Vol 53, No 1 (2017)

This paper reports the long-term teamwork results obtained by an expert group from the Radiophysical Research Institute (NIRFI) and VEGA Geophysics Ltd. (VEGA, St. Petersburg) in the course of designing modern induction-coil magnetic field sensors. A comparative analysis of the world’s most famous sensor models is carried out, and basic design and testing methods and features are considered. The range of low-noise induction-coil magnetometers (IMS-007, IMS-008, and IMS-009) designed by the authors for scientific and geophysical ground-based explorations is described. Research results are obtained from using the sensors for geothermal water exploration by broadband magnetotelluric sounding, investigation of the deep structure of the lithosphere by controlled source electromagnetic sounding, and monitoring of the Earth’s natural electromagnetic field.

The paper presents results of instrumental observations of seismic processes and variations in the Earth’s magnetic field at the stages of nucleation and development of earthquakes in the Chinese provinces of Qinghai, Sichuan and Yunnan. Data on manifestations of all these strong seismic events are indicated. Monitoring of the changes in the magnetic field is based on data obtained at the Northern Caucasus Geophysical Observatory, IPE RAS and integrated observation points of the Institute of Terrestrial Magnetism, the Ionosphere and Radio Wave Propagation, RAS (IZMIRAN). The experimental results have allowed us to represent the structure of induced anomalous geomagnetic disturbances, which can be associated with the development of related geodynamic processes in the geological medium of the seismic source zone.

The KamIn information system (IS) created at the Kamchatka Branch of GS RAS to collect, store, and preprocess data on the wave perturbations in the atmosphere is described. The KamIn IS observation system and infrastructure are described in detail; they make it possible to select infrasonic signals that occur during volcanic eruptions on Kamchatka and in the northern Kurile Islands both in the operational and regular mode. The results of the IS performance in 2010–2016 are summarized.

Different variants for interpreting the data of vertical and horizontal channels of GPS measurements are examined during experimental works. The movements of an observation point are imitated experimentally in the vertical and horizontal directions at a geophysical observatory. The experiments are carried out on a pedestal with original benchmarks in both directions. The movements are imitated in the high-frequency range with different time values of movement from one point to another, which did not exceed 1 h. The errors in imaging movements of measurement points according to the results of interpreting the readings of GPS receivers are shown in relation to the benchmark movements of measurement points in the vertical and horizontal directions. These data are processed in the differential mode using the precise point positioning (PPP) method. The experimental results confirm that there is no potential of imaging vertical movements of the Earth’s surface caused by tidal observations according to GPS receiver data.