Assessment of the Efficiency of Armenian Seismological Networks

Abstract

For successful prediction of strong earthquakes, seismic risk zoning, and earthquake-resistant construction, it is necessary above all to have a sufficiently clear understanding of the hypocentral distribution of earthquakes in the area in question. In order to determine the position of earthquake foci with high accuracy, it is necessary to have an observation system capable of this. The modern seismological network in the Republic of Armenia (RA) essentially consists of two independent networks that barely interact with each other. Moreover, each network uses its own data processing methods (for determining hypocenters and travel-time curves). One network belongs to the National Seismic Protection Service under the Ministry of Emergencies of the Republic of Armenia (NSPS RA) and consists of 16 stations; the other is subordinate to the Institute of Geology of RA National Academy of Sciences (IG NAS RA) and hosts 14 seismic stations. Both networks are set up unevenly in the territory of Armenia, and each has its own disadvantages. The IG NAS RA network is sparser (with only 14 stations), and its stations are located only in northwestern Armenia. Therefore, it cannot accurately localize the hypocenters of earthquakes throughout the republic. The NSPS RA network consists of 16 stations. They are also located unevenly across Armenia, but at the same time, they encompass the southeastern part of the country. Calculations have been performed and maps compiled of the distribution of minimum energy classes and maximum errors in determining hypocentral coordinates of earthquakes recorded both separately by the IGN NAS RA and NSPS RA networks and by the integrated seismic network. It is shown that when the networks are combined, localization of earthquake hypocenters improves somewhat, but the territory between northwestern and southeastern Armenia remains virtually uncovered. This is because, at present, the stations of both existing networks, on the one hand, duplicate each other in some cases, while on the other, they are located unevenly across the territory. To obtain more accurate and reliable information, it is better to have a single network with be uniformly placed throughout the republic.