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Contact Name
Sandri Erfani, S.Si, M.Eng.
Contact Email
sandri.erfani@eng.unila.ac.id
Phone
+6282350155362
Journal Mail Official
jge.tgu@eng.unila.ac.id
Editorial Address
Geophysical Engineering Department Engineering Faculty Universitas Lampung, Prof. Dr. Sumantri Brojonegoro Street No 1, Rajabasa District, Bandar Lampung, Indonesia 35145
Location
Kota bandar lampung,
Lampung
INDONESIA
Jurnal Geofisika Eksplorasi
Published by Universitas Lampung
ISSN : 23561599     EISSN : 26856182     DOI : https://doi.org/10.23960/jge
Core Subject : Science,
Jurnal Geofisika Eksplorasi adalah jurnal yang diterbitkan oleh Jurusan Teknik Geofisika Fakultas Teknik Universitas Lampung. Jurnal ini diperuntukkan sebagai sarana untuk publikasi hasil penelitian, artikel review dari peneliti-peneliti di bidang Geofisika secara luas mulai dari topik-topik teoritik dan fundamental sampai dengan topik-topik terapandi berbagai bidang. Jurnal ini terbit tiga kali dalam setahun (Maret, Juli dan November), Volume pertama terbit pada tahun 2013 dengan nama Jurnal Geofisika Eksplorasi (JGE).
Articles 14 Documents
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ANALISIS PENURUNAN MUKA TANAH DENGAN SMALL BASELINE SUBSET DIFFERENTIAL SAR INTERFEROGRAMS DI KOTA BANDAR LAMPUNG Setyadi, Bagas; Rustadi, Rustadi
JGE (Jurnal Geofisika Eksplorasi) Vol 5, No 2 (2019)
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.1179

Abstract

Abstrak - Bandar Lampung adalah salah satu kota di Indonesia yang berpotensi mengalami penurunan muka tanah karena adanya ekstraksi air tanah, kegiatan pertambangan, alihfungsi lahan, dan kondisi geologi. Untuk itu dilakukan studi penurunan muka tanah dengan teknik SBAS, dikarenakan sangat kurangnya informasi mengenai gejala penurunan muka tanah di Kota Bandar Lampung. Dalam penelitian ini digunakan 15 data SAR dalam selang tahun 2006 ? 2011 yang kemudian dikombinasikan untuk menghasilkan 40 interferogram yang kemudian di-inversi sehingga menghasilkan data deformasi time-series dan kecepatan deformasi rata-rata. Akurasi kecepatan yang diperoleh dengan teknik SBAS sangat bergantung terhadap jenis tutupan lahan di daerah studi, selain itu diketahui pula bahwa penurunan muka tanah di Bandar Lampung rata-rata adalah 0,06 mm/tahun, yang dinilai cukup stabil dikarenakan tatanan geologi yang tidak memungkinkan untuk terjadinya proses konsolidasi secara masif. Beberapa area mengalami indikasi penurunan muka tanah >5 mm/tahun yang diduga disebabkan oleh aktivitas tektonik dan kegiatan manusia (industri, pertambangan, ekstraksi air tanah, dan alihfungsi lahan) yang kemudian berimplikasi terhadap kerusakan struktur bangunan, terjadinya banjir rob di daerah pesisir, dan tanah longsor di daerah perbukitan.  Abstract - Bandar Lampung is one of the cities in Indonesia, which has a potential to land subsidence due to the extraction of ground water, mining, land conversion, and geological conditions. For that reason, carried out the study of land subsidence with SBAS technique, due to the very lack of information about the symptoms of land subsidence in Bandar Lampung. In this study, 15 SAR data in 2006 to 2011 used and then combined to produce 40 interferogram then inverted resulting in a time-series deformation and deformation speed average. Velocity precision obtained with SBAS technique is highly dependent on the type of land cover in the study area, but it is known that the average of land subsidence in Bandar Lampung is about 0.06 mm/year, which is considered quite stable due to the geological structure that does not allow for the occurrence of massive consolidation process. Several areas have indications of subsidence> 5 mm/year are suspected to be caused by tectonic activity and human activity (industrial, mining, extraction of groundwater, and land conversion), which then has implications for structural damage to buildings, flooding in coastal areas, and landslides in hilly areas.
INTERPRETASI SISTEM PANAS BUMI SUWAWA BERDASARKAN DATA GAYA BERAT Rizkiani, Dian Nur; Rustadi, Rustadi
JGE (Jurnal Geofisika Eksplorasi) Vol 5, No 2 (2019)
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.1180

Abstract

Abstrak - Penelitian gaya berat pada panas bumi daerah Kecamatan Suwawa dilakukan dengan tujuan untuk menentukan struktur sesar dengan menggunakan teknik Second Vertical Derivative (SVD), membuat model bawah permukaan 2D dan model tentatif 3D menggunakan data anomali regional dan menginterpretasi sistem panas bumi Suwawa. Pengolahan data yang dilakukan dalam penelitian meliputi : koreksi apungan, koreksi medan, anomali udara bebas, anomali Bouguer lengkap, analisis spektral, analisis SVD, pemodelan 2D dan pemodelan inversi 3D serta model tentatif untuk menginterpretasi sistem panas bumi Suwawa. Hasil penelitian menunjukkan bahwa  daerah penelitian memiliki  anomali Bouguer rendah dengan rentang nilai 75.8 hingga 79.5 mGal berada pada bagian Barat dan Tenggara, sedangkan anomali tinggi dengan rentang nilai 90.9 hingga 111.2 mGal berada pada bagian Utara dan Selatan, adanya korelasi sesar berdasarkan analisa SVD dengan sesar geologi yang menunjukkan keberadaan mata air panas Libungo, hasil inversi menunjukkan adanya densitas rendah (? = 1,8 gr/cc) yang merupakan batuan aluvial dan densitas tinggi (? = 2,9 gr/cc) yang merupakan batuan Lava Andesit Dasitan, pemodelan tentatif 3D menunjukkan keberadaan  reservoir berada pada kedalaman 2 km dari permukaan tanah. Berdasarkan model yang dibuat, Cap Rock berada pada batuan Lava Andesit Dasitan dengan ? = 2,9 gr/cc pada kedalaman 1200 m dan Heat Source berada pada kedalaman > 2000 m.  Abstract - The research of gravity on Suwawa Sub-District geothermal is done for the purposes to determine fault structure using Second Vertical Derivative (SVD) technique, create a 2D subsurface model and 3D tentative model using regional anomaly data, and interpreting Suwawa geothermal system. Data processing is done in the research include: drift correction, terrain correction, free air correction, complete Bouguer anomaly, spectral analysis, SVD analysis, 2D modeling and 3D inversion modeling and tentative model. The research results showed that the research area has low Bouguer anomaly with a range of 75.8 to 79.5 mGal values in the West and Southeast, while high anomaly with a range of 90.9 to 111.2 mGal values in the Northern and Southern, there is correlation of fault based on SVD analysis with geological fault that indicate the presence of Libungo hot springs, the inversion results indicate the presence of low density (? = 1.8 g/cc) which is an alluvial rocks and high density (? = 2.9 g/cc) which is Andesite Lava rocks, 3D tentative modeling indicate the presence of reservoir is at a depth of 2 km from the ground surface. Based on the model created, Cap Rock is located on Andesite Lava rocks with ? = 2.9 g/cc at a depth of 1200 m and Heat Source located at a depth of > 2000 m.
ANALISA LUASAN TERUMBU KARANG DI PERAIRAN PULAU TEGAL LAMPUNG DENGAN TEKNOLOGI PENGINDERAAN JAUH Muhtar, Faris; Armijon, Armijon; Murdapa, Fauzan; Fadly, Romi
JGE (Jurnal Geofisika Eksplorasi) Vol 5, No 2 (2019)
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.1181

Abstract

Abtrak - Kerusakan terumbu karang di Pulau Tegal berdampak terhadap berkurangnya habitat terumbu karang, sehingga perlu dilakukan monitoring. Monitoring dilakukan dengan analisis luasan dan perubahannya dengan memanfaatkan teknologi penginderaan jauh untuk pemetaan kondisi eksistingnya. Data yang digunakan yaitu citra landsat pada tahun 1998, 2008, 2015 dan 2018. Pengolahan citra digital dilakukan mulai dari koreksi citra, perhitungan algoritma lyzenga, interpretasi citra dan validasi lapangan, serta dilakukan uji akurasi habitat terumbu karang menggunakan matriks konfusi. Hasil penelitian menunjukan bahwa terjadi perubahan luasan terumbu karang dari tahun 1998 ? 2018. Kelas terumbu karang mengalami pengurangan seluas 11,22 ha. Kelas terumbu karang yang berubah menjadi kelas pasir seluas 9,13 ha (29,49%) dan lamun seluas 4,38 ha (14,15%). Kelas pasir yang berubah menjadi terumbu karang seluas 2,08 ha (13,52%) dan kelas lamun yang berubah menjadi terumbu karang seluas 0,21 ha (0,25%). Perubahan yang paling besar yaitu perubahan terumbu karang menjadi pasir seluas 9,13 ha (29,49%), sedangkan perubahan paling kecil yaitu perubahan lamun menjadi terumbu karang seluas 0,21 ha (0,25%). Pada kelas lainnya perubahan luasan paling besar yaitu perubahan lamun menjadi pasir seluas 5,76 ha (6,96%), sedangkan perubahan paling kecil yaitu perubahan pasir menjadi lamun seluas 2,67 ha (17,35%).  Abstract - Damage to coral reefs on Tegal Island has an impact on reducing coral reef habitats, so monitoring needs to be done. Monitoring is done by analyzing the extent and changes by utilizing remote sensing technology to map the existing conditions. The data used are Landsat imagery in 1998, 2008, 2015 and 2018. Digital image processing is done starting from image correction, lyzenga algorithm calculation, image interpretation and field validation, and accuracy testing of coral reef habitats using a confusion matrix. The results showed that there was a change in the area of coral reefs from 1998 to 2018. The coral reef class experienced a reduction of 11.22 ha. Coral classes that changed into sand classes were 9.13 ha (29.49%) and seagrasses were 4.38 ha (14.15%). The class of sand that turned into coral reefs was 2.08 ha (13.52%) and seagrass classes that turned into coral reefs were 0.21 ha (0.25%). The biggest change is the change in the coral reef to sand covering an area of 9.13 ha (29.49%), while the smallest change is the change in seagrass into a coral reef covering an area of 0.21 ha (0.25%). In the other classes, the biggest change in area was seagrass change into sand covering an area of 5.76 ha (6.96%), while the smallest change was the change in the sand to seagrass covering an area of 2.67 ha (17.35%).
PEMODELAN 3D STRUKTUR BAWAH PERMUKAAN GUNUNGAPI AGUNG PROVINSI BALI MENGGUNAKAN METODE GAYA BERAT Ilmi, Nasyratul; Karyanto, Karyanto
JGE (Jurnal Geofisika Eksplorasi) Vol 5, No 2 (2019)
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.1182

Abstract

Abstrak - Telah dilakukan penelitian dengan tema ?Pemodelan 3D Struktur Bawah Permukaan Gunungapi Agung Provinsi Bali Menggunakan Metode Gaya Berat?. Penelitian ini bertujuan untuk mengidentifikasi kantong magma dan membuat model bawah permukaan Gunungapi Agung Provinsi Bali menggunakan data anomali gaya berat. Metode pengolahan data yang dilakukan dalam penelitian ini ialah (i) membuat peta kontur Anomali Bouguer, (ii) melakukan analisis spektrum (iii) melakukan pemisahan anomali regional dan residual (iv) melakukan analisis Second Vertical Derivative, (v) membuat penampang geologi bawah permukaan secara 3D (inverse modelling) (vi) melakukan interpretasi kualitatif dan kuantitatif. Hasil pada peta Anomali Bouguer menunjukkan nilai anomali Bouguer daerah penelitian berkisar antara 84 mGal yang tersebar pada bagian barat daya daerah penelitian sampai 279 mGal yang berada pada tubuh Gunungapi Agung. Batas antara batuan dasar dan batuan sedimen daerah penelitian terdapat pada kedalaman 0,89 km. Kantong magma Gunungapi Agung berada pada kedalaman 500 hingga 8000 meter dengan bentuk menjulang ke atas dan cembung dibagian tengahnya. Kantong magma ini memiliki densitas sebesar 2,73 ? 2,86 gr/cc. Jika dilihat dari model yang didapat aliran magma di dalam Gunungapi Agung terlihat pada kedalaman 0 meter. Abstract - Under surface structure, 3d modelling of Agung volcano in Bali had been conducted by using gravity methods. This research aims to identify the magma chamber and make a model below the surface of the Great Volcano of Bali Province by using gravity anomaly data. Data processing methods performed in this research were consists of six steps: (i) arrangement the contour map of Bouguer anomaly, (ii) spectrum analysis, (iii) anomaly regional and residual separation, (iv) Second Vertical Derivative analysis, (v) cross-section of subsurface geology construction by using 3D (inverse modelling), (vi) qualitative and quantitative interpretation. Anomaly Bougeur contour map result shows the value of Bouguer anomaly in research area around 84 mGal spreading around west-south part of research point until 279 mGal on Agung volcano body. Anomaly regional value is around 97 mGal to 253 mGal. The boundary between basement a sedimentary rock of the research area are at the depth of 0,89 km. The magma chamber of Agung volcano is in the depth of 500 to 8000 metres to a form of towing up and polluted in the middle. The density of the magma chamber is around 2,73 until 2,86 gr/cc. The magma flow in the Agung volcano of visible at the depth of 0 metres.
INVERSI MIKROTREMOR UNTUK PROFILING KECEPATAN GELOMBANG GESER (Vs) DAN MIKOROZONASI KABUPATEN BANDUNG Zuhaera, Andina; Suharno, Suharno
JGE (Jurnal Geofisika Eksplorasi) Vol 5, No 2 (2019)
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.1177

Abstract

Abstrak - Kabupaten Bandung merupakan daerah dataran tinggi dengan kemiringan antara 0 ? 8%, 8 ? 15% hingga di atas 45%. Kabupaten ini terletak pada ketinggian 768 m di atas permukaan laut dengan daerah utara lebih tinggi dibandingkan daerah sebelah selatan. Tujuan dilakukannya penelitian ini adalah mengetahui sebaran gelombang Vs30 dan mengetahui dampak kerusakan akibat adanya penguatan gelombang (amplifikasi). Untuk memperkecil dampak dari gempabumi ini identifikasi yang dapat dilakukan diantaranya survei untuk memetakan karakteristik tanah dalam merespon guncangan gempabumi menggunakan metode seismik Horizontal to Vertical Spectral Ratio (HVSR). Berdasarkan hasil penelitian persebaran nilai frekuensi dominan, Kabupaten Bandung teridentifikasi memiliki tanah yang keras dan batuan lunak serta memiliki clay padat dengan ketebalan puluhan meter. Nilai amplifikasi di Kabupaten Bandung memiliki nilai (0 < Ao < 6) yang dapat dikategorikan bahwa Kabupaten Bandung memiliki dampak kerusakan yang kecil terhadap gempabumi. Perbedaan antara hasil pengolahan inversi dan HVSR disebabkan asumsi bahwa pada inversi lapisan bersifat heterogen dan pada HVSR lapisan bersifat homogen.  Abstract - Bandung Regency is a highland area with a slope between 0 - 8%, 8-15% to above 45%. The district is located at an altitude of 768 m above sea level with the northern region higher than the south. The purpose of this study was to determine the distribution of Vs30 waves and determine the impact of damage due to wave amplification (amplification). To minimize the impact of this earthquake identification can be done including a survey to map soil characteristics in response to earthquake shocks using the seismic Horizontal to Vertical Spectral Ratio (HVSR) method. Based on the results of the study, the distribution of the dominant frequency values, Bandung Regency was identified as having hard and soft rock soil and having solid clay with a thickness of tens of meters. The amplification value in Bandung Regency has a value (0 <Ao <6) which can be categorized that Bandung Regency has a small impact on the earthquake. The difference between the results of inversion processing and HVSR is due to the assumption that the layer inversion is heterogeneous and the HVSR layer is homogeneous.
ANALISIS ZONA BAHAYA GEMPABUMI BERDASARKAN METODE DETERMINISTIK DAN PENDEKATAN GEOMORFOLOGI KOTA PADANG SUMATERA BARAT Riyanti, Azis; Rasimeng, Syamsurijal
JGE (Jurnal Geofisika Eksplorasi) Vol 5, No 2 (2019)
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.1178

Abstract

Abstrak - Telah dilakukan penelitian tentang analisis bahaya gempabumi berdasarkan metode deterministik dan pendekatan geomorfologi Kota Padang dengan tujuan untuk mengetahui nilai percepatan tanah maksimum (PGA) dan amplifikasi dari sumber gempa patahan Suliti dan Sumber gempa Subduksi serta menentukan kelas tanah berdasarkan gelombang geser (Vs30). Untuk mendapatkan nilai PGA, terdapat beberapa persamaan atenuasi yang digunakan untuk mencari besarnya guncangan yang dihasilkan apabila terjadi gempa dangkal. Untuk sumber gempa patahan, persamaan atenuasi yang digunakan adalah persamaaan Boore-Atkinson, Campbell-Bozorgnia, dan Chiou-Young. Sedangkan persamaan atenuasi yang digunakan untuk mendapatkan nilai PGA dari sumber gempa subduksi adalah Atkinson-Boore, Youngs, serta Zhao. Nilai PGA sumber gempa Subduksi di batuan dasar 0,0374 g. Sementara nilai PGA di permukaan sebesar 0,0769 g. Sedangkan untuk nilai PGA pada sumber gempa patahan (Patahan Suliti) di batuan dasar berkisar antara 0,0376 g, sementara nilai PGA di permukaan berkisar 0,0573 g. Daerah yang memiliki dampak parah jika terjadi gempa yang bersumber dari patahan adalah Kecamatan Koto Tengah, Kcamatan Padang Barat, dan Kecamatan Padang Utara dengan nilai amplifikasi tertinggi yakni 1,7690 (> 9 kali) yang menunjukkan bahwa perbesaran gelombang didaerah tersebut tinggi. Sedangkan jika terjadi gempa dengan sumber gempa subduksi daerah yang sangan rawan adalah Kecamatan Padang Barat, Kecamatan Koto Tengah, Kecamatan Padang Utara dengan nilai amplifikasi 2,0607 (> 9 kali).  Abstract - Research on earthquake hazard analysis based on deterministic methods and the geomorphology approach of Padang City has been carried out to determine the maximum soil acceleration (PGA) and amplification of the source of the Suliti faults and Earthquake Subduction and determine soil classes based on shear waves (Vs30). The PGA value, several attenuation equations are used to find the magnitude of the shock produced when a shallow earthquake occurs. For the source of fault earthquakes, the attenuation equations used are the equivalent of Boore-Atkinson, Campbell-Bozorgnia, and Chiou-Young. While the attenuation equations used to obtain PGA values from subduction earthquake sources are Atkinson-Boore, Youngs, and Zhao. PGA value of earthquake source Subduction in bedrock 0.0374 g. While the PGA value on the surface is 0.0769 g. Whereas the PGA value in the fault source (Hard Fault) in bedrock ranged from 0.0376 g, while the PGA value on the surface ranged from 0.0573 g. Areas that have a severe impact if an earthquake originates from a fault are Koto Tengah District, West Padang Subdistrict, and North Padang Subdistrict with the highest amplification value of 1.7690 (> 9 times) which indicates that the magnification of the area is high. Whereas in the case of an earthquake with an earthquake source subduction area which is very vulnerable is West Padang District, Koto Tengah District, Padang Utara District with an amplification value of 2.0607 (> 9 times).
INVERSI MIKROTREMOR UNTUK PROFILING KECEPATAN GELOMBANG GESER (VS) DAN MIKOROZONASI KABUPATEN BANDUNG Zuhaera, Andina; Suharno, Suharno; Mulyatno, Bagus Sapto
Jurnal Geofisika Eksplorasi Vol 5, No 2 (2019)
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.25

Abstract

Bandung Regency is a highland area with a slope between 0 - 8%, 8-15% to above 45%. The district is located at an altitude of 768 m above sea level with the northern region higher than the south. The purpose of this study was to determine the distribution of Vs30 waves and determine the impact of damage due to wave amplification (amplification). To minimize the impact of this earthquake identification can be done including a survey to map soil characteristics in response to earthquake shocks using the seismic Horizontal to Vertical Spectral Ratio (HVSR) method. Based on the results of the study, the distribution of the dominant frequency values, Bandung Regency was identified as having hard and soft rock soil and having solid clay with a thickness of tens of meters. The amplification value in Bandung Regency has a value (0 Ao 6) which can be categorized that Bandung Regency has a small impact on the earthquake. The difference between the results of inversion processing and HVSR is due to the assumption that the layer inversion is heterogeneous and the HVSR layer is homogeneous.
ANALISIS ZONA BAHAYA GEMPABUMI BERDASARKAN METODE DETERMINISTIK DAN PENDEKATAN GEOMORFOLOGI KOTA PADANG SUMATERA BARAT Riyanti, Azis; Rasimeng, Syamsurijal
Jurnal Geofisika Eksplorasi Vol 5, No 2 (2019)
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.26

Abstract

Research on earthquake hazard analysis based on deterministic methods and the geomorphology approach of Padang City has been carried out to determine the maximum soil acceleration (PGA) and amplification of the source of the Suliti faults and Earthquake Subduction and determine soil classes based on shear waves (Vs30). The PGA value, several attenuation equations are used to find the magnitude of the shock produced when a shallow earthquake occurs. For the source of fault earthquakes, the attenuation equations used are the equivalent of Boore-Atkinson, Campbell-Bozorgnia, and Chiou-Young. While the attenuation equations used to obtain PGA values from subduction earthquake sources are Atkinson-Boore, Youngs, and Zhao. PGA value of earthquake source Subduction in bedrock 0.0374 g. While the PGA value on the surface is 0.0769 g. Whereas the PGA value in the fault source (Hard Fault) in bedrock ranged from 0.0376 g, while the PGA value on the surface ranged from 0.0573 g. Areas that have a severe impact if an earthquake originates from a fault are Koto Tengah District, West Padang Subdistrict, and North Padang Subdistrict with the highest amplification value of 1.7690 ( 9 times) which indicates that the magnification of the area is high. Whereas in the case of an earthquake with an earthquake source subduction area which is very vulnerable is West Padang District, Koto Tengah District, Padang Utara District with an amplification value of 2.0607 ( 9 times).
ANALISIS PENURUNAN MUKA TANAH DENGAN SMALL BASELINE SUBSET DIFFERENTIAL SAR INTERFEROGRAMS DI KOTA BANDAR LAMPUNG Setyadi, Bagas; Rustadi, Rustadi
Jurnal Geofisika Eksplorasi Vol 5, No 2 (2019)
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.27

Abstract

Bandar Lampung is one of the cities in Indonesia, which has a potential to land subsidence due to the extraction of ground water, mining, land conversion, and geological conditions. For that reason, carried out the study of land subsidence with SBAS technique, due to the very lack of information about the symptoms of land subsidence in Bandar Lampung. In this study, 15 SAR data in 2006 to 2011 used and then combined to produce 40 interferogram then inverted resulting in a time-series deformation and deformation speed average. Velocity precision obtained with SBAS technique is highly dependent on the type of land cover in the study area, but it is known that the average of land subsidence in Bandar Lampung is about 0.06 mm/year, which is considered quite stable due to the geological structure that does not allow for the occurrence of massive consolidation process. Several areas have indications of subsidence 5 mm/year are suspected to be caused by tectonic activity and human activity (industrial, mining, extraction of groundwater, and land conversion), which then has implications for structural damage to buildings, flooding in coastal areas, and landslides in hilly areas.
PEMODELAN 3D STRUKTUR BAWAH PERMUKAAN GUNUNGAPI AGUNG PROVINSI BALI MENGGUNAKAN METODE GAYA BERAT Ilmi, Nasyratul; Karyanto, Karyanto
Jurnal Geofisika Eksplorasi Vol 5, No 2 (2019)
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.30

Abstract

Under surface structure, 3d modelling of Agung volcano in Bali had been conducted by using gravity methods. This research aims to identify the magma chamber and make a model below the surface of the Great Volcano of Bali Province by using gravity anomaly data. Data processing methods performed in this research were consists of six steps: (i) arrangement the contour map of Bouguer anomaly, (ii) spectrum analysis, (iii) anomaly regional and residual separation, (iv) Second Vertical Derivative analysis, (v) cross-section of subsurface geology construction by using 3D (inverse modelling), (vi) qualitative and quantitative interpretation. Anomaly Bougeur contour map result shows the value of Bouguer anomaly in research area around 84 mGal spreading around west-south part of research point until 279 mGal on Agung volcano body. Anomaly regional value is around 97 mGal to 253 mGal. The boundary between basement a sedimentary rock of the research area are at the depth of 0,89 km. The magma chamber of Agung volcano is in the depth of 500 to 8000 metres to a form of towing up and polluted in the middle. The density of the magma chamber is around 2,73 until 2,86 gr/cc. The magma flow in the Agung volcano of visible at the depth of 0 metres.

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