ИСТИНА

The work presents results of statistical analysis of the spatial-temporal distribution of strong aftershocks. Data from the world catalog of earthquakes NEIC USGS from 1973 to 2014 (https://www.usgs.gov) and from the regional earthquakes catalog of Northern California from 1968 to 2007 (http://www.ncedc.org) were used. Short time intervals were considered - no more than 10 hours before and after main shock and distance from the epicenter of the main shock - up to 5 degrees. The distribution of the aftershocks number in the time-distance coordinates from the main shock was investigated. The method of superposed epochs was used. The main shocks performed the function of reference mark for the synchronization of sequences of repeated shocks. To each main shock was attributed the conventional time equal to zero, and its epicenter coincided with the origin of coordinates. The main shocks with magnitude Mms ≥ 7.5 and aftershocks with 6 ≤ Mas < Mms for the world catalog NEIC USGS and the main shocks Mms ≥ 5 and aftershocks with 4 ≤ Mas < Mms for Northern California catalog were considered. It is shown that the spatial-temporal distribution of strong aftershocks forms a similarity of a wave structure. The work was supported by the Government task # 0144-2014-00116 and RFBR project # 18-05-00096.