EARTHQUAKE FORERUNNER METER Russian patent published in 2003 - IPC

FIELD: seismology, national systems to monitor and process data of geophysical measurements to forecast earthquakes. SUBSTANCE: measurement channels are spaced apart by distance commensurable with dimensions of earthquake zone. Differential bridge circuit is so balanced that its output resistance in absence of forerunner signal is close to zero and does not exceed voltage of specified threshold of threshold element. With emergence of heavy electrostatic field its value in points of location of spaced-apart meters will markedly differ. Light signal from optical radiation generator will be sent over fiber-optical lines to sensitive elements of electrooptical sensors. Modulated luminous flux is transmitted over fiber-optical line to photodetector which converts optical signal to electric signal. Emergence of sign-forerunner in the form of heavy electrostatic field will lead to unbalance of differential bridge circuit. After some time output voltage of circuit will exceed threshold voltage of element preset by programmable retrieval circuit. Operation of threshold element is determined by service program. EFFECT: increased accuracy, authenticity and timeliness of forecasting. 3 dwg