CHARACTERIZATION OF TELUK SEPANG COASTAL LOCAL SEISMIC RESPONSE USING MICROTREMOR HVSR ANALYSIS
DOI:
https://doi.org/10.23960/jge.v12i1.510Keywords:
Amplification, Dynamic soil, HVSR, Microtremor, Seismic vulnerabilityAbstract
The coastal area of Teluk Sepang, Bengkulu City, Sumatra, Indonesia, is dominated by young alluvial and marine sediments that are highly susceptible to seismic wave amplification due to tectonic activity along the Indo-Australian–Eurasian subduction zone. This research aims to characterize local seismic response and map soil dynamic properties using microtremor data analyzed with the Horizontal to Vertical Spectral Ratio (HVSR) method. Microtremor measurements were conducted at several observation points with a sampling interval of 5 ms capable of and a recording duration of 30 minutes at each site. The recorded data were processed using the HVSR method through windowing, Fourier transform, and spectral ratio analysis to obtain the dominant frequency (f₀), amplification factor (A₀), and seismic vulnerability index (Kg). The results show that low f₀ values are associated with thick soft sediments, while high A₀ values indicate stronger amplification potential. High Kg values are identified in areas where low f₀ coincides with high A₀, reflecting greater seismic vulnerability. These results reveal significant spatial variability in local seismic response across the study area. This study provides new site-specific insights into seismic vulnerability in coastal environments and contributes to improving seismic hazard assessment and coastal development planning in Bengkulu City.
References
Ariyanto, A., Farduwin, A., Styawan, Y., Putri, I. A., Junian, W. E., Prasetyo, N., Rizki, R., & Wulandari, R. (2024). Seismic Vulnerability Mapping Through HVSR Microtremor Analysis in The Kemiling District Area and Its Surroundings. Jurnal Geofisika Eksplorasi, 9(2), 82–99. https://doi.org/10.23960/ jge.v9i2.393
Bonnefoy-Claudet, S., Cotton, F., & Bard, P. Y. (2006). The Nature of Noise Wavefield and Its Applications For Site Effects Studies: A Literature Review. Earth-Science Reviews, 79(3–4), 205–227. https://doi.org/10.1016/ j.earscirev.2006.07.004
Castellaro, S. & Mulargia, F. (2009). Vs30 Estimates Using Constrained H/V Measurements. Bulletin of the Seismological Society of America, 99(2A), 761–773. https://doi.org/10.1785/0120080027
Fatimah, I., Mase, L. Z., Widiyantoro, S., & Irsyam, M. (2022). Estimation of Seismic Vulnerability Index and Site Characterization Using Microtremor HVSR Analysis. Geotechnical and Geological Engineering, 40(3), 1285–1301. https://doi.org/10.1007/ s10706-021-01986-2
Falah, M. F., Mukti, M. M., Ismawan, & Helmi, F. (2023). Geological Characteristics and Seismic Implications of Coastal Sedimentary Deposits in Bengkulu City, Indonesia. Journal of Geoscience and Engineering, 10(2), 85–96.
Farduwin, A., Nugraha, P., Styawan, Y., Lestari, E. Y. P., & Julyanti, D. P. (2025). Site Effects Identification Using HVSR Method in Cisarua Hot Spring Area, Natar, South Lampung. Jurnal Geofisika Eksplorasi, 11(2), 151–162. https://doi.org/10.23960/jge.v11i2.494
Harlianto, D., Nugraha, A. D., Widiyantoro, S., & Irsyam, M. (2024). Seismotectonic Characteristics of The Sumatra Subduction Zone and Its Implication For Seismic Hazard. Geophysical Journal International, 238(1), 112–129. https://doi.org/10.1093/gji/ ggae123
Hesti, Suharno, Mulyasari, R., & Hidayatika, A. (2021). Analysis of Subsurface Conditions Characteristics Based on Microtremor Data in The Area of The University of Lampung Teaching Hospital. Jurnal Geofisika Eksplorasi, 7(2), 150–159. https://doi.org/ 10.23960/jge.v7i2.123
Issaadi, A., Semmane, F., & Yelles-Chaouche, A. (2020). Site Characterization Using Microtremor H/V Spectral Ratio and Its Relationship With Shear-Wave Velocity. Arabian Journal of Geosciences, 13, 812. https://doi.org/10.1007/s12517-020058 12-7
Kencoro, D. R., Mase, L. Z., & Nugroho, H. (2023). Seismic Microzonation Based on HVSR and Vs30 Analysis in Urban Areas of Indonesia. Journal of Engineering and Technological Sciences, 55(3), 456–470.
Mase, L. Z., Irsyam, M., & Widiyantoro, S. (2021). Seismic Microzonation Using Microtremor HVSR and Geotechnical Data Integration. Soil Dynamics and Earthquake Engineering, 148, 106827. https://doi.org/10.1016/ j.soildyn.2021.106827
Nakamura, Y. (1989). A Method For Dynamic Characteristics Estimation of Subsurface Using Microtremor on The Ground Surface. Quarterly Report of Railway Technical Research Institute, 30(1), 25–33.
Parolai, S., Bormann, P., & Milkereit, C. (2002). New Relationships Between Vs, Thickness of Sediments, and Resonance Frequency Calculated By The H/V Ratio of Seismic Noise for The Cologne Area (Germany). Bulletin of The Seismological Society of America, 92(6), 2521–2527. https://doi.org/10.1785/ 0120010248
SESAME Project (2004). Guidelines for The Implementation of The H/V Spectral Rasio Technique on Ambient Vibrations: Measurements, Processing and interpretation. European Commission—Research General Directorate.
Siagian, S., Refrizon, & Hadi, A. I. (2025). Mapping of Natural Frequency, Amplification, Seismic Vulnerability, and Vs30 Velocity in Selebar District, Bengkulu City. Jurnal Fisika, 15(1), 20–29. https://journal.unnes.ac.id/journals/jf/article/view/16138
Simanjuntak, A. V. H., Mase, L. Z., & Widodo, A. (2021). Seismic Vulnerability Index Analysis Based on HVSR Method For Earthquake Hazard Mitigation. International Journal of Geomate, 20(78), 13–20.
Stephenson, W. J. (2007). Using Surface Waves and Microtremor Methods To Estimate Site Response. Engineering Geology, 91(1), 1–12. https://doi.org/10.1016/j.enggeo.2006.10.002
Susilo, A., Zulaikah, S., Fauzi, A., Ilham, Ma'muri, Wirawan, K., & Hasan, M. F. R. (2024). Microtremor Based Site Characterization and Seismic Response Analysis in Coastal Sedimentary Environments. Kuwait Journal of Science, 53(1), 100486. https://doi.org/10.1016/j.kjs.2025.100486
Tawakal, M. I., Mase, L. Z., & Nugraha, A. D. (2020). Site Effect Analysis Using HVSR and MASW Methods For Seismic Hazard Assessment. Journal of Applied Geophysics, 181, 104135. https://doi.org/10.1016/ j.jappgeo.2020.104135
Wathelet, M., Chatelain, J. L., Cornou, C., Giulio, G. D., Guillier, B., Ohrnberger, M., & Savvaidis, A. (2020). Geopsy: A User-Friendly Open-Source Tool Set For Ambient Vibration Processing. Seismological Research Letters, 91(3), 1878–1889. https://doi.org/10.1785/ 0220190360
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