No abstract

No abstract

The first results of unique experiments on the synchronous registration of seismic-strain oscillations of the Earth’s surface by three laser interferometers-deformographs (strainmeters) spaced 6740 km apart are presented. Two 100-meter laser interferometers at the Fryazino site (Moscow Region) and the 18-meter laser strainmeter at the observation point of Karymshina (Kamchatka Peninsula) were applied. The frequency-stabilized and thermally controlled lasers and the interferogram registration systems of compensation and modulation types providing an absolute instrumental resolution of 0.1-0.01 nm were used. The results of data analysis in sessions of synchronous operation of these instruments during 2016-2020 were obtained and discussed.

No abstract

No abstract

Abstract. The most destructive disasters such as the strongest earthquakes and the most powerful tropical cyclones can be treated as tightly coupled geophysical phenomena in their origin. Results of comparison of geophysical field variations and seismic activity of the Earth have evidently shown the correlation between lithosphere–atmosphere interactive disturbances, tropical cyclonic activity in the World Ocean, and seismic processes in the solid Earth. The ground-based laser interferometer techniques being supplemented by satellite observational systems can be considered as promising methods for common earthquake and hurricane monitoring and prediction.

No abstract

The determination problem of wide band wave field parameters in continuous mechanical media is considered. The problem is solved by means of the accurate measurements of displacements and strain of the certain number of medium elements together with subsequent numeric development and data processing.The oscillations which are excited by the source of any physical nature in the continuous mechanical medium can be presented as some superposition of relative spatial displacements of medium particles. These displacements cause the variations of pressure or tension in the medium depending on their mechanical properties.The simple problem of the acoustic wave tests in the liquid or gas medium is usually solved by measurements of the temporal pressure variations dp ( t ) at some point x within this medium. In the threedimensional case, the space-time distribution of the scalar pressure field is the function of four variables:where t is time.pressed as follows:The equation of such a medium motion is ex-where: v is the velocity vector of the particle spatial displacements