Lindu Software: A Free Seismological Data Processing Software For Traveltime Tomography Using Python Framework

Earthquake data can be used to infer some physical properties for representing the subsurface condition. The 3-Dimensional (3D) seismic velocity structure as a kind of these important properties contains the information of variation in lithology change and fluid saturation. The most common method for inverting from the travel time of seismic event into 3D seismic velocity structure is travel time tomography which is based on the relation between velocity and travel time of P- and S-wave. Based on this concept, we develop a module of Lindu software to infer this seismic velocity structure from travel time data. This module is a part of seismological data processing sequences that have been integrated into Lindu software. The Lindu software uses Python framework, a kind of high-level programming languages. The pseudo-bending raytracing method is employed to calculate the travel time between the event sources and stations and also to build the kernel matrix. The resolution test that relates density of rays and resulted tomogram uses the synthetic Checkerboard Resolution Test (CRT) by using Damped-Least Squares (DLS) method for the inversion. For validating this module, it has been tested by using both synthetic and real data.