Pemodelan Deformasi Gunung Sinabung Untuk Memprediksi Posisi Pusat Tekanan Magma Dengan Model Yokoyama Menggunakan Data Citra SAR Metode PS-InSAR

Abstract

Deformation Modeling Predicate The Position Of The Magma Pressure Center Model Abstract: Indonesia is a tectovolcanic country with 129 active volcanoes. The existence of a volcano certainly has a positive impact, such as the area around the mountain becomes fertile and has a negative impact due to frequent disasters. One of the active volcanoes in Indonesia is Mount Sinabung. The existence of magma activity in active volcanoes causes changes in shape due to the movement and shift of the soil on the surface of the volcano which is called deformation. Deformation can be determined by terrestrial methods using theodolite, land Sipat and extra-terrestrial methods with GPS observations and processing of SAR image data using InSAR, D-InSAR, MT-InSAR processing methods which include, PS-InSAR and SBAS. This research was conducted to determine the deformation that occurs in the Sinabung volcano using the PS-InSAR method followed by modeling the position of the magma compression source using the Yokoyama model. The Yokoyama model assumes that the Earth's crust is composed of elastic spaces, and the source of the pressure is a small spherical space with hydrostatic pressure that is unidirectional and its expansion is radial. The SAR data used consists of 7 ascending acquisition images and 8 descending acquisition images on the acquisition date of October 1 to December 31, 2020. By processing the image in ascending and descending ways, the LOS velocity rate can be transformed into horizontal and vertical shift values. The results of PS-InSAR processing show that the LOS velocity rate ranges from 394.1 mm/year to 320.7 mm/year in the ascending direction and in descending direction, the LOS velocity rate ranges from -277.5 mm/year to 31.5.8 mm/year. After decomposing the LOS velocity rate, the displacement value of the PS point in the horizontal and vertical directions at the PS1 point is (0.288; -0.037) meters, the PS2 point is (0.004; 0.010) meters and the PS3 point is (0.041, -0.084) meters. So that the position of the center of magma pressure using the horizontal shift value on Mount Sinabung based on the Yokoyama model is located at coordinates