Study Of Recent Crustal Movements Research Articles

DEVELOPMENT OF A SERVICE ORIENTED ARCHITECTURE BASED GEOGRAPHIC INFORMATION SYSTEM IN EARTH SCIENCES

Abstract. The studies of recent crustal movements are based on analyses of repeated geodetic measurements, and their combination with results of geophysical and geological investigations. It is obvious that a single data producer can not produce useful datasets and information without integrating data from others because one scientist’s results become another’s data. So, the problem to be solved naturally has an interdisciplinary character. However, Earth scientists traditionally work on one aspect of the problem and they have a tradition of sharing of data but they are willing to share it if asked. Because of this, the resources are being wasted in duplicative efforts. However, the goal is for data to evolve it into information, and then into knowledge as quickly and effectively as possible. In order to do this, calculations and analysis need to bring to the desktops of researchers, decision-makers, and educators. The aim of this study is to develop a service-oriented architecture (SOA) based Geographic Information System (GIS) that enables linking and sharing multidisciplinary Earth science data, tools, and software and to provide a wide range of users access to the system and in this way to build an easy-to-use interactive access to data and analysis environment to study earthquakes in Turkey.

Study of recent crustal movements in Romania (Gruiu-Caldamsani polygon)

Repeated levelling and gravity measurements have been carried out in the Romanian Gruiu-Căldăruşani geodynamic polygon. The geodetic data showed vertical movements and the influence of the Vrancea earthquakes on the benchmark elevations. La Coste-Romberg gravity meter measurements indicated the gravity differences before and after the Vrancea earthquake of August 30, 1986, effects which were probably due to the microfracturing field in the fine texture of sedimentary rocks.

The study of recent crustal movements from extensometric data

Extensometric observations provide valuable data on recent crustal movements because of the high sensitivity of geophysical instruments and their ability to produce observation series continuous in time. The problem is whether the tectonic component of the movement can be determined from extensometric data. In the present paper an attempt is made to identify tectonic deformations on the basis of observation series of a 20-year period conducted at one of the extensometric stations (Talgar). Preparatory studies are made to find the nature of seasonal variations in the deformation time changes. The correlation of these variations with changes in the amount of atmospheric precipitation, and also the general periodicity in the deformation curve and in the atmospheric precipitation curve, enable us to eliminate the deformation caused by atmospheric precipitation from the deformation curve. The residual deformation curve reveals variations coinciding in time with the periods of higher seismic activity in the region of observations. Harmonics are derived from the deformation curve and their periods coincide with the periods of recurrent local earthquakes of energetic class 13–14.

Study of recent crustal movements on apsheron peninsula by geodetic methods

In active tectonic areas with rapid Recent Vertical Movements of the Earth's Crust (RVMEC), where movements are complicated by their technogenic origin, adjustments of precise geodetic measurements are impossible to carry out using the existing technological diagrams and specified tolerances, due to the fact that the measured parameters have varied in time. This article covers experience in the compositions of the RVMEC map, using the results of three first-order relevellings. Using this map, methods for adjustments of levelling networks and compilations of dynamic cataloques of heights, where field measurements have been updated, have been developed. The RVMEC map is used for geological and geophysical data interpretation in conjunction with results of geodetic measurements. The article gives parameters of abnormal values for vertical movements of separate sites, rates of general subsidence of the southern part of the Apsheron Peninsula and correlations of gravimetric measurement data.

The study of recent crustal movements from extensometric data

Abstract Extensometric observations provide valuable data on recent crustal movements because of the high sensitivity of geophysical instruments and their ability to produce observation series continuous in time. The problem is whether the tectonic component of the movement can be determined from extensometric data. In the present paper an attempt is made to identify tectonic deformations on the basis of observation series of a 20-year period conducted at one of the extensometric stations (Talgar). Preparatory studies are made to find the nature of seasonal variations in the deformation time changes. The correlation of these variations with changes in the amount of atmospheric precipitation, and also the general periodicity in the deformation curve and in the atmospheric precipitation curve, enable us to eliminate the deformation caused by atmospheric precipitation from the deformation curve. The residual deformation curve reveals variations coinciding in time with the periods of higher seismic activity in the region of observations. Harmonics are derived from the deformation curve and their periods coincide with the periods of recurrent local earthquakes of energetic class 13–14.

Toward international cooperation in the study of recent crustal movements in Africa

How might an international plan for crustal-movement studies in Africa be implemented? This was the basic question underlying much of the discussion at the First International Symposium on Crustal Movements in Africa, convened in May 1981 in Addis Ababa at the United Nations Economic Commission for Africa. Three years later, in November/December 1984, the Second Symposium was held in Cairo, Egypt; and in April 1986, some outstanding questions were dealt with at the Third Symposium on Geodesy in Africa held in Yamoussoukro, Ivory Coast, and at the International Symposium on Global Changes in Africa during the Quaternary, held in Dakar, Senegal. The present state and possible development of recent crustal movement studies in Africa are discussed. Finally, the cooperation of all scientists interested in such studies is solicited.

Possibilities for the study of recent crustal movements in the Struma fault zone, on the basis of neotectonic and geodetic data and their relations to earthquakes

Possibilities for the study of recent crustal movements in the Struma fault zone, on the basis of neotectonic and geodetic data and their relations to earthquakes

A criterion matrix for the second order design of control networks

This paper proposes an original method of constructing a criterion matrix for the optimal design of control networks by means of the contraction of the eigenvalues and the rotation of the eigenvectors of a covariance matrix. The rotation of the eigenvectors is carried out by two different methods, that is through independent rotations of the pairs of the eigenvector matrix components and through a procrustean transfomation of the same matrix. The required criterion is that the “essential eigenvector components” must be as orthogonal as possible to the predicted direction of deformation. A Second Order Design problem is then resolved, that is the optimization of the precision of the observations of a local free distance network to be constructed for the study of recent crustal movements in the seismogenetic area of Friuli (Italy). The results obtained show a high degree of correspondence for the two proposed methods of rotation if limited rotations of the eigenvectors are considered.

The concept of goodness of geodetic observations restated in view of the requirements of studies of recent crustal movements

The estimation of recent crustal movements from repeated geodetic observations is somewhat hampered by an apprehension of the uncertainties involved in the estimation of the standard errors of the observations and by the lack of correlation between the actual errors in networks and the theoretical estimates of these errors. It is here shown that a more reliable evaluation of the quality of the observations may be reached through a factor analysis of several statistical parameters. The suggested procedure is tentatively applied to some published data and a scheme aiming at a generalized treatment is proposed.

Interferometric methods for distance measuring in the study of recent crustal movements

In solving a series of problems in the study of recent crustal movements, interferential methods may prove to be more effective than electronic distance measurements or other methods. The interferential methods now in existence have substantial shortcomings impeding their wide used in solving the above problems. The possibilities of the interferometric method based on the employment of the light source with variable coherence time are discussed.

Summary of geodetic studies of recent crustal movements in Switzerland

Vertical movements: the vertical movements of the earth's crust are mainly studied in connection with the repetition of the measurements along the federal levelling traverses. These measurements have made conspicuous the uplift of the crystalline massives in relation to the molassic region. The rate of these vertical movements amounts to about 1 mm/year. Since 1973, studies of vertical movements have been carried out in limited areas (north of Basel, at Andermatt on the junction of the Gotthard- and Aar-massives). A repetition of the measurements is planned for the years 1978–1980. Horizontal movements: combined measurements of distances and directions have been executed in the year 1973 in two test areas of about 400 m × 400 m in the region of the Pontarlier strike-slip fault line in the Jura Mountains. Tests have been executed with the Mekometer ME 3000 (Kern & Co. Ltd., Aarau). The measurements, executed in May 1974, have allowed us to estimate an accuracy of such distances of about ± 1.5 ppm.

Recent crustal movements: Techniques and achievements

A fuller knowledge of the nature and rate of recent crustal movements would do much to relate geomorphology to geology to the benefit of both. The study of recent crustal movements is a diverse one, and extends from structural geology through geomorphology to geodetics. The three fields differ in their techniques, but the all-important difference between them is the interval of time they cover. Tectonic processes are cyclic, with periodicities that are not well known, and cannot be known unless all three fields are covered. The critical periodicity for large-scale mountain building is probably from 0.5 to 10 million years. The period is largely that of geomorphology but the geomorphological part of recent crustal movements is the part least well quantitized. This is partly because the necessary surveys are too time-consuming to appeal to most geologists and too trivial to appeal to most geodesists. Too often geomorphic studies are largely descriptive, and rarely are estimates given of errors in time and distance. An attempt is made in the following account to cover all fields, to relate errors of observations to probable movements, and to give an account of the achievements considered most significant.