To better understand the cause of the observed behaviors of large and small earthquakes, we have determined high-resolution earthquake locations within a period of one year covering the 2008 M_w 6.0 (M6) earthquake, as well as Vp, Vs, and Vp/Vs models along the westernmost segment of the Gofar transform fault (GTF), using a well recorded ocean bottom seismograph dataset and a new Vp/Vs model consistency-constrained double-difference tomography method. Our results further suggest that strong structural variations control the fault mechanics and earthquake behavior along the GTF.