Why we cannot predict strong earthquakes in the Earth’s crust

Abstract

In the past decade, earthquake disasters caused multiple fatalities and significant economic losses and challenged the modern civilization. The wellknown achievements and growing power of civilization are backstrapped when facing the Nature. The question arises, what hinders solving a problem of earthquake prediction, while longterm and continuous seismic monitoring systems are in place in many regions of the world. For instance, there was no forecast of the Japan Great Earthquake of March 11, 2011, despite the fact that monitoring conditions for its prediction were unique. Its focal zone was 100–200 km away from the monitoring network installed in the area of permanent seismic hazard, which is subject to nonstop and longterm seismic monitoring. Lesson should be learned from our common fiasco in forecasting, taking into account research results obtained during the past 50–60 years. It is now evident that we failed to identify precursors of the earthquakes. Prior to the earthquake occurrence, the observed local anomalies of various fields reflected other processes that were mistakenly viewed as processes of preparation for largescale faulting. For many years, geotectonic situations were analyzed on the basis of the physics of destruction of laboratory specimens, which was applied to the lithospheric conditions. Many researchers realize that such an approach is inaccurate. Nonetheless, persistent attempts are being undertaken with application of modern computation to detect anomalies of various fields, which may be interpreted as earthquake precursors. In our opinion, such illusory intentions were smashed by the Great Japan Earthquake (Figure 6). It is also obvious that sufficient attention has not been given yet to fundamental studies of seismic processes. This review presents the authors’ opinion concerning the origin of the seismic process and strong earthquakes, being part of the process. The authors realize that a wide discussion is needed to address the issues raised in this publication, including problems and possibilities of prediction of earthquakes in the crust. Incontrovertible achievements of the Earth sciences are reviewed, considering specific features of seismic events and variations of various parameters of the lithosphere, the block structure of the lithosphere and processes in the lithosphere. Much attention is given to analyses of driving forces of the seismotectonic process. The studies of variations of parameters of the medium, including rapid (hourly or daily) changes, show that processes, that predetermine the state of stresses or the energy capacity of the medium (Figures 2 and 3) in the lithosphere, are overlooked. Analyses are based on processes of interactions between ascending flows of hydrogen and helium and the solid lithosphere. A consequence of such processes is gas porosity that controls many parameters of the medium and the oscillation regime of the threedimensional state of stresses of the block structures (Figures 6, 7, and 12), which impacts the dynamics of block movements. The endogenous activity of the lithosphere and its instability are controlled by degassing of light gases. The paper reviews processes of preparation for strong earthquakes in the crust with regard to the block structure of platform areas and subduction zones (Figures 13 and 14). It is demonstrated that the conventional methods yield ambiguous assessments of seismic hazard both in terms of time and locations of epicenter zones, and focal areas of subduction zones are out of control in principle. Processes that actually take place in the lithosphere are causes of such an ambiguity, i.e. the lack of any deterministic relations in development of critical seismotectonic situations. Methods for identification of the geological medium characterized by continuously variable parameters are considered. Directions of fundamental studies of the seismic process and principles of seismic activity monitoring are considered.