f Attenuation versus fracture using different methods

According to the present study about seismic field data of the North east part of IRAN, relationship between velocity, fractures and attenuation of rocks was investigated. The seismic refraction data was produced by blow and explosion sources. In this paper, an algorithm was developed that performs many stages. The stage's sequences are consist of separation of refraction and reflection signals, correction due to geometrical spreading, resampling and transformation of data to frequency domain, filtering (low pass or band pass filtering), spectrum of data, and then pass from pan filter. Consequently, determination of absorption spectrum of rocks and quality factor (Q) was attained.Processing of these data showed that due to increase of fractures, the values of VP and VS decrease considerably. Then, amplitude of observed data and determination of quantities such as absorption coefficient α(f) and quality factor (Q) for P- and S-waves in rocks were performed. For a partially dry rock the results obtained in fractured area suggest that, while fracture increases in rocks the absorption increase and factor decrease.