scholarly journals ANALISIS KETEBALAN LAPISAN SEDIMEN DAN INDEKS KERENTANAN SEISMIK KOTA JAMBI BAGIAN TIMUR

2020 ◽  
Vol 6 (1) ◽  
pp. 18-30
Author(s):  
Arie Satria ◽  
Ichy Lucya Resta ◽  
Nasri MZ
Keyword(s):  
Layer Thickness ◽  
Natural Frequency ◽  
Seismic Vulnerability ◽  
Amplification Factor ◽  
Vulnerability Index ◽  
Research Area ◽  
Ratio Method ◽  
Sediment Layer ◽  
Alluvial Deposits ◽  
High Zone

A Research was carried about analysis of sediment layer thickness and seismic vulnerability index in eastern Jambi City. The purpose of this research was to  determine the effect of sediment layer thickness on seismic vulnerability index in eastern Jambi City based on microtremor data. The Acquisition data of microtremor is 25 points spread in research area. Processing data was carried out using the HVSR (Horizontal to Vertical Spectra Ratio) method to obtain the H/V curve. This curve represents the value of the natural frequency (f0) and amplification factor (A0). Based on the results of data processing obtained, the range of natural frequency (f0) value is 1.04 – 3.78 Hz, the range of amplification factor (A0) value is 1.13 - 4.88 times, the range of sediment layer thickness (h) value is 16.46 – 61.45 meters, and the range of seismic vulnerability index (Kg) value is 0.70 - 20.18×10-6 cm2/s. The results showed that the distribution of seismic vulnerability index (Kg) correlated relatively well with sediment layer thickness of the research area. The high zone of seismic vulnerability index (Kg) is relatively associated with alluvial deposits and also the sediment layer thickness of more than 30 meters. The high zone of seismic vulnerability index (Kg) is concentrated in Pasir Panjang, Tanjung Raden to Olak Kemang in Danau Teluk sub-district and Tanjung Sari in Jambi Timur sub-district.

scholarly journals THE CHANGE OF ROCK CONDITION OBSERVED BY H/V SPECTRAL AND ELLIPTICITY CURVE INVERSION ANALYSIS (CASE STUDY: PALU EARTHQUAKE SEPTEMBER 28, 2018)

2020 ◽  
Vol 5 (3) ◽  
pp. 201-212
Author(s):  
Sandy Tri Gustono ◽  
Muhammad Akhadi ◽  
Kekey Salsabil Azzahra ◽  
Rika Adelina Ginting
Keyword(s):  
Layer Thickness ◽  
Vulnerability Index ◽  
Ratio Method ◽  
Inversion Method ◽  
S Wave ◽  
Before And After ◽  
High Level ◽  
Inversion Analysis ◽  
Central Sulawesi

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.

scholarly journals Vulnerability Of The Garut District Region In Tarogong Kalam, Tarogong Kidul, Garut Kota, And Karang Pawitan Sub-District Based On Microtremor Measurement

2020 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Rahmat Setyo Yuliatmoko
Keyword(s):  
Seismic Vulnerability ◽  
Vulnerability Index ◽  
Dominant Frequency ◽  
Mitigation Measures ◽  
Ratio Method ◽  
Tectonic Earthquake ◽  
Wave Amplification ◽  
Geological Conditions ◽  
Microtremor Measurement ◽  
The Impact

The Tasikmalaya M 7.3 earthquake on September 2, 2009 had an impact on Garut, damaged infrastructure and claimed many lives. From the search results there were five areas that were severely damaged by tectonic earthquake shocks, which included Pemeungpeuk, Cisompet, Cikelet, Peundeuy and Banjarwangi Subdistricts, so that earthquake mitigation measures were needed. One of the mitigations that can research how the impact is if the potential for earthquake disasters occur below the southern surface of Java. The final objective of this research is to map disaster-prone zones in Tarogong Kaler, Tarogong Kidul, Garut City, and Karang Pawitan, Garut Subdistrict, based on dominant frequency values, Vs30, seismic vulnerability indexes, and GSS (Ground Shear Strains) so that they can know the land movement that is. Retrieval of data in this study by measuring geophysicaly methods in the field. Processing data using HVSR (Horizontal to Vertical Spectra Ratio) method, then mapped with ArcGis to interpret the zoning of the study area. Based on the research, we known that the dominant frequency distribution value is between 1-5.2 Hz. The seismic vulnerability index values calculated the study area are between 3 – 45, GSS values in the study area between 3 ×10-4 - 42×10-4. By looking at the spatial distribution of the values of f0, Kg and GSS the areas of Karangmulya, Jatiasih, Sidanggalih and Godog villages are types of young volcanic sediments classified as soft soils that are easily to wave amplification and earthquake vibrations, so that they are easily damaged during large earthquakes. in this region qualify as earthquake resistant buildings to minimize damage and losses, while Sukabakti, Kersamenak, Sukajaya, and Mekargalih villages in the west with the geological conditions of the surrounding area which is hard land so that it will be safer when an earthquake occurs.

scholarly journals Ambient Noise Analysis During Nyepi in Denpasar Using Horizontal-to-Vertical Spectral Ratio (HVSR) Method

2020 ◽  
Vol 18 (1) ◽  
pp. 23
Author(s):  
I Putu Dedy Pratama ◽  
Dwi Karyadi Priyanto ◽  
Pande Komang Gede Arta Negara
Keyword(s):  
Ambient Noise ◽  
Seismic Vulnerability ◽  
Amplification Factor ◽  
Noise Analysis ◽  
Spectral Ratio ◽  
Vulnerability Index ◽  
Dominant Frequency ◽  
Before And After ◽  
Hvsr Method ◽  
Index Value

Nyepi Day is a unique tradition where outdoor human activities stop 24 hours a day. Denpasar City is the region that has the most significant impact on this change because it is the capital province. This study aims to determine the effect of Nyepi on ambient noise in Denpasar on March 25, 2020. We installed a TDS sensor at the Denpasar Geophysics Station for 3x24 hours ie when Nyepi Day, before and after Nyepi as comparative data. The data is processed by the HVSR method to get the value of dominant frequency and amplification factor every hour. Compared to the day before and after Nyepi, the dominant frequency increased during Nyepi and the amplification factor decreased during Nyepi. Seismic vulnerability index value at Nyepi is 24 where there is a decrease of index 3,904 with a day before and after Nyepi. This is showed that Nyepi Day affected ambient noise in Denpasar.

scholarly journals Analysis of Earthquakes Potential Damages as a Disaster Mitigation Effort

2021 ◽  
Vol 2 (1) ◽  
pp. 20-23
Author(s):  
Alen Fezi Loveka ◽  
Henny Johan ◽  
Rendy W. Wardana
Keyword(s):  
Shear Strain ◽  
Seismic Vulnerability ◽  
Vulnerability Index ◽  
Disaster Mitigation ◽  
Sediment Layer ◽  
Residential Areas ◽  
Literature Study ◽  
Geological Conditions ◽  
Potential Damage ◽  
Mitigation Effort

Muara Bangkahulu District is one of Bengkulu Province Subdistricts, which is used as a place for higher education service centers, government office centers, and community residential areas. Muara Bangkahulu has the risk of being affected by an earthquake caused by its geological conditions. To avoid the potential damage due to earthquake, the PGA parameters, seismic vulnerability index, ground shear strain, and thickness of sediment layer (h) were analyzed in Muara Bangkahulu District as an effort to mitigate earthquakes. The purpose of this study is to describe the potential damage caused by the earthquake in Muara Bangkahulu District as a disaster mitigation effort. This research was a qualitative descriptive study using the literature study method. The results of the literature study which showed the value of PGA produced between 184.22 gal to 532.92 gal. Distribution of seismic vulnerability index values between 0.56 to 7.95. Distribution of ground shear strain values between 5.14 x10-5 to 7.42 x10-4. The thickness of the sediment layer (h) ranged from 8.13 meters to 61.31 meters. The largest PGA, IKS, GSS and h values are in Kualo Beach which is estimated to have a high level of risk for earthquake disasters with a correlation more than 74%. Thus, it can be concluded that the vicinity of Kualo Beach is the most potential and prone to earthquake damage.

scholarly journals LOCAL GEOLOGY AND SITE CLASS ASSESSMENT BASED ON MICROTREMOR DATA IN NORTH LOMBOK

2021 ◽  
Vol 4 (2) ◽  
pp. 67
Author(s):  
Suhayat Minardi ◽  
Nirmala Aprianti ◽  
Akhmad Solikhin
Keyword(s):  
Seismic Vulnerability ◽  
Site Effect ◽  
Vulnerability Index ◽  
Dominant Frequency ◽  
Sediment Layer ◽  
Local Site Effect ◽  
Site Class ◽  
The North ◽  
Local Site ◽  
Dominant Period

Lombok Island is an active seismic area in Indonesia potentially hit by an earthquake due to located between two earthquake generators from the south and the North. Several large earthquakes rocked Lombok, an earthquake with a magnitude of 6.4 on July 29, 2018, and 7.0 on August 5, 2018. This study aims to determine the characteristics of the local site effect based on the dominant frequency value ( ), soil amplification ( ), sediment layer thickness (d), , dominant period (T0), and seismic vulnerability index ( ) and to comprehend the soil class (site class) based on the thickness of the sediment layer (d), and  in the North Lombok region. The data used is secondary data from microtremor signal recordings in North Lombok Regency in 2018. Data processing used Geopsy software, and microtremor data were analyzed using the HVSR method. From processing the HVSR data, the dominant frequency value about (0.8 - 18) Hz, amplification value (1.7 – 9.7), dominant period value (0.05 – 1.2) seconds, seismic vulnerability index value (0.4 – 71) , and the value of   in the study area (20.05 – 287.04) m/s. Based on microtremor analysis, the local site effect indicates that alluvium rocks caused stronger earthquake vibrations and more damage. Whereas the Kalibabak and Lekopiko formations caused fewer earthquake vibrations and less wear. Based on the dominant period and , area study classify as Site Class IV class E and Site Class III class D  Copyright © 2021 IPR. All rights reserved.

scholarly journals Microzonation of Probolinggo Fault Using Microtremor as an Effort for Earthquake Disaster Mitigation

2021 ◽  
Vol 936 (1) ◽  
pp. 012026
Author(s):  
Juan Pandu Gya Nur Rochman ◽  
Amien Widodo ◽  
Dwa Desa Warnana ◽  
Wien Lestari ◽  
Mariyanto ◽  
...  
Keyword(s):  
Natural Frequency ◽  
Seismic Wave ◽  
Seismic Vulnerability ◽  
Active Fault ◽  
Vulnerability Index ◽  
Disaster Mitigation ◽  
Geophysical Method ◽  
Western Area ◽  
Microtremor Measurements ◽  
Measurement Area

Abstract Earthquake can be caused by several things, one of which is due to an active fault. To mitigate earthquake disasters that can be caused by the Probolinggo Fault, measurement of the microtremor geophysical method is carried out to analyze seismic vulnerability. In this study, the microtremor measurements were carried out on 30 measurement points. The data obtained from measurements are then processed using EasyHVSR software to obtain natural frequency (f0) and natural amplification (A0) values. This value is then used to create a microtremor microzonation map, which is seismic vulnerability index, based on natural frequency and amplification . it founded that low natural frequency mostly founded on eastern of measurement area, caused by thick sedimentary from Lamongan volcanic. High amplification mostly founded from middle to western area, and high seismic vulnerability index founded on western of measurement area, include Maron and Krucil Sub-district. It means seismic wave can very destructive on those area.

scholarly journals INDEK KERENTANAN DAN AMPLIFIKASI TANAH AKIBAT GEMPA DI WILAYAH UNIVERSITAS MUHAMMADIYAH JEMBER

2015 ◽  
Vol 12 (2) ◽  
Author(s):  
Muhtar . ◽  
Arief Alihudien
Keyword(s):  
Seismic Vulnerability ◽  
Multicriteria Analysis ◽  
Vulnerability Index ◽  
Research Area ◽  
Disaster Mitigation ◽  
Mitigation Measures ◽  
Land Values ◽  
Soil Amplification ◽  
Residential Areas ◽  
The Impact

INDEK KERENTANAN DAN AMPLIFIKASI  TANAH AKIBAT GEMPA DI  WILAYAH UNIVERSITAS MUHAMMADIYAH JEMBERVulnerability and Soil Amplification Index Due to Earthquake in The University Muhammadiyah JemberMuhtar1 & Arief Alihudien21Jurusan Teknik Sipil Fakultas Teknik – Universitas Muhammadiyah Jember2Jurusan Teknik Sipil Fakultas Teknik – Universitas Muhammadiyah JemberAlamat Korespondensi : Perum Taman Bambu B-01 Jember 68124Email : 1)[email protected] phenomena of earthquakes until now could not be predicted and the exact time it happened. Earthquake danger can not be avoided but its impact can be reduced through assessment activities characteristic earthquakes in a region that will be applied in the selection of methods and policies for disaster risk management. Residential areas adjacent to the source of the earthquake is an earthquake-prone area so, therefore it is necessary strategic steps to protect the public and disaster mitigation measures are an attempt to reduce or minimize the impact of loss or damage that may be caused by the disaster. The study was conducted to provide information to the seismic vulnerability using multicriteria analysis of conditions in the region include University of Muhammadiyah Jember dominant period land values   and the value of the amplification factor. The experiment was conducted using subsurface observation with mikrotremoR. From the results of geological studies research area is the basic constituent of igneous rocks such as tuff Argopuro. The results showed that the natural frequency of the soil and soil amplification is at 2,692 and 4,625 Hz. whereas soil vulnerability index value is equal to 7,946.Key Words : seismic, vulnerability, indexAbstrakFenomena alam gempa bumi sampai saat ini belum bisa diprediksi dan waktu yang tepat itu terjadi . Bahaya gempa tidak dapat dihindari namun dampaknya dapat dikurangi melalui kegiatan penilaian gempa bumi karakteristik di daerah yang akan diterapkan dalam pemilihan metode dan kebijakan untuk manajemen risiko bencana . Daerah pemukiman yang berdekatan dengan sumber gempa adalah daerah rawan gempa sehingga , oleh karena itu langkah-langkah strategis yang diperlukan untuk melindungi tindakan publik dan mitigasi bencana merupakan upaya untuk mengurangi atau meminimalkan dampak kerugian atau kerusakan yang mungkin disebabkan oleh bencana. Penelitian ini dilakukan untuk memberikan informasi kepada kerentanan seismik menggunakan analisis multikriteria kondisi di kawasan ini mencakup Universitas Muhammadiyah Jember nilai tanah periode dominan dan nilai faktor amplifikasi . Penelitian dilakukan dengan menggunakan observasi bawah permukaan dengan mikrotremoR. Dari hasil daerah penelitian studi geologi adalah konstituen dasar batuan beku seperti tuf Argopuro . Hasil penelitian menunjukkan bahwa frekuensi alami amplifikasi tanah dan tanah di 2,692 dan 4.625 Hz . sedangkan nilai indeks kerentanan tanah sama dengan 7946 .Kata Kunci : seismik , kerentanan , indeks

scholarly journals Local Site Effects Evaluation Using Microtremor Measurements at North Side of Pandan Mountain

2017 ◽  
Vol 1 (2) ◽  
pp. 89 ◽  
Author(s):  
Samsul Hidayat ◽  
Dwa Desa Warnana ◽  
Sorja Koesuma ◽  
C Cari
Keyword(s):  
Natural Frequency ◽  
Amplification Factor ◽  
Spectral Ratio ◽  
Vulnerability Index ◽  
Disaster Mitigation ◽  
Residential Areas ◽  
Weak Zone ◽  
Local Site ◽  
Index Value ◽  
The Impact

Disaster mitigation has been undertaken to reduce the impact of loss or damage caused by the earthquake. For disaster mitigation purpose, it is necessary to conduct a local geological assessment. The horizontal to vertical spectral ratio (HVSR) of microtremor analysis is very popular in the context of seismic micro-zonation. Microtremor method is cheap, data acquisition is easy, and does not cause noise, so suitable for use in residential areas. This research aims to determine the distribution of the natural frequency value, the amplification factor value, and the soil vulnerability index value. This study was conducted geographically between 7°26'17.45" – 7°26'53.16" S and 111°47'14.76" – 111°48'7.06" E. Data processing using HVSR analysis method on Easy HVSR software. The results showed that the natural frequency (<em>f<sub>o</sub></em>) values range 0,95 Hz to 8,3 Hz and the amplification factor values range 2,05 to 8,67. From the result data of the natural frequency and the amplification factor, the soil vulnerability index can be calculated. The vulnerability index (Kg) value ranges from 1,09 to 68,33. The northeast side of the study area is indicated as a weak zone where have high potential to damage when the earthquake occurred.

scholarly journals Studi Mikrotremor dengan Metode Horizontal to Vertical Spectral Ratio (HVSR) di Tapak RDE, Serpong

EKSPLORIUM ◽  
2019 ◽  
Vol 40 (2) ◽  
pp. 105
Author(s):  
Eko Rudi Iswanto ◽  
Yuni Indrawati ◽  
Theo Alvin Riyanto
Keyword(s):  
Seismic Vulnerability ◽  
Nuclear Reactor ◽  
Amplification Factor ◽  
Power Reactor ◽  
Spectral Ratio ◽  
Vulnerability Index ◽  
Historical Records ◽  
Hvsr Method ◽  
Subsurface Investigation ◽  
Selection For

ABSTRAKBencana alam seperti kejadian gempa bumi dapat menyebabkan kerusakan pada area tapak dan infrastruktur termasuk fasilitas reaktor nuklir. Fenomena ini perlu dipahami secara komprehensif melalui catatan sejarah karakteristik dinamik tapak. Penggunaan mikrotremor dengan metode Horizontal to Vertical Spectral Ratio (HVSR) telah digunakan secara luas dalam investigasi bawah permukaan sejak satu dekade terakhir. Tujuan penelitian ini adalah mengetahui karakteristik geologi setempat dan karakteristik dinamis bawah permukaan. Penelitian ini mengaplikasikan penggunaan mikrotremor metode HVSR di tapak Reaktor Daya Eksperimental (RDE) di Serpong. Pengukuran dilakukan di 15 lokasi, kemudian data diolah dengan metode HVSR menggunakan perangkat lunak Geopsy. Hasil analisis menunjukkan bahwa Tapak RDE mempunyai nilai frekuensi dominan antara 3,06 Hz–23,27 Hz dan faktor amplifikasi 1,84–6,37. Bagian timur laut dan tenggara tapak memiliki indeks kerentanan seismik yang lebih tinggi dibandingkan dengan bagian lainnya. Oleh karena itu, pilihan lokasi gedung reaktor di area barat daya sudah tepat kerena memiliki faktor amplifikasi, ketebalan sedimen, dan indeks kerentanan seismik yang relatif rendah.ABSTRACTNatural disaster like earthquake can cause damage to the site and the infrastructure including nuclear reactor facilities. This phenomenon needs comprehensively understood through its dynamic characteristics historical records of the site. The use of Horizontal to Vertical Spectral Ratio (HVSR) method has been widely used for subsurface investigation since last decade. The aimed of the research is to obtain local geological and subsurface dynamic characetristics. This research is applying the use of HVSR method for Experimental Power Reactor (RDE) in Serpong. The measurements are in 15 locations, and then the data is processed by using Geopsy software. The analysis result shows that the RDE site has dominant frequncy values between 3.06 Hz–23.271 Hz and amplification factor 1.84–6.37. The northeast and southeast areas of the site have higher seismic vulnerability index than in other area. Therefore, the selection for reactor bulding location in the southwest area is proper because it has lower amplification factor, sedimen thickness, and seismic vulnerability index.

Sign in / Sign up

Export Citation Format

Share Document