THE CHANGE OF ROCK CONDITION OBSERVED BY H/V SPECTRAL AND ELLIPTICITY CURVE INVERSION ANALYSIS (CASE STUDY: PALU EARTHQUAKE SEPTEMBER 28, 2018)
Palu City is composed of sedimentary rocks so that it has a high level of vulnerability when an earthquake occurs. The earthquake that occurred on September 28, 2018, 25 km north of Donggala with a magnitude of 7.4 Mw, had caused a tsunami that struck Palu City, Sigi Regency, Donggala Regency, and P...
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Universitas Negeri Jakarta
2020-12-01
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| Series: | Spektra: Jurnal Fisika dan Aplikasinya |
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| Online Access: | https://journal.unj.ac.id/unj/index.php/spektra/article/view/16312 |
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| author | Sandy Tri Gustono Muhammad Akhadi Kekey Salsabil Azzahra Rika Adelina Ginting |
| author_facet | Sandy Tri Gustono Muhammad Akhadi Kekey Salsabil Azzahra Rika Adelina Ginting |
| author_sort | Sandy Tri Gustono |
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| description | Palu City is composed of sedimentary rocks so that it has a high level of vulnerability when an earthquake occurs. The earthquake that occurred on September 28, 2018, 25 km north of Donggala with a magnitude of 7.4 Mw, had caused a tsunami that struck Palu City, Sigi Regency, Donggala Regency, and Parigi Mouthong Regency, Central Sulawesi Province. This earthquake also caused liquefactions in the Petobo and Balaroa areas, Palu City, and Jono Oge in Sigi Regency. In this study, the authors used microtremor data at 8 points measured before and after the earthquake. Processing using the Horizontal to Vertical Spectra Ratio method shows that the predominant frequency and amplification factor changes due to changes in local rock conditions. The analysis also shows the value of soil vulnerability index (Kg) mostly increased after the earthquake. Besides, the elliptic curve inversion method shows that before the earthquake event, the value of the S wave velocity (Vs30) in layer one was between 157.1-211.4 m/sec with a layer thickness between 65.3-90.6 meters, while after the earthquake, the velocity becomes 156-214.6 m/sec with a layer thickness ranging between 66-99.2 meters. This indicates that the area consists of soft and medium soils, which subsequently increased sediment thickness in most areas after the earthquake. |
| format | Article |
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| institution | Kabale University |
| issn | 2541-3384 2541-3392 |
| language | English |
| publishDate | 2020-12-01 |
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| series | Spektra: Jurnal Fisika dan Aplikasinya |
| spelling | doaj-art-e2fa9dd37bbe45cf97ea2480a0a66a032025-08-20T03:25:15ZengUniversitas Negeri JakartaSpektra: Jurnal Fisika dan Aplikasinya2541-33842541-33922020-12-015320121210.21009/SPEKTRA.053.0412082THE CHANGE OF ROCK CONDITION OBSERVED BY H/V SPECTRAL AND ELLIPTICITY CURVE INVERSION ANALYSIS (CASE STUDY: PALU EARTHQUAKE SEPTEMBER 28, 2018)Sandy Tri Gustono0Muhammad AkhadiKekey Salsabil Azzahra1Rika Adelina Ginting2Geophysics Department, College of Meteorology Climatology and Geophysics Perhubungan 1 Street, Number 5, Pondok Betung, Pondok Aren, Tangerang Selatan City, Banten, 15221, Indonesia Geophysics Department, College of Meteorology Climatology and Geophysics Perhubungan 1 Street, Number 5, Pondok Betung, Pondok Aren, Tangerang Selatan City, Banten, 15221, Indonesia Geophysics Department, College of Meteorology Climatology and Geophysics Perhubungan 1 Street, Number 5, Pondok Betung, Pondok Aren, Tangerang Selatan City, Banten, 15221, Indonesia Palu City is composed of sedimentary rocks so that it has a high level of vulnerability when an earthquake occurs. The earthquake that occurred on September 28, 2018, 25 km north of Donggala with a magnitude of 7.4 Mw, had caused a tsunami that struck Palu City, Sigi Regency, Donggala Regency, and Parigi Mouthong Regency, Central Sulawesi Province. This earthquake also caused liquefactions in the Petobo and Balaroa areas, Palu City, and Jono Oge in Sigi Regency. In this study, the authors used microtremor data at 8 points measured before and after the earthquake. Processing using the Horizontal to Vertical Spectra Ratio method shows that the predominant frequency and amplification factor changes due to changes in local rock conditions. The analysis also shows the value of soil vulnerability index (Kg) mostly increased after the earthquake. Besides, the elliptic curve inversion method shows that before the earthquake event, the value of the S wave velocity (Vs30) in layer one was between 157.1-211.4 m/sec with a layer thickness between 65.3-90.6 meters, while after the earthquake, the velocity becomes 156-214.6 m/sec with a layer thickness ranging between 66-99.2 meters. This indicates that the area consists of soft and medium soils, which subsequently increased sediment thickness in most areas after the earthquake.https://journal.unj.ac.id/unj/index.php/spektra/article/view/16312palu earthquakemicrotremorhvsr methodseismic vulnerabilityvs30 |
| spellingShingle | Sandy Tri Gustono Muhammad Akhadi Kekey Salsabil Azzahra Rika Adelina Ginting THE CHANGE OF ROCK CONDITION OBSERVED BY H/V SPECTRAL AND ELLIPTICITY CURVE INVERSION ANALYSIS (CASE STUDY: PALU EARTHQUAKE SEPTEMBER 28, 2018) Spektra: Jurnal Fisika dan Aplikasinya palu earthquake microtremor hvsr method seismic vulnerability vs30 |
| title | THE CHANGE OF ROCK CONDITION OBSERVED BY H/V SPECTRAL AND ELLIPTICITY CURVE INVERSION ANALYSIS (CASE STUDY: PALU EARTHQUAKE SEPTEMBER 28, 2018) |
| title_full | THE CHANGE OF ROCK CONDITION OBSERVED BY H/V SPECTRAL AND ELLIPTICITY CURVE INVERSION ANALYSIS (CASE STUDY: PALU EARTHQUAKE SEPTEMBER 28, 2018) |
| title_fullStr | THE CHANGE OF ROCK CONDITION OBSERVED BY H/V SPECTRAL AND ELLIPTICITY CURVE INVERSION ANALYSIS (CASE STUDY: PALU EARTHQUAKE SEPTEMBER 28, 2018) |
| title_full_unstemmed | THE CHANGE OF ROCK CONDITION OBSERVED BY H/V SPECTRAL AND ELLIPTICITY CURVE INVERSION ANALYSIS (CASE STUDY: PALU EARTHQUAKE SEPTEMBER 28, 2018) |
| title_short | THE CHANGE OF ROCK CONDITION OBSERVED BY H/V SPECTRAL AND ELLIPTICITY CURVE INVERSION ANALYSIS (CASE STUDY: PALU EARTHQUAKE SEPTEMBER 28, 2018) |
| title_sort | change of rock condition observed by h v spectral and ellipticity curve inversion analysis case study palu earthquake september 28 2018 |
| topic | palu earthquake microtremor hvsr method seismic vulnerability vs30 |
| url | https://journal.unj.ac.id/unj/index.php/spektra/article/view/16312 |
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