In this paper, we discuss the correlation between isoseismal contour maps and gravity residual anomaly maps and how it might contribute to the characterization of vulnerable areas to earthquake damage, especially in urban areas, where the geophysical data collection is difficult. More specifically, we compare a couple of isoseismal maps that have been produced and published after the catastrophic earthquake of 7th September 1999 (5.9R) in Athens, the metropolis of Greece, with the residual map produced from the processing and data reduction of a gravity survey that has been carried out in the Athens basin recently. The geologic and tectonic regime of the Athens basin is quite complicated and it is still being updated with new elements. Basically it is comprised of four different geotectonic units, one of them considered as the autochthon. During the gravity investigation, 807 gravity stations were collected, based on a grid plan with spacing almost 1km, covering the entire basin and supported by a newly established gravity base network comprised by thirteen bases. Differential DGPS technique was used for the accurate measurement of all the gravity stations and bases coordinates. After the appropriate data reduction and the construction of the Complete Bouguer Anomaly map, we applied FFT filtering in order to remove the regional component and produce the Residual Anomaly Map. The comparison of the Residual Anomaly Map with the isoseismal contours revealed that the areas with the most damage because of the earthquake were located in the areas with the minimum values of the Residual Anomaly Map.

In this paper we discuss the preliminary results of the Transient Electromagnetic Method (TEM) that was applied in the area of Karla Lake, located in the East Thessaly basin. A grid of 71 TEM soundings was planned and executed in order to investigate the subsurface lithological and hydrogeological conditions of the area. The geological regime of the area is comprised of the alpine basement (marbles, gneisses and schists), ophiolites, transgression formations and finally a package of post-alpine deposits with respectful thickness. Resistivity maps for certain depths of investigation along with a pseudo-3D representation were produced, based on the processed TEM data. The vertical distribution of the resistivity values revealed important information about the lithological succession of the area and the hydrogeological status of the post-alpine sediments covering the basin. Moreover, the limits of the former Karla Lake were delineated and the alpine bedrock was also adumbrated under the thick Tertiary and Quaternary deposits. Finally, taking into account older piezometric maps of 2009 and our geophysical results, we managed to indicate the decline of the groundwater level since then, in the central part of the study area and the broader area of Kileler settlement.