Of The Territories In View Of The Study
Principles of distribution the geodynamic risk
of the territories in view of the study
the accident-rate of the objects
on the sea coast and floor
which are ecologically dangerous
I.L. Uchitel1, I.I. Gladkikh2, B.B. Kapochkin3
1OAS "Odessagas"
2State Maritime Academy of Odessa, Ukraine
3Hydrometeorological Institute of Odessa, Ukraine
Problems of oil and gas production, transportation of ecologically dangerous substances through pipelines on the sea floor, work of the ecologically dangerous productions on the seacoast are closely connected with the big risk of accidents and as a consequence – ecological catastrophes. One of the most important tasks is to define the degree of risk when the ecologically dangerous objects may be damaged and to distribute the threat according to territorial principle. It is very important to know the degree of geodynamic risk in this or that territory.
At present a lot of countries have accumulated a great number of exact measurements of both global and regional character-geodetic, oceanographic, astronomic, geophysical and so on, that rather vividly show the fact, that there are no such stable points on the Earth’s surface which were not subject to constant changes in time and space. This paradigm is important not only in theoretical aspect but also has a direct practical meaning as it demands the change in construction ideas of big objects and communication nets. These objects should be adapted to the real conditions of constantly changing mobile Earth’s “solid surface”. The foundations of researches concerning the problem of modern geodynamics have been laid up by the well-known specialists U.Bulandge; U. Mescheryakov.
The study of modern vertical motions involves the solution of several complicated scientific and methodic problems. These problems should be taken into consideration using the information of charts for evaluating and prognosing purposes. One of such problems is to calculate the absolute value
of motions speed. The average ocean level for many years `is taken as an absolute zero, then depth gauge data in the system of geodetic net are transmitted deep into the continent. In the process of smoothing the data of instrumental measurements along the particular lines of leveling, inevitable distortion of the initial data occurs in geodetic chains and the systems of geodetic chains. Besides due to the difference in time between leveling in different regions, the charts in these regions are of non-equal quality. That is why “absolute values” of the speed are in a way of approximate character and they should be used rather carefully. The most important information in the charts of vertical motions is the laws of space differences of the speed values and their relative changes that can be safely used for general interpretation.
In the condition of intensive manifestations of exogenous processes, the study of peculiarities in the spreading of the forced gravitational waves along the structurally divided Earth’s surface has along with theoretical, also a great practical importance, as it forms the opinions in the sphere of geodynamic and seismic division of the territories as a problem of territory division on the factor of geodynamic risk is extremely urgent.
The purpose of the present research is to create theoretical base for space division of the territories on the factor of geodeformating risc from quick geodynamic processes with the practical outcome in the sphere of designing and maintenance of ecologically dangerous productions on the basis when the relations are stated between geological structure of the Earth’s crust and the character of deformations which are caused by the gravitational wave deformations of different space and time scale. Practical result is also evident for the use of peculiarities in tectonic and morphostructural structures of the region when designing and reconstructing the existing objects, pipelines inclusive. Monitoring data of the geodeformating processes of the Earth may be also used to diagnose emergency situations as well as for short-term prognosis of the gaspipeline sections, which are subject to maximum influence of the geodynamic processes.
To achieve the mentioned above goals, the decision of the following tasks should be realized.
1.To work out the criterion to evaluate the quality of initial information. With the help of this criterion it will be possible to tell the beginning and the end of activation periods for quick geodynamic motions.
2.To find indicators which characterize orientation change of geodeformating field and change of tension intensity in the Earth’s crust.
3.To state interrelations between geological structure of the Earth’s crust and the character of deformations caused by gravitational wave deformations of different time and space scale.
To create theoretical and methodological basis to make the methods of dividing territories more perfect with regards for peculiarities in spreading of quick geodeformating processes as well as with regards for tectonic and morphostructural structures of the region. This basis can be also used when planning precise geodetic survey, when designing new and reconstructing the existing productions that are ecologically dangerous, pipelines inclusive, and at last to use monitoring data of geodeformating processes to raise diagnose quality of emergency situation and short-term prognosis of territories that are subject to maximum influence of geodeformating processes.
For the first time the phenomenon of quick changes in the geodeformating fields of the Earth having the global character was discovered in the beginning of 70-ies and registered as a scientific discovery under the name of “Vartanyan-Kulikov effect”. Earlier it was considered, that geodeformating processes of tectonic nature are characterized only by long-term changes with the periods of decades-centuries and occur only in seismically active regions, where the processes of orogenesis take place as well as active dynamics of plates connected with the processes of spreading and subduction. At present it is generally recognized that the phenomenon of quick change in orientation of the Earth’s geodeformating field (with the periods of days-weeks) has global character.
Practically all mentioned above is very important for purposes of diagnosis and prognosis of the accidents on pipelines as well. As it is pointed out in the works by V.M. Sheremet’ev, – industrial accidents are considered as a consequence of geodeformating processes variations. The ten-year-old experience of geodeformating field monitoring in Krasnodar region allowed to classify the types of hydrogeodeformating changes among which attention is attracted to the distinguished “vibrational condition along the lines of fractures”, which is probably the effect of gravitational deforming waves. Study of peculiarities in the geodynamic processes has any prospect only in the regions with clearly distinguished geodynamic condition and also (which is not unimportant) in the periods when geodynamic motions are activised. In this respect Odessa was found a proper place to conduct the researches and the period of research works 1992-2000 coincided with the active phase of geodynamic processes.
Principal importance has a correct strategy of monitoring. In the present research along with data of seismic, geothermal direct measurements of deformations there were also used the data of registered violations in gas-tightness of the thick net of gaspipelines that evenly covers the territory of Odessa. This territory is a complicated morphostructural object – a point where the Main Black Sea and Odessa-Sivash neotectonic zones cross. Information about violations of gas tightness on the gaspipelines is continuously registered by emergency service of “Odessagas” company. Registration includes fixation of fractures in space and dynamics of the processes in time. As it is shown by the researches, there exists an immense influence of geodynamic processes upon violations of gaspipelines tightness.
As a result of conducted researches the results were obtained that are of fundamental character and of big practical value.
Principle results of the researches are given below:
1.Temporal change in the accident-rate of the gas nets belonging to “Odessagas” company within the period of twenty four hours is very often shown by the sequence of accidents interchanged by not- accidental periods which are greatly different from the average meaning.
2.In the period of year there are stages of monotonous growth in temporal intervals between accidents followed by the rapid growth of accidents.
3.In the period of abnormal quality of accidents, their spatial distribution can be classified into several types, alike the analogous existing classification of microseismic manifestations. This classification reflects deformating processes of the interblock process.
4.There was discovered considerable spatial heterogenity of gaspipeline accident-rate in the Odessa territory.
5.Temporal and spatial sequence of accidents in abnormal days is usually connected with the maximum deformations of tidal (influx) origin and reflects the processes of interaction between complex block structure of the Earth’s crust and appearing deformations of wave origin .The deformations also trace the borders of blocks and their joint places.
6.The growth periods of tectonic tensions are distinguished by seismic manifestations as well as by abnormal manifestations in the tensely deformed state of the geological environment. These tensions are discovered by indirect signs and characterized by rapid decrease in the level of urban gaspipelines accident-rate.
7.Condition is created for dividing the territory according to the fact of geodynamic risk in view of accident-rate on the urban gaspipelines. Tese conditions are based on the mapping of morphostructural elements that are of high strain gauge sensitivity and abnormal wave-conducting characteristics.
8.Prospective trends for researches were worked out that are aimed to provide diagnosis for the territories that are subject to geodynamic risk with regard for temporal changes in the tensely deformed state of the Earth’s crust.
9.There were marked out prospective trends of researches aimed to provide the prognosis of long-term changes in the level of strain gauge sensitivity and tectonically weak mapped zones of different orientation.
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