Earthquakes are natural hazards causing significant damage both in cost to human life as well as property. Most recently, adjacent to Europe, on June 27, 1998, an earthquake in the Adana basin of eastern turkey killed several tens and destroyed much man-made constructions. A fundamental step in seismic hazard assessment is refinement of our knowledge of smaller earthquakes those that are the source of major hazard in Europe and adjacent regions. Due to complexities introduced by propagation of waves through upper mantle, waveforms from small events recorded at intermediate distances are difficult to interpret. A powerful tool to overcome this problem is the Gaussian beam summation.