Analisis Anomali Ionosfer Akibat Gempa Bumi dan Ledakan Bom dengan Menggunakan Model 3D Tomografi

Purwanto, Fira Anggielia (2025) Analisis Anomali Ionosfer Akibat Gempa Bumi dan Ledakan Bom dengan Menggunakan Model 3D Tomografi. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Ionosfer merupakan lapisan atmosfer yang kaya akan elektron dan ion, terletak pada ketinggian 60-1000 km di atas permukaan bumi. Gangguan pada ionosfer dapat dipicu oleh fenomena alami seperti gempa bumi maupun aktivitas antropogenik seperti ledakan bom dan serangan udara. Penelitian ini bertujuan untuk menganalisis dampak dari aktivitas tersebut terhadap perubahan TEC. Salah satu fokus utama dalam studi ini adalah fenomena CID, yakni perubahan signifikan TEC setelah kejadian impulsif. Studi kasus dilakukan pada empat peristiwa utama, yaitu gempa bumi M7.1 di Laut Hyuganada, Jepang, ledakan bom di Tartus, Suriah, serta dua serangan udara terhadap fasilitas nuklir di Iran yang dilakukan oleh Israel dan Amerika Serikat. Data observasi dari Global Navigation Satellite System (GNSS) pada stasiun CORS digunakan untuk menghitung nilai TEC dan menentukan lintasan SIP. Anomali TEC diidentifikasi menggunakan metode polynomial fitting orde tinggi untuk memisahkan tren normal dari gangguan. Selanjutnya, dilakukan pemodelan 3D tomografi untuk mengamati distribusi spasial dan temporal gangguan ionosfer serta menghitung kecepatan propagasi gelombang berdasarkan hubungan regresi linier antara waktu puncak ∆TEC dan jarak SIP ke pusat kejadian. Hasil penelitian menunjukkan bahwa keempat peristiwa menghasilkan CID dengan karakteristik berbeda. Gempa Jepang menunjukkan pola TEC bipolar dengan waktu kemunculan CID 13–14 menit dan amplitudo rendah. Ledakan Tartus menghasilkan lonjakan ∆TEC dominan positif dengan amplitudo hingga 17 TECU dan CID muncul 26–29 menit setelah kejadian. Serangan udara Iran menunjukkan variasi pola dari bipolar lemah hingga dominan positif, dengan amplitudo hingga 5,9 TECU dan waktu kemunculan 11–34 menit. Sementara itu, serangan udara oleh Amerika Serikat memunculkan anomali TEC fluktuatif dengan CID 8–19 menit dan amplitudo tertinggi mencapai 11,041 TECU. Kecepatan propagasi CID bervariasi dari 0,124 hingga 10,078 km/s, yang mengindikasikan keterlibatan gelombang akustik, gravitasi, dan kemungkinan artefak estimasi. Penelitian ini memperkuat pemahaman tentang interaksi antara aktivitas permukaan dan ionosfer serta berpotensi mendukung sistem mitigasi bencana berbasis GNSS.
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The ionosphere is a layer of the atmosphere that is rich in electrons and ions, located at an altitude of 60–1000 km above the Earth's surface. Disturbances in the ionosphere can be triggered by natural phenomena such as earthquakes or anthropogenic activities such as bomb explosions and airstrikes. This study aims to analyze the impact of these activities on changes in TEC. One of the main focuses of this study is the phenomenon of CID, which refers to significant changes in TEC following impulsive events. Case studies were conducted on four major events, namely the M7.1 earthquake in the Hyuganada Sea, Japan; the bomb explosion in Tartus, Syria; and two airstrikes on nuclear facilities in Iran carried out by Israel and the United States. Observation data from the Global Navigation Satellite System (GNSS) at CORS stations were used to calculate TEC values and determine the trajectory of the SIP. TEC anomalies were identified using a high-order polynomial fitting method to separate normal trends from disturbances. Furthermore, 3D tomography modeling was carried out to observe the spatial and temporal distribution of ionospheric disturbances and to calculate wave propagation velocity based on the linear regression relationship between the ∆TEC peak time and the distance from the SIP to the event center. The results showed that all four events generated CID with different characteristics. The Japanese earthquake showed a bipolar TEC pattern with CID appearing 13–14 minutes after the event and low amplitude. The Tartus explosion generated a dominant positive ∆TEC surge with an amplitude of up to 17 TECU, and CID appeared 26–29 minutes after the event. The Iranian airstrike showed varying patterns from weak bipolar to dominant positive, with amplitudes of up to 5.9 TECU and CID appearing 11–34 minutes after the event. Meanwhile, the airstrike by the United States produced fluctuating TEC anomalies with CID appearing 8–19 minutes after the event and the highest amplitude reaching 11.041 TECU. The propagation speed of the CID ranged from 0.124 to 10.078 km/s, indicating the involvement of acoustic waves, gravity waves, and possible estimation artifacts.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	gempa bumi, ledakan bom, serangan udara, ionosfer, TEC, Coseismic Ionospheric Disturbances (CID), 3D tomografi, GNSS, earthquakes, bomb blasts, air strikes, ionosphere, TEC, Coseismic Ionospheric Disturbances (CID), 3D tomography, GNSS.
Subjects:	G Geography. Anthropology. Recreation > GE Environmental Sciences Q Science > QE Geology Q Science > QE Geology > QE538.5 Seismic tomography; Seismic waves. Elastic waves Q Science > QE Geology > QE538.8 Earthquakes. Seismology Q Science > QE Geology > QE539.2 Seismic traveltime inversion Q Science > QE Geology > QE539.2.S4 Seismic models
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Geomatics Engineering > 29202-(S1) Undergraduate Thesis
Depositing User:	Fira Anggielia Purwanto
Date Deposited:	23 Jul 2025 05:51
Last Modified:	23 Jul 2025 05:51
URI:	http://repository.its.ac.id/id/eprint/120492

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