30. Calculation and plotting of travel times

In SEISAN, travel times are generated from a flat crustal model or using the IASP91 global travel time model. It can often be useful to generate travel times for given distances and two programs are supplied to do these calculations. TTIM will calculate travel times for global phases at one given distance and depth and TTLAYER, will calculate a travel time table (layered flat model) for a given depth and a distance range. A special version of TTIM called IASP is used in connection with EEV and MULPLT.