Revised recommended methods for analyzing crater size-frequency distributions          下载免费PDF全文

Stuart J. Robbins  Jamie D. Riggs  Brian P. Weaver  Edward B. Bierhaus  Clark R. Chapman  Michelle R. Kirchoff  Kelsi N. Singer  Lisa R. Gaddis 《Meteoritics & planetary science》2018,53(4):891-931

Impact crater populations help us to understand solar system dynamics, planetary surface histories, and surface modification processes. A single previous effort to standardize how crater data are displayed in graphs, tables, and archives was in a 1978 NASA report by the Crater Analysis Techniques Working Group, published in 1979 in Icarus. The report had a significant lasting effect, but later decades brought major advances in statistical and computer sciences while the crater field has remained fairly stagnant. In this new work, we revisit the fundamental techniques for displaying and analyzing crater population data and demonstrate better statistical methods that can be used. Specifically, we address (1) how crater size-frequency distributions (SFDs) are constructed, (2) how error bars are assigned to SFDs, and (3) how SFDs are fit to power-laws and other models. We show how the new methods yield results similar to those of previous techniques in that the SFDs have familiar shapes but better account for multiple sources of uncertainty. We also recommend graphic, display, and archiving methods that reflect computers’ capabilities and fulfill NASA's current requirements for Data Management Plans.  相似文献   

Seismic electric signals in seismic prone areas          下载免费PDF全文

Nicholas V.Sarlis  Panayiotis A.Varotsos  Efthimios S.Skordas  Seiya Uyeda  Jacques Zlotnicki  Toshiyasu Nagao  Anatoly Rybin  Mary S.Lazaridou-Varotsos  Konstantina A.Papadopoulou 《地震科学（英文版）》2018,31(1):44-51

The Varotsos-Alexopoulos-Nomicos(VAN) method of short-term earthquake prediction was introduced in the 1980s. The VAN method enables estimation of the epicenter, magnitude and occurrence time of an impending earthquake by observing transient changes of the electric field of the Earth termed seismic electric signals(SES). Here, we present a few examples of SES observed in various earthquake prone areas worldwide.  相似文献   

Irregular Phenomena in Magnetically Conjugate Regions of the <Emphasis Type="Italic">F</Emphasis>2 Layer of the Ionosphere     

N. P. Sergeenko 《Geomagnetism and Aeronomy》2018,58(6):823-830

  相似文献   

Planetary Wave Periods in <Emphasis Type="Italic">foF</Emphasis>2 Time Variations Based on Winter Data from Kaliningrad Station in 2008−2010     

Yu. N. Koren’kov  F. S. Bessarab  N. A. Koren’kova  V. S. Leshchenko 《Geomagnetism and Aeronomy》2018,58(3):420-429

The study presents the results of the analysis of the F2-layer critical frequency variations obtained for the winter periods of 2008–2010, during which sudden stratospheric warmings were observed. The data were obtained at Kaliningrad ionospheric station (54.6° N, 20° E) with the Parus digital ionosonde in standard sounding mode. The mean daily foF2 values were used in the analysis. The results of spectral analysis based on continuous wavelet transform showed that, during all of the warmings that occurred in 2008–2010, the foF2 time variations demonstrated the presence of wave processes with periods of approximately 5?6 days, as well as more extended processes with periods of ~10?13 and 23?30 days. These periods coincide with the characteristic periods of planetary waves observed in the mesosphere during sudden stratospheric warmings, while the 13- and 30-day periods can be conditioned by the influence of the Sun.  相似文献   

Effect of Electron Precipitations on the Effective Recombination Coefficient     

Zh.?V.?DashkevichEmail author  V.?E.?Ivanov 《Geomagnetism and Aeronomy》2018,58(2):290-293

The results of an analysis of the possible effect of auroral electron fluxes on the effective recombination coefficient α_eff in the ionosphere are presented. It is shown that the α_eff value in the E-region of the ionosphere is determined mainly by the physical-chemical properties of the medium. In the F1-layer of the ionosphere, the effective recombination coefficient becomes dependent on both the value of the energy flux and the type of the energy spectrum of the auroral electron flux.  相似文献   

Spatial and Temporal Variations of Infrared Emissions in the Upper Atmosphere. 3. 5.3-μm Nitric Oxide Emission     

A.?I.?SemenovEmail author  I.?V.?Medvedeva  V.?I.?Perminov 《Geomagnetism and Aeronomy》2018,58(2):273-280

The results of rocket and satellite measurements available in the literature of 5.3-μm nitric oxide emission in the upper atmosphere have been systematized and analyzed. Analytical dependences describing the height distribution of volumetric intensity of 5.3-μm emission of the NO molecule and its variations in a range of heights from 100 to 130 km as a function of the time of year, day, latitude, and solar activity have been obtained.  相似文献   

Effect of Bank Deformations on Pollutant Transport in Rivers in Cryolithozone: Laboratory and Mathematical Modeling     

E. I. Debol’skaya  I. I. Gritsuk  V. K. Debol’skii  D. N. Ionov  O. Ya. Maslikova 《Water Resources》2018,45(4):542-552

The study is focused on pollution transport in rivers flowing in cryolithozone and takes into account possible channel deformations caused by thawing of permafrost rocks in which the channel runs. The methods used are laboratory and mathematical modeling. The mathematical model consists of four blocks: hydrodynamic, thermal, deformation, and pollutant transport. The model was validated and tested against the data of a laboratory experiment. Numerical experiments suggested conclusions regarding the propagation of pollutants entering the flow from sources in thawing bank slopes and on river floodplain.  相似文献   

The Present-Day Hydrochemical State of Hydroecosystems Suffering the Technogenic Effect of AO Apatit     

M. A. Chukaeva  V. A. Matveeva 《Water Resources》2018,45(6):935-940

Hydrochemical studies have been carried out to assess the extent of molybdenum and aluminum pollution of wastewaters from Apatit plant and natural water bodies suffering higher technogenic load. The main sources of surface water pollution by aluminum and molybdenum have been identified. The interrelationship between the natural and technogenic factors at the formation of aluminum- and molybdenum-containing wastewaters as well as quarry and mine waters has been studied.  相似文献   

Method for Constructing a Model of a Geoelectric Section Taking into Account Seasonal Variations Based on Data from Long-Term Vertical Electric Sounding Monitoring in Search of Earthquake Precursors     

A. V. Desherevskii  I. N. Modin  A. Ya. Sidorin 《Seismic Instruments》2018,54(4):424-436

The study analyzes data from high-precision measurements of the apparent resistivity by a stationary multielectrode vertical electric sounding (VES) system including 12 current and 4 potential lines spaced 2–650 m apart. Observations had been being carried out at the Garm test area on a daily basis for 12 years in an earthquake prediction experiment. The use of special technical methods during measurements ensured an instrumental error of about 0.01%. The virtual error of each individual measurement of apparent resistivity (taking into account all possible noise) was 0.1–0.2%. The availability of more than 3000 VES curves measured in different seasons allows us to propose a new approach to constructing a geoelectric section model. To solve the inverse VES problem, a set of 36 averaged 10-day VES curves was analyzed, each of which was obtained by averaging approximately 100 individual VES curves accumulated in the same 10-day period of the annual (seasonal) cycle in different years. Comparative analysis of these curves made it possible to calculate and include corrections for stationary geological noise in the model. As a result, it was possible to substantially reduce (by an order of magnitude) the discrepancies in fitting the curves and dramatically narrow the equivalence domain. Based on the results of our analysis, we have constructed a model of a four-layer horizontally layered geoelectric section of the Khazor-Chashma depression to adequately describe not only the averaged section, but also its seasonal variations throughout the year. The stability in estimating the model parameters is studied. To further reduce the equivalence domain, we propose that the layer thicknesses be fixed. This model can be used not only to study the aforementioned characteristics of the section, but also to monitor time variations of resistivity in individual layers of the section. This will significantly improve the resolving power of systems for detecting time variations in geoelectric sections, including when searching for earthquake precursors.  相似文献   

Prevention of Shield-Induced Desynchronosis in Invertebrates by a Variable Magnetic Field of Extremely Low Frequency     

N. A. Temuryants  K. N. Tumanyants  A. S. Kostyuk  N. S. Yarmolyuk  E. N. Tumanyants 《Izvestiya Atmospheric and Oceanic Physics》2018,54(7):661-666

  相似文献