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1.
Geomagnetism and Aeronomy - Additional horizontal traces of ground reflections were observed in a studied series of high-latitude, Kp sounding ionograms from the Interkosmos-19 satellite. The... 相似文献
2.
Motovilov Yu. G. Golosov S. D. Datsenko Yu. S. Zverev I. S. Puklakov V. V. Fashchevskaya T. B. 《Water Resources》2020,47(5):751-762
Water Resources - An Information–Modeling Complex has been developed for the information support of managerial decision making in the field of rational use, protection, and restoration of... 相似文献
3.
S. Akkar T. Azak T. Çan U. Çeken M. B. Demircioğlu Tümsa T. Y. Duman M. Erdik S. Ergintav F. T. Kadirioğlu D. Kalafat Ö. Kale R. F. Kartal K. Kekovalı T. Kılıç S. Özalp S. Altuncu Poyraz K. Şeşetyan S. Tekin A. Yakut M. T. Yılmaz M. S. Yücemen Ö. Zülfikar 《Bulletin of Earthquake Engineering》2018,16(8):3197-3228
A review on the historical evolution of seismic hazard maps in Turkey is followed by summarizing the important aspects of the updated national probabilistic seismic hazard maps. Comparisons with the predecessor probabilistic seismic hazard maps as well as the implications on the national design codes conclude the paper. 相似文献
4.
5.
Ruth M. K. Plets S. Louise Callard J. Andrew G. Cooper Joseph T. Kelley Daniel F. Belknap Robin J. Edwards Antony J. Long Rory J. Quinn Derek W. T. Jackson 《第四纪科学杂志》2019,34(4-5):285-298
The interplay of eustatic and isostatic factors causes complex relative sea‐level (RSL) histories, particularly in paraglacial settings. In this context the past record of RSL is important in understanding ice‐sheet history, earth rheology and resulting glacio‐isostatic adjustment. Field data to develop sea‐level reconstructions are often limited to shallow depths and uncertainty exists as to the veracity of modelled sea‐level curves. We use seismic stratigraphy, 39 vibrocores and 26 radiocarbon dates to investigate the deglacial history of Belfast Lough, Northern Ireland, and reconstruct past RSL. A typical sequence of till, glacimarine and Holocene sediments is preserved. Two sea‐level lowstands (both max. ?40 m) are recorded at c. 13.5 and 11.5k cal a bp . Each is followed by a rapid transgression and subsequent periods of RSL stability. The first transgression coincides temporally with a late stage of Meltwater Pulse 1a and the RSL stability occurred between c. 13.0 and c. 12.2k cal a bp (Younger Dryas). The second still/slowstand occurred between c. 10.3 and c. 11.5k cal a bp . Our data provide constraints on the direction and timing of RSL change during deglaciation. Application of the Depth of Closure concept adds an error term to sea‐level reconstructions based on seismic stratigraphic reconstructions. 相似文献
6.
Geomagnetism and Aeronomy - The paper presents the results of a study of microwave thermal bremsstrahlung of local sources above sunspots. Special attention is paid to the transition from thermal... 相似文献
7.
Fernando Coreixas de Moraes Fernanda Cervi Cludia S. Karez Leonardo T. Salgado Rodrigo L. Moura Gabriella A. Leal Alex C. Bastos Gilberto M. Amado‐Filho 《Marine Ecology》2019,40(3)
Bioeroding sponges belong to the most dominant bioeroders, significantly contributing to the erosion of coral reefs. Some species are tolerant or even benefit from environmental conditions such as ocean warming, acidification, and eutrophication. In consequence, increases in sponge bioerosion have been observed on some coral reefs over the last decades. The Abrolhos Bank is the largest coral reef system in the South Atlantic. It has been affected by sedimentation, eutrophication, overfishing, and climate change, mainly affecting coastal reefs, and at lesser intensity outer ones as well. This study aimed to describe spatial and temporal patterns in bioeroding sponge distribution in carbonate substrates in the Abrolhos Bank. Photo‐quadrats were used to compare bioeroding sponge abundance between two shallow reefs: a coastal, Pedra de Leste (PL), and an outer reef, Parcel dos Abrolhos (PAB). Each individual was delimitated over the substrate by determining the sponge surface through a line connecting the outermost papillae. The study was conducted over 6 years in 2008–2009 and 2013–2016. Four species of bioeroding sponges were identified: Cliona carteri Ridley, 1881, C. delitrix Pang, 1973, C. cf. schmidtii Ridley, 1881, and Siphonodictyon coralliphagum Rützler, 1971. The distribution and abundance of species varied between the inner and outer reefs and across the years, and displayed certain selectivity for the calcareous substrates recorded. Crustose coralline algae (CCA) were the main substrate excavated by the most abundant bioeroding species, C. carteri, and represented 70% of the substrate types occupied by this sponge (CCA, coral overgrown by CCA and plain coral). The highest abundance of bioeroding sponges observed in photo‐quadrats was 21.3 individuals/m2 at the outer reefs (PAB) in 2014. The abundances or areal extents of bioeroding sponges were up to 10 times greater on the outer reefs than on the coastal ones, where sedimentation is higher and more strongly influenced by siliciclastic material. Moreover, a higher herbivorous fish biomass has been reported on outer reefs which could also influence the higher abundance of bioeroding sponges in outer reefs. During the study period of 6 years, an increase in bioeroding sponge abundance was observed at the outer reefs (PAB), with the sea surface temperature increase. As CCA have an important role in reefal cementation and carbonate production in the Abrolhos reefs, a bioerosion impact might be expected, in particular, on the outer reefs. 相似文献
8.
Geomagnetism and Aeronomy - Measurements of the differential fluxes of energetic electrons in the equatorial region of the magnetosphere in the energy range from units of keV to hundreds of keV... 相似文献
9.
Tsap Yu. T. Stepanov A. V. Kopylova Yu. G. Khaneichuk O. V. 《Geomagnetism and Aeronomy》2020,60(4):446-451
Geomagnetism and Aeronomy - The propagation of linear Alfvén waves with periods of 10–200 s from the photosphere to the solar chromosphere under the conditions of an isothermal... 相似文献
10.
Matt T. Trentman Jennifer L. Tank Todd V. Royer Shannon L. Speir Ursula H. Mahl Lienne R. Sethna 《水文研究》2020,34(23):4446-4458
Subsurface tile drainage speeds water removal from agricultural fields that are historically prone to flooding. While managed drainage systems improve crop yields, they can also contribute tothe eutrophication of downstream ecosystems, as tile-drained systems are conduits for nutrients to adjacent waterways. The changing climate of the Midwestern US has already altered precipitation regimes which will likely continue into the future, with unknown effects on tile drain water and nutrient loss to waterways. Adding vegetative cover (i.e., as winter cover crops) is one approach that can retain water and nutrients on fields to minimize export via tile drains. In the current study, we evaluate the effect of cover crops on tile drain discharge and soluble reactive phosphorus (SRP) loads using bi-monthly measurements from 43 unique tile outlets draining fields with or without cover crops in two watersheds in northern Indiana. Using four water years of data (n = 844 measurements), we examined the role of short-term antecedent precipitation conditions and variation in soil biogeochemistry in mediating the effect of cover crops on tile drain flow and SRP loads. We observed significant effects of cover crops on both tile drain discharge and SRP loads, but these results were season and watershed specific. Cover crop effects were identified only in spring, where their presence reduced tile drain discharge in both watersheds and SRP loads in one watershed. Varying effects on SRP loads between watersheds were attributed to different soil biogeochemical characteristics, where soils with lower bioavailable P and higher P sorption capacity were less likely to have a cover crop effect. Antecedent precipitation was important in spring, and cover crop differences were still evident during periods of wet and dry antecedent precipitation conditions. Overall, we show that cover crops have the potential to significantly decrease spring tile drain P export, and these effects are resilient to a wide range of precipitation conditions. 相似文献