Mikrozonasi Seismik Berdasarkan Data Mikrotremor Untuk Pemetaan Kerusakan Akibat Gempa Di Pulau Bawean, Gresik

Dewi, Maulida Krisna (2025) Mikrozonasi Seismik Berdasarkan Data Mikrotremor Untuk Pemetaan Kerusakan Akibat Gempa Di Pulau Bawean, Gresik. Other thesis, Sepuluh Nopember Institute of Technology.

Text 5017211050-Undergraduate_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (10MB) | Request a copy

Abstract

Pulau Bawean, Gresik, merupakan wilayah dengan tingkat kerawanan tinggi terhadap gempa bumi akibat aktivitas sesar aktif di Laut Jawa. Gempa bumi yang terjadi pada 22 Maret 2024 menyebabkan kerusakan signifikan, termasuk ribuan rumah rusak dan puluhan ribu warga mengungsi. Penelitian ini bertujuan untuk melakukan mikrozonasi seismik menggunakan data mikrotremor untuk menganalisis karakteristik tanah dan mengidentifikasi zona kerentanan terhadap guncangan gempa. Metode Horizontal to Vertical Spectral Ratio (HVSR) digunakan untuk memperoleh parameter frekuensi dominan (f0) dan amplitudo H/V (A0). Hasil analisis menunjukkan bahwa nilai f0 di Pulau Bawean berkisar antara 0.65-4.55 Hz, dengan amplitudo H/V antara 2.01 hingga 6.81 yang mencerminkan variasi kontras impedansi bawah permukaan. Nilai indeks Kg berada dalam rentang 1.04–29.54, mengindikasikan tingkat kerentanan tanah yang beragam. Nilai PGA berkisar antara 0.109–0.174 m/s2 dan nilai GSS antara 1.3 × 10⁻⁴ hingga 4.9 × 10⁻³. Dalam mengelompokkan zona berdasarkan parameter tersebut, diterapkan metode Fuzzy C-Means Clustering, yang menghasilkan tiga zona tingkat kerentanan rendah, sedang, dan tinggi. Dari 148 titik pengukuran, diperoleh peta mikrozonasi yang menunjukkan keterkaitan kuat antara nilai indeks kerentanan dan tingkat kerusakan akibat gempa. Hasil penelitian ini diharapkan dapat menjadi acuan dalam strategi mitigasi bencana, penguatan struktur bangunan, dan pengembangan tata ruang wilayah yang lebih tangguh terhadap gempa bumi.

=====================================================================================================================================
Bawean Island, located in Gresik Regency, is a region with high vulnerability to earthquakes due to the presence of active faults in the Java Sea. The earthquake that occurred on March 22, 2024, caused significant damage, including thousands of destroyed houses and the displacement of tens of thousands of residents. This study aims to conduct seismic microzonation using microtremor data to analyze soil characteristics and identify zones that are susceptible to earthquake-induced damage. The Horizontal to Vertical Spectral Ratio (HVSR) method was applied to obtain parameters such as dominant frequency (f₀) and H/V amplitude (A₀). The analysis revealed that the f₀ values across Bawean Island range from 0.65 to 4.55 Hz, with H/V amplitudes between 2.01 and 6.81, reflecting variations in subsurface impedance contrast. The seismic vulnerability index (Kg) ranges from 1.04 to 29.54, indicating diverse levels of soil susceptibility. Peak Ground Acceleration (PGA) values were found to vary between 0.109 and 0.174 m/s² and the GSS values range from 1.3 × 10⁻⁴ to 4.9 × 10⁻³. To classify the area into vulnerability zones, the Fuzzy C-Means Clustering method was employed, resulting in three zones: low, medium, and high vulnerability. A total of 148 measurement points were analyzed, producing a microzonation map that shows a strong correlation between seismic vulnerability index values and actual damage observed during the earthquake. The results of this study are expected to serve as a reference for disaster mitigation strategies, structural reinforcement, and spatial planning to enhance regional resilience against future seismic events.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	HVSR, Kerentanan Seismik, Klasterisasi Fuzzy C-Means Mikrotremor, Mikrozonasi, Fuzzy C-Means Clustering, HVSR, Microtremor, Microzonation, Seismic Vulnerability
Subjects:	Q Science > QE Geology > QE538.8 Earthquakes. Seismology Q Science > QE Geology > QE539 Microseisms.
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Geophysics Engineering > 33201-(S1) Undergraduate Thesis
Depositing User:	Maulida Krisna Dewi
Date Deposited:	31 Jul 2025 03:47
Last Modified:	31 Jul 2025 03:47
URI:	http://repository.its.ac.id/id/eprint/123995

Actions (login required)

View Item