Tomografia sísmica de alta resolução com gerador de ondas elásticas

Abstract

Several seismic surveys were carried out in the urban Palmela region (Azeitão), using 48 channel seismograph and single geophone per channel. The scope was mainly to test the efficiency and reliability of seismic source, an elastic wave generator using an accelerated hammer drop, to produce shallow velocity models with high resolution. A 300 m profile was acquired and the position based on constant topography and neighbouring the wells location previously drilled for aquifers delineation. Despite the presence of significant urban and coherent noise, the seismic source revealed effective to sum several shots and enhancing the ratio signal/noise. First arrivals processing illustrate clearly the geological structures until 60 m depth. A preliminary stack section did not support the findings in the first arrivals study. To resolve the difference, the field reflection data are being reprocessed to provide more details about the layering and lateral structures already observed in the refraction data.