Search Results

You are looking at 1 - 2 of 2 items for :

  • Author or Editor: M. Saleh x
  • Earth and Environmental Sciences x
  • Refine by Access: All Content x
Clear All Modify Search

Magnetotelluric method (MT) offers opportunity to detect crustal fluids along faults due to their high conductivity anomaly. Supposing that fluids deposited minerals in the conductive fractures (faults, dykes) decreasing the resistivity, the high seismicity in the area can be explained by the presence of these fluids. MT measurements were carried out in the period range 0.001–420 s crossing the Kalabsha fault (Aswan, Egypt) and Remiremont fault (Southern Vosges, France). In these work we detect geoelectrical resistivity anomalies of the Earth’s crust and link them to local seismic activity. Seismic events having magnitude (M<5) are found along fault zones in Kalabsha and Remiremont. The goals of our measurements are various. We would like to determine the precise location of the active faults, to study the connection of the Remiremont and Kalabsha seismicity to the MT resistivity structures, and to support the idea of the influence of the fluid-bearing conducting faults in the Remiremont and Kalabsha areas to the earthquake. These applications afford the unusual opportunity to study the percolation of water into the faults system and its effect on the seismicity, to reveal geological structures and the stress field covered by thin Quaternary formations. Data are analysed by 2D simultaneous inversion of both polarizations. The resulting models are compared with the local seismicity map. Our MT model reveals the conductive signature of the fault, as well as geological and tectonic stresses prevailing in active regions.

Restricted access

Abu-Dabbab area is characterized by high seismicity and complex tectonic setting, for these facts, a local geodetic network consisting of eleven geodetic benchmarks has been established. The crustal deformation data in this area are collected using the GPS techniques. Five campaigns of GPS measurements have been collected, processed and adjusted to get the more accurate positions of the GPS stations. The horizontal velocity vectors, the dilatational, the maximum shear strains and the principal strain rates were estimated. The magnitude of the movements is distributed inhomogeneous over the area and it varies in average between 3 and 6 mm/yr. The results of the deformation analyses indicate a significant contraction and extension across the southern central part of the study area which is characterized by high seismic activity represented by the clustering shape of the microearthquakes that trending NE-SW direction. The north and north-eastern parts are characterized by small strain rates. This study is an attempt to provide valuable information about the present state of the crustal deformation and its relationship to seismic activity and tectonic setting at Abu-Dabbab area.

Restricted access