Imaging and Tomographic Interpretations of Seismic Refraction Data for Near Surface Basement Assessment in Somaliland

We present a comparison between the results of the processing of seismic profiles acquired in Somaliland, near the town of Boroma, in the frame of an UNESCO project for groundwater research. The main objective of the work was to support the siting of drilling water wells. The aim of geophysical survey was the identification of the geophysical parameters of the basement and overlying limestone unit. The data processing was performed with a classical approach based on the tomographic inversion of P first arrivals. Whereas the picking of first arrival times is sometimes difficult, we present the application of the multi refractor imaging technique (MRI) based on the stack of refraction convolution sections of the refracted signals. The results show that MRI is a suitable technique to processing and interpret the refracted data and it allows to obtain an accurate image of refracting interfaces. Further it complements and integrates the interpretation of the results obtained with tomographic approach also in presence of complex structures.