Deformation analysis due to the 2007 Mw8.5 Bengkulu earthquake using Sumatran Gps Array data


ABSTRACT Deformation analysis has been carried out by calculating the horizontal deformation vector that occurred as a result of the Bengkulu earthquake on September 12, 2007. The deformation vector can be seen from the shift of nine SuGAr stations (Sumatran GPS Array) which are scattered along the west coast of Sumatra Island, namely BSAT (Bulasat), LAIS stations. (Lais), LNNG (Lunang), MKMK (Muko Muko), NGNG (Nyang Nyang), PPNJ (Long Island), PRKB (Parak Batu), PSKI (Sikuai Island), and SLBU (Silabu). Deformation analysis is carried out by looking at the shifts that occur before the earthquake / pre-earthquake, during the earthquake / koseismic, and after the earthquake / post-caseismic. Observation data is 100 DOY (Day of Years) starting from 31 July 2007 to 06 November 2007 / DOY 211-310. This study also uses a tie point, which is 16 IGS stations. Data processing using GAMIT / GLOBK 10.70 software and mapping using GMT 5.4.5. After processing the data, the results showed that in the praseismic phase (DOY 211-254) the SuGAr station experienced a small deformation, namely 0.22 cm-0.84 cm to the northeast and in accordance with the direction of the Australian Indies plate support, and in the coseismic phase. (DOY 254-256) SuGAr station underwent a deformation of 16.38 cm-180.89 cm in the opposite direction, namely northwest. In the pascaseismic phase (DOY 256-310) the movement of the SuGAr station follows the direction of the deformation in the koseismic phase, with a smaller shift size of 2.7 cm to 14.38 cm, this occurs because in this phase it is the release stage of the remaining earthquake energy. from the koseismic phase, and in this study it was found that the postcaseismic phase still lasts up to 55 days after the earthquake. Keywords: deformation, GAMIT / GLOBK, SuGAr

Annisa, Zahratul Hilma (2020) ANALISA DEFORMASI AKIBAT GEMPA BENGKULU 2007 Mw8,5 MENGGUNAKAN DATA Sumatran GPS Array. Diploma thesis, Universitas Andalas.