Studi Seismotektonik Dan Kerentanan Seismik Wilayah Karo Dengan Double-Difference Dan Horizontal Vertical Spectra Ratio

Marbun, Nesia Sabrina (2026) Studi Seismotektonik Dan Kerentanan Seismik Wilayah Karo Dengan Double-Difference Dan Horizontal Vertical Spectra Ratio. Masters thesis, Institut Teknologi Sepuluh Nopember.

Text 6009232004-Master_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (4MB) | Request a copy

Abstract

Pulau Sumatera merupakan wilayah rawan gempa bumi yang dikontrol oleh tektonik lempeng Indo-Australia dan Eurasia. Di Sumatera Utara, 75% kejadian gempa bumi berasosiasi dengan Sesar Renun, Toru, dan Angkola. Beberapa kejadian gempa signifikan terjadi di luar zona patahan yang belum terpetakan, seperti gempa Karo tahun 2017 dan aktivitas gempa swarm Samosir pada periode 2022-2023, yang mengindikasikan keberadaan struktur patahan aktif baru. Penelitian ini bertujuan untuk menganalisis karakteristik seismotektonik dan tingkat kerentanan seismik wilayah Karo, Sumatera Utara, menggunakan metode relokasi DoubleDifference dan Horizontal to Vertical Spectral Ratio (HVSR). Relokasi hiposenter berhasil dilakukan terhadap 428 kejadian gempa lokal dan penurunan nilai RMS (e) menjadi < 0.5. Hasil relokasi memperlihatkan klaster hiposenter yang lebih jelas pada kedalaman sekitar 5–15 km, dengan beberapa klaster menunjukkan kecenderungan bidang berarah barat-laut - tenggara dan timur-laut - barat-daya. Analisis HVSR pada sejumlah titik pengukuran menunjukkan nilai frekuensi dominan (f₀) berkisar antara sekitar 0,8-4,0 Hz dengan faktor amplifikasi (A) sekitar 2-6 mengindikasikan keberadaan sedimen dangkal dan potensi penguatan gelombang seismik. Integrasi hasil relokasi Double-Difference dan parameter HVSR mengidentifikasi beberapa zona dengan kerentanan seismik tinggi, khususnya pada area dengan frekuensi dominan rendah (<1,5 Hz) dan nilai amplifikasi tinggi (>4).
==============================================================================================================================
Sumatra Island is an earthquake-prone region due to tectonic activity along the boundary between the Indo-Australian and Eurasian Plates. In North Sumatra, 75% of earthquake events are associated with the Renun, Toru, and Angkola Faults. Several significant earthquake events occurred outside the unmapped fault zone, such as the 2017 Karo earthquake and the Samosir swarm activity in 2022-2023, indicating the presence of new active fault structures. This study aims to analyze the seismotectonic characteristics and seismic vulnerability levels of the Karo region, North Sumatra, using the Double-Difference and Horizontal-to-Vertical Spectral Ratio (HVSR) relocation methods. Hypocenter relocation was successfully carried out for 428 local earthquake events, reducing the RMS (e) value to <0.5. The relocation results show clearer hypocenter clusters at depths of approximately 5–15 km, with some clusters showing a northwest-southeast and northeast-southwest trending plane. HVSR analysis at several measurement points shows dominant frequency (f₀) values ranging from approximately 0.8 to 4.0 Hz, with amplification factors (A) of approximately 2 to 6, indicating shallow sediments and potential seismic wave amplification. Integration of Double-Difference relocation results and HVSR parameters identifies several zones with high seismic vulnerability, particularly in areas with low dominant frequencies (<1.5 Hz) and high amplification (>4).

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Relokasi, Double-Difference, Seismotektonik, Kerentanan Seismik, Wilayah Karo, HVSR, Gempa Bumi. Relocation, Double-Difference, Seismotectonics, Seismic Vulnerability, Karo Region, HVSR, Earthquake.
Subjects:	Q Science > QE Geology > QE538.8 Earthquakes. Seismology
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Physics Engineering > 30101-(S2) Master Thesis
Depositing User:	Nesia Sabrina Marbun
Date Deposited:	12 Feb 2026 04:01
Last Modified:	12 Feb 2026 04:08
URI:	http://repository.its.ac.id/id/eprint/132363

Actions (login required)

View Item