Analisis Volume Suplai Magma Dan Hubungannya Dengan Intensitas Seismik Gunung Merapi Pada Periode 2022-2024

Aziz, Farah (2025) Analisis Volume Suplai Magma Dan Hubungannya Dengan Intensitas Seismik Gunung Merapi Pada Periode 2022-2024. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Gunung Merapi, gunungapi strato-vulkano yang berlokasi di perbatasan Provinsi Jawa Tengah dan Daerah Istimewa Yogyakarta, merupakan salah satu gunung berapi paling aktif di dunia. Aktivitas vulkanik yang tinggi menunjukkan adanya akumulasi atau pergerakan magma di dalam tubuh gunung. Pemantauan deformasi (perubahan bentuk gunungapi) menggunakan metode Electronic Distance Measurement (EDM) memungkinkan dilakukannya upaya mitigasi. Pengukuran secara episodik menghasilkan perubahan jarak tunjam atau Change Slope Distance (CSD), yang mengindikasikan terjadinya deformasi pada instrumen pengukuran. Penelitian ini menggunakan 17 baseline EDM untuk menentukan parameter penyebab deformasi, yaitu karakteristik sumber tekanan (lokasi dan ukuran kantong magma) yang diasumsikan berbentuk bola (spherical pressure source), intensitas tekanan yang menyebabkan inflasi, serta volume dan laju suplai magma selama periode 1 Juni 2022 hingga 31 Desember 2024. Metode grid search diterapkan untuk menemukan residual terkecil antara hasil pengukuran lapangan dan perhitungan teoretis. Hasil penelitian menunjukkan bahwa selama periode 1 Juni 2022 hingga 31 Desember 2024, deformasi yang terjadi bersifat asimetris akibat pergerakan kubah lava 1888 sejauh 4,24 meter ke arah barat laut. Estimasi karakteristik sumber tekanan menunjukkan ukuran kantong magma sekitar 207,31 meter pada kedalaman 1.100 hingga 1.700 meter di bawah puncak, konsisten dengan zona aseismik. Tekanan yang menyebabkan inflasi bersifat fluktuatif, berkisar antara 0,9 hingga 35 MPa. Selama periode penelitian, volume suplai magma bertambah sebesar 9,31 × 106 m3 dengan laju fluktuatif antara 0,8 – 115 × 103 m3 per hari. Peningkatan laju suplai magma berkorelasi dengan intensitas aktivitas seismik yang tercermin pada gempa Vulkano-Tektonik A (VTA), Vulkano-Tektonik B (VTB), dan Multiphase (MP). Data seismik berfungsi sebagai validator untuk memastikan bahwa deformasi yang terukur berkaitan dengan aktivitas vulkanisme. Hasil penelitian ini diharapkan dapat dijadikan acuan bagi pemangku kebijakan dalam upaya mitigasi risiko bencana di masa mendatang.
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Mount Merapi, a stratovolcano located on the border between Central Java Province and the Special Region of Yogyakarta, is one of the most active volcanoes in the world. Its high volcanic activity indicates the accumulation or movement of magma within the volcanic body. Deformation monitoring (changes in the volcano's shape) using the Electronic Distance Measurement (EDM) method allows for mitigation efforts. Episodic measurements yield changes in Slope Distance (CSD), which indicate deformation in the measurement instruments. This study utilized 17 EDM baselines to determine the parameters causing deformation, including the characteristics of the pressure source (the location and size of the magma chamber), which is assumed to be spherical, the pressure intensity causing inflation, and the volume and magma supply rate during the period from June 1, 2022, to December 31, 2024. The grid search method was applied to find the smallest residual between field measurement results and theoretical calculations. The results show that during the study period, the deformation was asymmetric due to the movement of the 1888 lava dome, which shifted 4.24 meters northwest. The estimated characteristics of the pressure source reveal a magma chamber approximately 207.31 meters in size, located at a depth of 1 100 to 1 700 meters beneath the summit, consistent with the aseismic zone. The pressure causing inflation fluctuated between 0.9 and 35 MPa. Throughout the study period, the magma supply volume increased by 9.31 × 106 m3, with a fluctuating rate ranging from 0.8 to 115 × 103 m3 per day. The increase in magma supply rate correlates with the intensity of seismic activity, reflected in the occurrence of Volcano-Tectonic A (VTA), Volcano-Tectonic B (VTB), and Multiphase (MP) earthquakes. Seismic data serve as a validator to confirm that the measured surface deformation is related to volcanic activity. These findings are expected to serve as a reference for policymakers in disaster risk mitigation efforts in the future.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Gunung Merapi, Deformasi, Electronic Distance Measurement (EDM), Spherical Pressure Source, Volume Suplai Magma, Mount Merapi, Deformation, Electronic Distance Measurement (EDM), Spherical Pressure Source, Magma Supply Volume
Subjects:	Q Science > QE Geology > QE604 Deformation
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Geophysics Engineering > 33201-(S1) Undergraduate Thesis
Depositing User:	Farah Aziz
Date Deposited:	29 Jul 2025 04:08
Last Modified:	29 Jul 2025 04:11
URI:	http://repository.its.ac.id/id/eprint/122557

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