Study Of Vertical Movements Research Articles

Monumentations of control points for the measurement of soil vertical movements and their interactions with ground water contents

Historically, one of the techniques used in the study of vertical movements of soil is that of high precision spirit levelling. Nowadays, this technique is often accomplished by satellite interferometric synthetic aperture radar (SAR) analysis that requires a calibration phase, i.e. through the connection to a spirit levelling network or by means of a long time series acquired by global navigation satellite systems permanent stations in order to transform relative velocities derived by SAR in absolute terms. An important aspect of this process consists of the materialization of the object used as a control point, while its selection may depend on the geological context. Typically, due to the inevitably high cost of installation, very accurate monumentation is reserved only for a limited density of points on the territory; therefore, a type of negative correlation exists, in terms of reliability in the monumentation of the control points, with respect to their density in a real distribution within a specific monitoring technique. For example, in levelling networks, a density of one benchmark every 700–1000 m of line is often desired in order to reach a compromise among costs, practical operative requirements and precision. Levelling benchmarks are usually fixed on existing structures (i.e. buildings or concrete structures). This aspect is even more evident in the case of SAR interferometric analysis, where the persistent scatterers (PS) are identified based on the coherence in the radar response. Therefore, the PS display movements are measured by a variety of different structures, characterized by foundations fixed at different depths.Starting from repeated levelling measurements, we verified the order of magnitude of movements of control points characterized by shallow foundations in cohesive soils. In practice, we observed their behaviour in relation to the depth of the foundation under simple and very common conditions, such as the presence of periods of drought or rainfall. The results indicate movements in the order of 3–7 mm in the first metre of depth that occurred in a week during the transition between the period of summer drought and the first rains. The magnitude of the total uplift observed between the end of the summer drought and the beginning of successive springtime (30/08/2012–18/04/2013) exceeded 10 cm of movement in very shallow layers of the soil surface for the same test field.

(Re-)Assessing Career Patterns in Multi-Level Systems: Insights from Wallonia in Belgium

This article proposes a new analytical framework for the study of political careers in multi-level systems. It is argued that the study of vertical movements between political arenas, which constitutes the prevalent methodological approach in the literature on political careers, should be complemented by the study of horizontal movements within political arenas. Based on a longitudinal analysis of individual political careers, the micro-approach developed in this article allows the comprehension of all territorial dynamics of political careers in multi-level systems. Based on an in-depth case study of all 419 Walloon careers in Belgium, four career patterns are identified: national careers, regional careers, multi-level careers and discrete careers. Although Belgium presents an integrated structure of opportunity, it is demonstrated that key evidences underline the prevalence of a regional and a national political class along a highly integrated political elites.

On the relative vertical movement between crust and sea level along the Chinese coastal zone: A national basic research project in China

There are about 18,000 km of coast lines in China, therefore the study of the relative vertical movement between crust and sea level along the Chinese coastal zone is one of the national basic research projects in China. This project is very important for the investigation of the effect of global change on the long‐term economic development plans of towns, cities, and rural areas located in the Chinese coastal zones. The project consists of four parts as follows: 1. Monitoring and study of the vertical movement of sea level along Chinese coast lines, taking advantage of the 30‐year records of the main tide gauge stations in China to study the general rules and trends of the vertical movement of sea level for the Bohai Sea, the Yellow Sea, the East China Sea, and the South China Sea respectively. 2. Monitoring and study of the vertical crustal movement in Chinese coastal zones with leveling, to densify and improve the local monitoring leveling networks in the coastal zone, to reposition the main tide gauge...

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.

Geodetic observations for the detection of vertical crustal movement

The significant limits within which crustal movement can be determined by geodetic survey methods depend on the quality of the observations, the stability of the markers in the network, and the structure of the network. The paper presents a study of vertical movement in the Lac St. Jean area of Québec. The data used covers the periods 1919–1938 and 1962–1966. With reference to a line of levels from Ste. Anne de la Pérade to La Malbaie along the north shore of the St. Lawrence River, the results show annual uplift as high as 10 mm at Seneterre and subsidence amounting to 4 mm at Stoneham, north of Quebec City. Confidence intervals, at the 95% level, for rates of movement are given as indicators of the quality of the results.

A preliminary study of vertical movement of Eudorina elegans and trinema lineare during a bloom caused by them

The paper describes a polluted pond from India, which exhibited a well marked thermal stratification in summer. The surface and bottom strata of water exhibited a temperature difference of 8° C. The paper also describes the diurnal movement of Eudorina elegans and Trinema lineare which formed a bloom in the pond. The movements of these organisms are interpreted on the basis of fluctuations in temperature and light conditions. The possibility of the competition for space is also discussed.