Method and results of electrometric observations in seismically active region

Any increases in the accuracy of measurement of rock impedance will afford new possibilities for diagnosis of its state and use of the electrometric method in research on earthquake prediction. The article describes the fundamental principles and methods for contending with noise in electrical sounding which make possible a considerable increase in the inefficiency of accumulations and gives some results of observations of variations of impedance in the Garm geophysical test range in the seismically active part of the Tajik SSR. An optimum accumulation algorithm was developed on the basis of the statistical properties of a large number of records of noise observed during electrical sounding. The great volume of research data ensured full automation of the experiment by direct input of data from a precise digital measuring instrument into a minicomputer where they were processed using different algorithms at a real time scale. Measurements are made once a day in half-hour intervals. The pulse repetition rate was 24 sec and the duration of one accumulation cycle was 132 sec.