scholarly journals Subsurface Structure Models Of Sumbawa Island And Flores Back Arc Thrust Based On Gravity Data

2021 ◽  
Vol 7 (3) ◽  
pp. 414
Author(s):  
Suhayat Minardi ◽  
Ahmad Mudyanto ◽  
Hiden Hiden
Keyword(s):  
Cross Section ◽  
3D Model ◽  
Gravity Data ◽  
Secondary Data ◽  
Reverse Fault ◽  
Subsurface Structure ◽  
Eurasian Plate ◽  
Vertical Derivative ◽  
Thrust Zone ◽  
Back Arc

Based on the BMKG report on Wednesday, July 29, 2018, at 05.47 WIB, an earthquake with a magnitude of 6.4 SR occurred at the epicenter at a depth of 24 km and was 47 km northeast of the island of Lombok. They are allegedly originating from the Back Arc Thrust Flores, the interaction between the Indo-Australian Plate and the Eurasian plate. This study aims to analyze the subsurface structure of the island of Sumbawa and Flores sea based on the distribution of density values. The analysis was carried out by modeling the subsurface structure based on regional gravity field anomaly data. The data used is secondary data downloaded from the topex.ucsd.edu page 18,400 measuring points. Data processing consists of data correction, separation of anomalies, determination of the Second Vertical Derivative (SVD) value, and 3D and 2D inversion modeling. The data corrections performed are Bouguer correction and terrain correction to produce the total gravity anomaly value. Upward continuation is used to separate regional anomalies and residual anomalies. Analysis of the Second Vertical Derivative (SVD) value was carried out to identify rock contact positions and fault structures. The 3D inversion modeling is done by making a mesh model, and to get a 2D cross-section, six slices are used in the 3D model. The results of the 3D model and 2D cross-section, namely the island of Sumbawa to the Back Arc Thrust zone of Flores, consists of 3 main layers comprised of the upper crust with a density of 2.29 gr/cc - 2.63 gr/cc, the middle crust with a density of 2.64 gr/cc - 2.90 gr/cc, and the lower crust with a density of 2.91 gr/cc - 3.14 gr/cc, and based on the model and SVD value, it shows that the Flores back fault, the reverse fault type, starts at a depth of ± 26 km

scholarly journals Coastal vulnerability mapping due to tsunami using Geographic Information System in Buleleng Regency, Bali Province

2021 ◽  
Vol 944 (1) ◽  
pp. 012045
Author(s):  
N P A R Suhita ◽  
V P Siregar ◽  
J Lumban-Gaol
Keyword(s):  
Information System ◽  
Geographic Information System ◽  
Field Data ◽  
Secondary Data ◽  
Geographic Information ◽  
Coastal Vulnerability ◽  
Earthquake Sources ◽  
Thrust Zone ◽  
Geographical Position ◽  
Back Arc

Abstract Bali is one of the areas vulnerable to disasters because of its geographical position, which is flanked by two earthquake sources in the form of a subduction zone and back-arc thrust zone, which can cause a tsunami in Bali region. This research aims to identify and map the level of coastal vulnerability to the tsunami in Buleleng Regency, Bali Province. The mapping was carried out using Geographic Information System (GIS). This study used secondary data and field data. The parameters used in analyzing the level of tsunami vulnerability were land elevation, slope, landuse, distance from the beach, and distance from the river. The level of vulnerability was grouped into five classes, namely very safe (35,466.9 ha), safe (70,485.0 ha), moderately vulnerable (17,645.0 ha), vulnerable (6,903.3 ha), and very vulnerable (438.9 ha) located in the Districts of Gerokgak, Seririt, Buleleng, and Sawan which are close to the river.

scholarly journals Studi Identifikasi Struktur Geologi Bawah Permukaan Untuk Mengetahui Sistem Sesar Berdasarkan Analisis First Horizontal Derivative (FHD), Second Vertical Derivative (SVD), Dan 2,5D Forward Modeling Di Daerah Manokwari Papua Barat

2020 ◽  
Vol 4 (2) ◽  
pp. 62-76
Author(s):  
Shiska Yulistina
Keyword(s):  
Cross Section ◽  
Gravity Data ◽  
Bouguer Anomaly ◽  
Forward Modeling ◽  
Research Area ◽  
Geological Structure ◽  
North West ◽  
Vertical Derivative ◽  
Horizontal Derivative ◽  
Papua Barat

In general, Manokwari has a geological structure that is in the form of a folding area found in the highlands of the mountains. Among the creases, there is a fault up and the fault down. In coastal or marine areas found many reefs and corals. The study of gravity was conducted in the Manokwari area of West Papua with the aim to know the subsurface geological structures based on FHD (First Horizontal Derivative), SVD (Second Vertical Derivative) and 2.5D Forward Modeling on the residual anomaly maps of the study area. The results showed that the research area has Bouguer Anomaly value ranged from 4 mGal to 96 mGal with the low anomaly at the left side of the research area lengthwise relatively in north-west to south-east direction, the middle-value anomaly spreads in the west-east area of research area, high anomaly scattered in the northern part of the research area. The results of the 2.5D subsurface modeling and the SVD and FHD analysis indicated the presence of a Thrust Fault on the C-C’ cross-section, on the B-B’ cross-section there is a Diorite Lembai intrusion with the density value is 2.75 gr/cc, whereas the A-A' cross-section which intersects with Sorong fault were not found any fault or rock intrusion based on observed gravity data of the research area.

scholarly journals Reservoir Identification Based on Gravity Method at “AUN” Geothermal Field

2019 ◽  
Vol 125 ◽  
pp. 14008
Author(s):  
Annisa Dwi Hafidah ◽  
Yunus Daud ◽  
Alfian Usman
Keyword(s):  
Gravity Data ◽  
Geothermal Field ◽  
Gravity Inversion ◽  
Eurasian Plate ◽  
Gravity Method ◽  
Vertical Derivative ◽  
Horizontal Derivative ◽  
Sumatra Island ◽  
Result Show ◽  
Subsurface Layers

Sumatra Island has the largest geothermal potential in Indonesia spread along the subduction zone between the Indian-Australian plate and the Eurasian plate. “AUN” geothermal field located in Sumatra Island and considered to be one of the largest potential geothermal prospects in Indonesia. This study is focused on identifying the prospect of “AUN” geothermal field using gravity method. First Horizontal Derivative (FHD) and Second Vertical Derivative (SVD) analysis were applied in order to determine a more accurate boundary of the fault. 3D inversions of gravity data were used to reconstruct subsurface model. The result show that analysis of First Horizontal Derivative (FHD) and Second Vertical Derivative (SVD) can confirm southwest-northeast fault and caldera structure as a boundary of geothermal reservoir and 3D gravity inversion can show subsurface layers with density 2.5 gr/cc to 2.8 gr/cc inside the boundary which is determined as a heat source in “AUN” geothermal field.

scholarly journals Gravity anomaly to identify Walanae fault using second vertical derivative method

2018 ◽  
Vol 2 (1) ◽  
pp. 34
Author(s):  
Marsellei Justia ◽  
Muhammad Fikri H Hiola ◽  
Nur Baiti Febryana S
Keyword(s):  
Gravity Data ◽  
Moving Average ◽  
Normal Fault ◽  
Reverse Fault ◽  
The South ◽  
Vertical Derivative ◽  
The North ◽  
Free Air ◽  
Free Air Anomaly ◽  
Fault Mechanism

<p class="Abstract">Research has been conducted to identify the Walanae Fault, coordinates 4–6 S and 118-120 E using anomalous gravity data. This research uses data measurement of Topography and the Free Air Anomaly from the TOPEX/Poseidon satellite. Then the authors processed to obtain the bouguer anomalies and made modeling by using the Surfer 10. The authors used the Second Vertical Derivative (SVD) with filter Elkins of Moving Average then analyze the graph of the SVD. The results shows the value of the residual anomaly in the north of fault is 25.21 mGal, in the middle occur range 17.67 mGal to 24.98 mGal and 30,376 mGal in the south of fault. The authors indicates the existence of a difference between the gravity between the Walanae Fault with surrounding geologic. From these results also show that Walanae Fault has a reverse fault mechanism in the northern part and the normal fault mechanism in the middle to the south, the authors conclude that the Walanae Fault is divided into two segments, that is the northern and the southern segment.</p>

scholarly journals IDENTIFIKASI BAWAH PERMUKAAN LAPANGAN MINYAK“HUF” SUMATERA SELATAN UNTUK MENDELINIASI STRUKTUR CEKUNGAN HIDROKARBON BERDASARKAN DATA GAYABERAT

2020 ◽  
Vol 4 (1) ◽  
pp. 19-32
Author(s):  
Ade Setiawan ◽  
Bagus Sapto Mulyatno
Keyword(s):  
3D Modeling ◽  
3D Model ◽  
Gravity Data ◽  
Bouguer Anomaly ◽  
Hollow Structure ◽  
Field Research ◽  
Oil Field ◽  
Fault Structure ◽  
Vertical Derivative ◽  
A Value

Oil field research in regional Banyuasin “HUF” , South Sumatra have been done by the gravity data with objective of knowing fault structure based on analysis of hydrocarbon SVD and knows hollow structure  based on the 3D model of the Bouguer Anomaly and Residual Anomaly. Study areas had Bouguer Anomaly between 13 mgal up to 33 mgal to the interval 1 mgal, where the value of Bouguer Anomaly high have a range value 26 mgal up to 33 mgal which is in the direction of west. While the low value of Bouguer Anomaly have a range value 13 mgal to 20 mgal that is in the east. To knew the existence of structure fault, filtering Second Vertical Derivative (SVD) on a Bouguer Anomaly, Regional and Residua mapl.Pattern of structure fault indicated the contours of a zero value and between the high and low contours. From the results of the analysis SVD Complete Bouguer Anomaly and SVD Residual Anomaly there were 4 (four) fault, while from SVD Regional Anomaly there are 3 (three) fault. 3D modeling the Residual Anomaly were conducted to prove the existence of the fault SVD analyzed based on the results of the analysis and to know the hydrocarbon basin. Based on the results of the inversion of 3D the Residual Anomaly, basin was found in the depth of 1500 m – 3000 m with a value of the density ranges from 2.24 gram/cc until 2.32 gram/cc which identified as sandstone basin.

scholarly journals 3D Geological Model of the Touro Cu Deposit, A World-Class Mafic-Siliciclastic VMS Deposit in the NW of the Iberian Peninsula

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 85
Author(s):  
Mónica Arias ◽  
Pablo Nuñez ◽  
Daniel Arias ◽  
Pablo Gumiel ◽  
Cesar Castañón ◽  
...  
Keyword(s):  
3D Model ◽  
Massive Sulfide ◽  
Geological Model ◽  
Drill Core ◽  
World Class ◽  
Hinge Zone ◽  
Arc Setting ◽  
Using Data ◽  
Back Arc ◽  
Host Rocks

The Touro volcanogenic massive sulfide (VMS) deposit is located in the NW of the Iberian Variscan massif in the Galicia-Trás-os-Montes Zone, an amalgamation of several allochthonous terrains. The Órdenes complex is the most extensive of the allochthone complexes, and amphibolites and paragneisses host the deposit, characterized as being massive or semimassive (stringers) sulfides, mostly made up of pyrrhotite and chalcopyrite. The total resources are 103 Mt, containing 0.41% copper. A 3D model of the different orebodies and host rocks was generated using data from 1090 drill core logs. The model revealed that the structure of the area is a N–S-trending antiform. The orebodies crop out in the limbs and in the hinge zone. The mineralized structures are mostly tabular, up to 100 m in thickness and subhorizontal. Based on the petrography, geochemistry and the 3D model, the Touro deposit is classified as a VMS of the mafic-siliciclastic type formed in an Ordovician back-arc setting, which was buried and metamorphosed in Middle Devonian.

ANALISIS MODEL 3D DATA GAYA BERAT DALAM KEGAGALAN PEMBORAN SUMUR RESERVOAR MINYAK DI AREA X

2020 ◽  
Vol 2 (2) ◽  
pp. 62-68
Author(s):  
Ahmad Jahrudin ◽  
Pradityo Riyadi
Keyword(s):  
3D Modeling ◽  
3D Model ◽  
Oil And Gas ◽  
Gravity Data ◽  
Production Well ◽  
Log Data ◽  
3D Data ◽  
Area X

The exploration of oil and gas, especially in Indonesia is experiencing various challenges and varying degrees of difficulty. In this research, the researcher tries to make a 3D modeling from gravity data, where the model will show a structure to determine the central coordinates for drilling. Pertamina has carried out drilling at a location in NTT and it turns out that the well does not produce oil and gas, even though the log data reads an oil showing that the area should have the prospect of producing oil, but the wells that have been drilled do not show any oil or gas, therefore the researchers tried to make a 3D model determine the structure around the production well. In this research, it was seen that the area of the previous drilling point had deviated from the top of the up dome and it was also seen in this structure that the area was deviated by about 3 kilometers and depth must exceed 526 m, the researcher concluded that the drilling point must be at X, Y coordinates.

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