An Attempt To Invert Tomography Delay Time Problem With Hybrid Lsqr

Abstract

Indonesia is situated in Southeast Asia’s active tectonic zone, influenced by the movement of four plates: the Eurasian Plate in the south, the Eurasian Plate in the north, the Philippine Plate, and the Pacific Plate in the northeast. The Tomography approach was used in this work to obtain a stable solution, which was achieved through regularization. Least Square and Hybrid Lsqr are the inversion methods employed. This research aimed to use the IR Tools Package Irhybrid LSQR to investigate inversion tomography with regulatory approaches in 3D. In this study, Matlab is used to perform inversion tomography. Two types of data, real and synthetic, are employed at this stage. The study’s genuine data came from earthquake catalogues from BMKG, MARAMEX, DOMERAPI, and BPPTKG, with depths ranging from 0-658 km and recorded between 20 December 2013 - 6 September 2020, with an area boundary of 110.1 – 110.8. LS -7.8–7.2 BT. The red colour represents the magma reservoir area according to the inversion data. Hybrid LSQR is an iterative approach that is considered stable enough to be used in tomography. When applied to tomographic coding and compared to the most widely used inversion method, Least Square, the results obtained in the least Square have a higher value than Hybrid LSQR.