Identifying Potential Earthquake Sources in Continental Environments

Abstract

In this paper, we outline the overview of the problem of intraplate seismicity and summarize our studies aimed at identifying potential earthquake sources in three regions located in continental environments. We study the French Massif Central situated within the West-European platform, the Gujarat area located at the northwestern edge of the Indian shield, and northeast Egypt located in the northeastern part of the African continent. These regions exhibit different levels of seismic activity. The French Massif Central reveals the lowest rate of seismicity, northeast Egypt exposes a low-to-moderate seismicity, and Gujarat reveals moderate seismicity with rare occurrence of strong events. We use a phenomenological approach for identifying possible locations of earthquakes, which is based on the pattern recognition applied to morphostructural data. The approach hypothesizes the nucleation of strong earthquakes at morphostructural nodes forming at the intersections of morphostructural lineaments, which are delineated by morphostructural zoning. Nodes are characterized by the pertinent geophysical and geological parameters, on the basis of which pattern recognition algorithm pinpoints capable nodes, i.e., the nodes where events of a certain sizes may occur. Seismic hazard assessment of continental regions is impeded because their seismic history is normally very pure. In such a situation, information on capable nodes is a necessary input for seismic hazard assessment. The example of northeast Egypt shows the exploiting capable nodes to assess seismic hazard by the Neo-Deterministic Seismic Hazard Assessment Methodology.

Guest Editorial: Special Issue on “Lithosphere Dynamics and Earthquake Hazard Forecasting”

“…A few key factors influencing the earthquake sequences, clustering, and magnitudes are identified including lithospheric plate driving forces, the geometry of fault zones, and their physical properties. Gorshkov et al (2022) provide an overview of the problem of intraplate seismicity and summarise studies on the identification of potential earthquake sources in continental regions exhibiting different levels of seismic activity. A pattern recognition method is used for morphostructural data analysis.…”