Motivation

One of the most dangerous types of natural disasters with which humanity have not yet learned how to cope is strong earthquakes. Every year due to earthquakes dozens or even hundreds of people die, thousands become homeless. Earthquakes also produce huge economic losses. Despite considerable progress in the field of earthquake prediction in recent decades, destructive earthquakes continue to occur; very often they occur in areas where seismic risk is underestimated. Furthermore, substantial part of damages is often caused by strong aftershocks because constructions damaged during the main shock can be completely destroyed when exposed to even relatively weak repeated concussions.

After every major earthquake when it occurs in a populated area or in close proximity to some energy or other important objects in any country, some questions arise: Should we expect a strong aftershock? How long? In what area? How strong? Obviously, in case of a positive answer to the first question it is inevitable to use additional material costs because waiting for long time can cause much higher expenditures. At the same time, ungrounded decisions made about the absence of danger from destructive shock can bring losses if it happens, such losses can be compared to the loss from the main shock and sometimes it can be even larger.

Currently, authorities with help of estimations done by scientists and experts make such decisions. This approach has a number of obvious shortcomings. In particular, shortcomings were widely noticeable after a famous story when a few seismologists were brought to court in Italy after the earthquake of 2009 in L’Aquila.

Development of an automated system of algorithmic estimation of aftershock probability with a given size can give an opportunity to clearly and quickly make a decision by competent authorities about evacuation of people, recommendations for a particular period of time to leave specific buildings and facilities, when to stop and resume transportation system, energy objects, and other objects of dangerous productions, etc., which will in turn reduce the effect of earthquake.

Novelty of the problem for the Earth science is defined by fundamental as well as practical components. Thus, fundamental significance of the problem is in planned solutions for several problems of evaluating the seismic danger based on the data of complex geophysical monitoring in operated mode which allow to answer significant questions arising after strong earthquakes: Is it feasible to expect strong repeated shocks? During what time? How strong would they be? Furthermore, practical significance of solving this problem is in diminished consequences of catastrophes triggered by repeated and strong shocks with the help of information automated system based on probated tools and operated data of complex geophysical monitoring. Detailed monitoring will allow for renewing the estimations of seismic danger as decay of an aftershock activity happens.