Showing papers by "Geophysical Survey published in 2020"

Seismicity of the Erguna Region (Northeastern China): Evidence for Local Stress Redistribution

Abstract: We consider the seismicity of the Erguna region in northeast China (48°–51° N, 117°–123° E) which is poorly studied from seismological point of view as it is characterized by a low level of seismic activity. We calculate focal parameters (focal mechanisms, scalar seismic moments, moment magnitudes, and hypocentral depths) for seven regional earthquakes with Mw 4.2–4.6 that occurred in 2000–2017 using global seismic data of Rayleigh- and Love-wave amplitude spectra and P-wave first-motion polarities recorded at regional stations. It has been shown that the study earthquakes are of small magnitudes (Mw 4.2–4.6), of various hypocentral depths (3–37 km), and are characterized by different kinematics in their sources (normal and thrust faults, strike slips). The different faulting mechanisms could reflect local stress redistribution in small-scale crustal blocks bordered by local short-length nonconnecting faults. The available geophysical and geological data evidence that the observed features of the seismic process in the Erguna region—low-seismic activity and inhomogeneity of the stress-strain field—are likely to be controlled by the structure of the crust and the upper mantle.

Hysteretic Converters with Stochastic Parameters

Abstract: A new class of models of hysteretic converters, generalizing the classical backlash definition to the case where the curves defining it are non-deterministic and have a random distribution, is proposed. In this case, the output of the stochastic converter is defined as a random process. The correctness of the definition of the corresponding converter in terms of a special limit construction is proved. Using such a definition, we can determine the output at an arbitrary continuous input. The properties of the introduced converters are investigated and explicit analytic relations determining the first and second moment (as functions of the corresponding parameters) are presented together with illustrative examples.

Статистические характеристики решений системы стохастической модели переноса

Abstract: Предлагается стохастическая модель переноса, формализуемая с помощью дифференциальных уравнений со случайными параметрами. Получены явные выражения для математического ожидания и второй моментной функции решения соответствующих уравнений. Определена оценка степени влияния случайных факторов на систему в случае замены случайного коэффициента уравнения его математическим ожиданием. Приведен пример, демонстрирующий эффективность предлагаемого подхода в случае гауссова распределения случайных коэффициентов, позволяющий определить математическое ожидание и вторую моментную функцию в рамках модельных представлений. В качестве приложения рассматривается модель переноса тепла и влаги в приземном слое атмосферы.

The influence analysis of reflectance anisotropy of canopy on the prediction accuracy of Cu stress based on laboratory multi-directional measurement

Abstract: The atmosphere calibrated airborne and space borne hyperspectral images are the HDRF of canopy. The spatial nonuniformity of HDRF may result in inversion errors of the heavy metal stressing. In this paper, the HDRF of copper stressed plant samples under different illumination conditions was acquired with the laboratory hyperspectral simulation system called MHRS2F. The difference between the HDRF of canopy and the BCRF of leaves was firstly discussed. Then the changes of spatial distribution of the HDRF for different copper concentrations and illumination conditions were discussed. At last, the sensitivity of various vegetation indices to illumination and observation directions was compared. By comparing the prediction accuracy of different vegetation indices on different observation directions and illumination conditions, the HVI and mRENDVI were found to be more stable and accurate.

Apparatus for Measuring Wideband Dielectric Measurements of Objects Using a Bistatic Antenna

Abstract: A device implementing antennas transmitting and receiving electromagnetic waves for measuring the bulk dielectric properties of a material under test having over a pre-defined surface area. The sample of the material under test might be cylindrical in shape. The device includes a spacer of known dielectric properties and geometries, placed between the material under test and the transmitting and receiving antennas, as well as at least one plate of a material having known electromagnetic properties placed below the material under test.

Mud Volcanoes and Human Geoscience

Abstract: Mud volcanoes are topographic mounts generated by eruption materials that have risen from deep underground because of abnormal groundwater pressure resulting from the dehydration of clay minerals. The activity of the Lusi mud volcano in Indonesia in 2006 caused serious damage to infrastructure and loss of life. Therefore, understanding the activity of mud volcanoes and the relationship between the geological conditions and the location, timing, and mode of mud volcanism is important. Geological, geochemical, and geophysical studies on mud volcanoes in Japan and Taiwan have shown that the location of mud volcanism, the mode of activity, and the rise of highly saline groundwater are strongly affected by geological structures. In this chapter, we describe onshore mud volcanoes in Japan and Taiwan, and give an overview of mud volcanoes and mud volcanism. We then discuss the effects of mud volcanism on human life and the natural environment and note that mud volcanoes and their relationship to underground geological structures should be considered when siting and assessing critical infrastructure.

Discussion on the Application of UAV Oblique Photography in the Registration of Rural Housing and Real Estate Integration

Abstract: At present, the project of rural real estate integration right registration is being launched in many provinces and cities in China. There are three main surveying and mapping methods of real estate integration right registration: full field survey, traditional photogrammetry and Oblique Photography. This paper compared the advantages and disadvantages of the three methods, described the basic principle, key technology and operation process of oblique photography, made comparative analysis on the layout scheme and accuracy of image control points used in real estate integrattion right registration, and put forward an operation scheme which can not only meet the accuracy requirements of surveying and mapping, but also take the efficiency and costs into account.