Seismicity of blasting operations in Karelia

Abstract

Modern changes in the Earth’s crust take place under the joint influence of the natural tectonic forces and the progressive anthropogenic activity. The induced type of seismicity prevails in the territory of Karelia, which mainly includes active blasting operations. The study of blasting-induced seismicity is relevant considering numerous industrial facilities present in the territory of Karelia (construction and operation of large structures, roads, pipelines, hydroelectric power plants, etc.). Based on the seismic data obtained in 2018–2019, the induced seismicity map is built and the time characteristics of the blasting operations performed are analyzed. The purpose of the study is to assess the level of seismicity induced by blasting operations in Karelia. In the early 2000s, the seismological network was created in the territory of the Republic by the Institute of Geology, Karelia Science Center RAS. The network is equipped with modern digital equipment that allows seismic monitoring of the whole territory of Karelia. The layout of epicenters of the induced events recorded in Karelia is presented. A brief description of the mining activity is given together with its reflections in the seismic record for each region. The time profiles of the blasting operations were built. The studied seismicity comes out at 4:00-18:00 (UTC). Most blasting operations in Karelia are carried out at 9:00-11:00 (UTC). A fewer seismic events are recorded in summer than in winter, and the number of seismic events exceeds 300 per year. The observations show that the blasting-induced seismicity is recorded in many regions of Karelia. The western part of the region is characterized by more frequent and stronger events than the eastern part.The study was carried out within the framework of Topic No. 213: 3D Model of the Lithosphere of Karelia Based on the Geological and Geophysical Data, No. АААА-А18-118020290086-1.