Preliminary Results: Tomographic Imaging of P-Wave Velocity Structure Beneath Kalimantan, Makassar Strait, and Sulawesi using Fast Marching Tomography Method
Keywords:
P-Wave, Seismic Tomography, Tectonic, Sulawesi, Makassar StraitAbstract
Sulawesi has significantly higher rate of seismicity than Kalimantan. Furthermore, the Makassar Strait exists, and it has a relationship with the tectonic setting of Kalimantan and Sulawesi. This study employs seismic tomography to imaging sub-surface structures beneath the Kalimantan, Makassar Strait, and Sulawesi region. The data used are earthquake arrival-times data from the Meteorology, Climatology, and Geophysics Agency (BMKG), Indonesia, from January 2017 to January 2021, containing 7.481 earthquakes and 78.610 P-wave phases. FMTOMO employs the fast-marching ray tracing method, a grid-based numerical method that employs a finite–difference algorithm. The results of the checkerboard resolution test will be displayed in this paper using a variety of grids. Then we will look at how the checkerboard resolution of each depth slice, as well as the vertical north-south, changes. The checkerboard resolution test looks for areas with high resolution that can be interpreted further using the inversion tomography method. The preliminary results show that grids with smaller spaces relatively have better recovery checkerboard, with the checkerboard model able to recover the resolution from areas with high seismicity and traversed by many ray paths. As an example, consider North Sulawesi, Central and South Sulawesi, and Southeast Sulawesi.
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