Main Article Content

Abstract

ABSTRAK


 


Provinsi Bengkulu terletak di antara Sumatra Fault Zone  dan Mentawai Fault Zone, yang mana merupakan sistem patahan paling berbahaya di Pulau Sumatera, Indonesia. Selain itu, gempa bumi Bengkulu tahun 2000 dengan magnitudo sebesar Mw 7,9 menyebabkan banyak korban jiwa dan harta benda di sekitar wilayah studi, dan banyak gempa lain yang merusak yang terjadi setelah gempa ini. Penentuan zona rawan gempa Kabupaten Bengkulu Selatan penting dilakukan untuk mengurangi kerusakan akibat gempa. Oleh karena itu, perekaman data mikrotremor short period dilakukan di 65 titik di daerah penelitian. Analisis data ambient noise dapat membantu mengidentifikasi local site-efect di Kabupaten Bengkulu Selatan dengan menggunakan metode Horizontal to Vertical Spectral Ratio (HVSR). Frekuensi fundamental alami berkisar antara 1.0 Hz hingga 9.3 ​​Hz, dan faktor amplifikasi berkisar antara 1.8 hingga 4.4. Nilai PGA diperoleh dari kejadian gempa bumi selama 100 tahun dan dihitung menggunakan persamaan Kanai. Hasil menunjukkan bahwa nilai PGA berkisar antara 0.18 g hingga 0.78 g. Zona rawan gempa di Kabupaten Bengkulu Selatan terbagi menjadi tiga zona, yaitu zona klasifikasi rendah (Kota Manna, Pasar Manna, Bunga mas, dan Seginim) , sedang (Pino Raya, Air Nipis, dan Ulu Manna), dan tinggi (Manna, Kedurang, dan Kedurang Ilir). Hasil penelitian ini dapat menjadi rekomendasi bagi pemangku kepentingan untuk mempertimbangkan langkah-langkah yang tepat untuk desain dan konstruksi tahan gempa di Kabupaten Bengkulu Selatan.


 


Kata  kunci: Gempa Bumi, HVSR, Kabupaten Bengkulu Selatan, PGA.


 


ABSTRACT


 


Bengkulu Province is between the Sumatra Fault Zone and the Mentawai Fault Zone, the most dangerous fault system in Sumatra, Indonesia. In addition, the 2000 Bengkulu earthquake with a magnitude of Mw 7.9 caused a significant loss of life and property in the study area, and many other destructive earthquakes occurred after this earthquake. Determining the earthquake-prone zone of South Bengkulu Regency is essential to reducing earthquake damage. Therefore, short-period microtremor data recording was conducted at 65 points in the study area. Analysis of ambient noise data can help identify local site effects in South Bengkulu Regency using the Horizontal to Vertical Spectral Ratio (HVSR) method. The natural fundamental frequency ranges from 1.0 Hz to 9.3 Hz, and the amplification factor ranges from 1.8 to 4.4. PGA values were obtained from a 100-year earthquake event and calculated using the Kanai equation. The results show that PGA values range from 0.18 g to 0.78 g. The earthquake-prone zones in South Bengkulu Regency are divided into three zones: low (Kota Manna, Pasar Manna, Bunga Mas, and Seginim), medium (Pino Raya, Air Nipis, and Ulu Manna), and high (Manna, Kedurang, and Kedurang Ilir). The results of this study can serve as recommendations for stakeholders to consider appropriate measures for earthquake-resistant design and construction in South Bengkulu Regency.


 


Keywords: Earthquake, HVSR, South Bengkulu Regency, PGA.

Keywords

Earthquake HVSR South Bengkulu Regency PGA

Article Details

How to Cite
Kencoro, G., Farid, M., Hadi, A. I., Fadli, D. I., & Sedayu, A. (2023). ANALISIS ZONA RAWAN GEMPA BUMI DI KABUPATEN BENGKULU SELATAN BERDASARKAN PERCEPATAN TANAH PUNCAK MENGGUNAKAN FORMULA KANAI. Jurnal Kumparan Fisika, 6(2), 75–82. https://doi.org/10.33369/jkf.6.2.75-82

References

  1. Dong L, Luo Q. Investigations and New Insights on Earthquake Mechanics from Fault Slip Experiments. Earth-Science Rev. 2022;228:104019.
  2. Farid M, Mase LZ. Implementation of Seismic Hazard Mitigation on the Basis of Ground Shear Strain Indicator for Spatial Plan of Bengkulu City, Indonesia. Int J GEOMATE. 2020;18(69):199–207.
  3. Daryono, Sutikno, Sartohadi J, Brotopuspito KS, Dulbahri. Pengkajian Local Site Effect di Graben Bantul Menggunakan Indeks Kerentanan Seismik Berdasarkan Pengukuran Mikrotremor. J Kebencanan Indones. 2009;2(1):456–67.
  4. Wulandari A, Suharno, Rustadi, Robiana R. Pemetaan Mikrozonasi Daerah Rawan Gempabumi Menggunakan Metode HVSR Daerah Painan Sumatera Barat. J Geofis Eksplor. 2012;4(1):31–45.
  5. Tanjung NAF, Permatasari I, Yuniarto AHP. Analisis Peak Ground Acceleration (PGA) Kota Tegal Menggunakan Metode HVSR ( Horizontal to Vertical Spectra Ratio ). Geosaintek. 2021;7(1):9–16.
  6. Nakamura Y. A Method for Dynamic Characteristics Estimation of Subsurface using Microtremor on The Ground Surface. Railw Tech Res Institute, Q Reports. 1989;30(1):25–33.
  7. Nakamura Y. On the H/V spectrum. In: The 14th World Conference on Earthquake Engineering. Beijing, China; 2008. p. 1–10.
  8. Awaliyah IA, Hadi AI, Farid M, Fadli DI, Akbar AJ, Refrizon R. Microzonation Site Effects and Shear Strain during Earthquake Induced Landslide Using HVSR Measurement in Ulu Mana Sub-District, South Bengkulu Regency Indonesia. J Penelit Pendidik IPA. 2023;9(2):592–9.
  9. Gonzalez RE, Stephens MT, Toma C, Dowdell D. Incorporating Potential Environmental Impacts in Building Seismic Design Decisions [Internet]. Bulletin of Earthquake Engineering. Springer Netherlands; 2023. 0123456789 p. Available from: https://doi.org/10.1007/s10518-023-01686-y
  10. Falcone G, Acunzo G, Mendicelli A, Mori F, Naso G, Peronace E, et al. Seismic Amplification Maps of Italy Based on Site-Specific Microzonation Dataset and One-Dimensional Numerical Approach. Eng Geol [Internet]. 2021;289:106170. Available from: https://doi.org/10.1016/j.enggeo.2021.106170
  11. USGS. Data Katalog Gempabumi [Internet]. USGS. 2022 [cited 2022 Dec 7]. Available from: https://earthquake.usgs.gov/earthquakes/search/
  12. SESAME. Guidelines for the Implementation of the H/V Spectral Ratio Technique on Ambient Vibrations. Measurements, Processing and Interpretation. Vol. D23.12. 2004.
  13. Wathelet M, Chatelain JL, Cornou C, Giulio G Di, Guillier B, Ohrnberger M, et al. Geopsy: A User-Friendly Open-Source Tool Set for Ambient Vibration Processing. Seismol Res Lett. 2020;91(3):1878–1889.
  14. Ehsani N, Ghaemghamian MR, Fazlavi M. Estimation of Subsurface Structure using Microtremor in Karaj City , Iran. In: 10th Asian Regional conference of IAEG. Kyoto, Japan: Japan Society of Engineering Geology; 2015. p. 1–7.
  15. Nurwidyanto MI, Zainuri M, Wirasatriya A, Yulianto G. Microzonation for Earthquake Hazards with HVSR Microtremor Method in The Coastal Areas of Semarang, Indonesia. Geogr Tech. 2023;18(2):177–88.
  16. Amin TC, Kusnama., Rustandi E, Gafoer S. Peta Geologi Lembar Manna dan Enggano, Sumatera [Internet]. Pusat Survei Geologi, Badan Geologi, Kementrian Energi dan Sumber Daya Mineral. 2012 [cited 2023 Apr 1]. Available from: https://geologi.esdm.go.id/geomap/pages/preview/peta-geologi-lembar-manna-dan-enggano-sumatera
  17. Douglas J. Ground Motion Prediction Equations 1964–2021. London: Department of Civil & Environmental Engineering Imperial College London; 2021. 24 p.
  18. Manan A, Puspitafuri C, Pertiwi I, Chahyani R. Identification of Peak Ground Acceleration and hazard potency of earthquake disaster on the mainland surface of Wangi-Wangi Island, Wakatobi Regency, Southeast Sulawesi, Indonesia. J Phys Conf Ser. 2023;2498(1):012040.