived ochres in these regions also contain significant selenium. The widespread occurrence of ochres in UK coal‐mining regions may therefore present a unique ‘E tech’ trace element source and prevent a toxicity problem for which they were once thought to be responsible. 相似文献
Planetary bodies a few hundred kilometers in radii are the precursors to larger planets but it is unclear whether these bodies themselves formed very rapidly or accreted slowly over several millions of years. Ordinary H chondrite meteorites provide an opportunity to investigate the accretion time scale of a small planetary body given that variable degrees of thermal metamorphism present in H chondrites provide a proxy for their stratigraphic depth and, therefore, relative accretion times. We exploit this feature to search for nucleosynthetic isotope variability of 54Cr, which is a sensitive tracer of spatial and temporal variations in the protoplanetary disk's solids, between 17 H chondrites covering all petrologic types to obtain clues about the parent body accretionary rate. We find no systematic variability in the mass‐biased corrected abundances of 53Cr or 54Cr outside of the analytical uncertainties, suggesting very rapid accretion of the H chondrite parent body consistent with turbulent accretion. By utilizing the μ54Cr–planetary mass relationship observed between inner solar system planetary bodies, we calculate that the H chondrite accretion occurred at 1.1 ± 0.4 or 1.8 ± 0.2 Myr after the formation of calcium‐aluminum‐rich inclusions (CAIs), assuming either the initial 26Al/27Al abundance of inner solar system solids determined from angrite meteorites or CAIs from CV chondrites, respectively. Notably, these ages are in agreement with age estimates based on the parent bodies’ thermal evolution when correcting these calculations to the same initial 26Al/27Al abundance, reinforcing the idea of a secular evolution in the isotopic composition of inner disk solids. 相似文献
The LP/OMPS limb sensor of the Suomi satellite detected the atmospheric trace of the Chelyabinsk superbolide with an energy of over 400 kt TNT in 2013. The study of LP/OMPS data shows that it detects several bolides with much less energy each year. The paper considers the cases of observation of three bolides in 2016–2017: on February 6, 2016 (13 kt), March 3, 2016 (0.19 kt), and March 9, 2017 (1 kt). The possibility of improving the detection of bolides using a limb sensor in the form of a microsatellite with an increased number of observation regions along the horizon is discussed. Several such microsatellites will be able to track most of the bodies larger than a meter that burn up in the atmosphere of the Earth or Mars.
At the present time, there is no generally accepted classification of the solar wind flows. There are various approaches to this problem depending on the goal of the study. In our paper, we propose the binary classification of the solar wind types by the main hydrodynamic parameters (velocity, temperature, and density) based on the statistical analysis of the solar wind. The analysis of the OMNIWeb one-minute data is performed for the period from 1996 to 2017, which encompasses solar cycle 23 and current solar cycle 24. Eight types of the solar wind are distinguished: fast-hot-dense, fast-hot-rarefied, fast-cold-dense, fast-cold-rarefied, slow-hot-dense, slow-hot-rarefied, slow-cold-dense, slow-cold-rarefied. These types occur with different frequency and are the consequences of different manifestations of solar activity. Of particular interest are the solar wind flows, the parameters of which deviate from the averages most significantly.
