زلزله هاي ثبت شده در منطقه P مطالعه پوسته در منطقه ايذه (اطراف سد كارون ) با روش وارون سازي زمانهاي سير امواج

Study of crust in Izeh area (aruond Karoun dam) by inverting P wave travel times data recorded in the area

Method of seismic travel time inversion for simultaneous determination of 2-D velocity is used to invert p-wave data recorded by seismograms in Izeh area. The inversion scheme used is iterative and is based on a model parameterization and a method of ray tracing. To study local seismicity around Karoun darn in Izeh area, a temporary earthquake network of seismograph stations were established that during three years had recorded about 800 earthquakes occurred around the dam. The first arrival times are used as data for inversion to determine the structure of the crust in this area. An initial five- layer model with depth and velocity as parameters have been defined using the primary data interpretation and present information in the area. The Initial model is optimized by inverting p arrival times, using a program, in a manner that time response best fit with the data. The optimized depth and velocity parameters due to inversion are employed to show contour map of the interface depth of the layers and velocity variations at different depth in order to study the crust in the area. Observed discontinuities on the maps are related to the faults in the area which are proved by area geology map.