Seismic instruments: article

Аnnotation: The paper describes the automatic system for monitoring the seismicity of the European Arctic, built on the basis of a network of seismic stations of a different countries located in the region. The core of the system is the software package for automatic detection and location of seismic events NSDL developed by the authors. NSDL is designed to monitor automatically the seismic activity of a region using a network of seismic stations, seismic arrays or individual three-component seismic stations. The described system has two levels. The first level includes single station processing programs that implement algorithms for detecting and pre-locating seismic events from the data of individual three-component seismic stations and seismic arrays. The second level is the program of association of the results of processing for individual stations performing joint location on the network of stations on the basis of events and phases of seismic waves detected at the first level of the processing. NSDL allows to use of a set of one-dimensional layered velocity models for the location of distant events, the propagation paths of waves from which cross regions of the medium with different velocity properties. Decisions on the truth or falsity of the detected candidate events are made by Bayesian classifiers, based on the evaluation of a number of amplitude, spectral, and polarization parameters, both for single-station and joint seismic event processing. The application of the system for seismic monitoring in the Arctic region showed high reliability of automatic results, significantly accelerated the process of compiling final catalogs, verified by analysts, and significantly increased the representativeness of the resulting bulletin due to weak events. The detailing achieved through the application of the described system allows us to take a fresh look at the development and structure of the seismic process in the European Arctic, in particular, to record seismic events associated not only with tectonic processes, but also with cryosphere destruction processes.