1. Formerly University of Houston, Department of Earth and Atmospheric Sciences, Houston, Texas 77204, USA; presently Ain Shams University, Department of Geophysics, Cairo 11566, Egypt.(corresponding author).
2. University of Houston, Department of Earth and Atmospheric Sciences, Houston, Texas 77204, USA..
3. Auburn Energy, Weimar, Texas 77024, USA.
4. Differential Seismic LLC, Houston, Texas 77079, USA..