Rewrite FDtomo-Fortran (a famous geoscientific program) in C language with OpenMP pragma. Contributed >11,000 lines. I speed up earthquake locating module with OpenMP pragma. Locating 150k earthquakes only take <500mins, the original version needs >6000mins. (environment: intel xeon 32 core cpu) https://github.com/ncu-psl/FDtomoC