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 the continental environments. We study the French Massif Central located within the West-European platform, the Gujarat area situated at the northwestern edge of the Indian shield, and northeast Egypt located in the northeastern corner of the African continent.
These regions exhibit different level of seismic activity. The French Massif Central is characterized by lowest level of seismicity, northeast Egypt exposes the 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 a wide set of geophysical and geological data, 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 potential earthquake sources is a key issue 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.
Источник: Gorshkov, A., Hassan, H.M., Mandal, P. Novikova O. Identifying Potential Earthquake Sources in Continental Environments. Surv Geophys (2022). DOI: 10.1007/s10712-021-09683-z