Claim Missing Document
Check
Articles

Found 9 Documents
Search

Investigasi Geologi dan Geolistrik Untuk Menafsirkan Keberadaan Air Tanah Dangkal Di Ambarawa, Lampung Rustadi Rustadi; Gurum Ahmad Pauzi; Opik Taufik
Jurnal Teori dan Aplikasi Fisika Vol 6, No 1 (2018): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v6i1.1832

Abstract

East  Ambarawa  has  a  large  agricultural  land  prosfek  for  rice  cultivation.  Limitations  of irrigation facilities, caused land fields are only productive in the rainy season. Utilization of ground water to be an alternative to supporting water supply. For this purpose, a geoelectric survey has  been conducted to   map   the   presence   of   shallow   groundwater   in   three lines   with   random  positions  using  Pole-pole configurations.  Through  the  use  of  40  electrodes  with  a  total   length  of  200  m,  geoelectric image  is obtained  to  a  depth  of  70  m.  The  presence  of  ground  water  is interpreted  to  be  in sedimentary layers, at depths  of  12   -  50.  Underlying  sediment  layers  are  composed  of   igneous  rocks  that  correlate with the formed Kerawang hill.
PEMODELAN DAN ANALISA STRUKTUR BAWAH PERMUKAAN DAERAH PROSPEK PANASBUMI KEPAHIANG BERDASARKAN METODE GAYABERAT Roy Bryanson Sihombing; Rustadi Rustadi
Jurnal Geofisika Eksplorasi Vol 4, No 2 (2018)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v4i2.14

Abstract

Research has been conducted in Kepahiang area using gravity data with the aim of identify faults based on analysis of the Second Vertical Derivative (SVD) and interpreting structure sub-surface of the based on 3D inverse modelling from Bouguer anomaly and residual anomaly. The research area have an Bouguer anomaly between 38 mGal - 74 mGal, where the high Bouguer anomaly value has a value range of 63,2 mGal - 74 mGal located in the southwest direction of the research area. Whereas the low Bouguer anomaly value has a range of values 38 mGal - 47 mGal located in the north of the research area. To know the existence of fault structure in research area, conducted filtering Second Vertical Derivative (SVD) on the map Bouguer anomaly, regional and residual. The structure faulting is shown with contour of zero and between the contours of high and low. From the analysis of SVD complete anomaly Bouguer and SVD residual anomaly there are 8 (eight) faulting, while from SVD regional anomaly there are 4 (four) fault. 3D inversion modeling of the residual anomaly was done to prove the existence of the fault analyzed based on filtering Second Vertical Derivative (SVD). Based on the results of inversion 3D residual anomaly been gained one (1) reservoir in a northern direction research area and two (2) in the direction of west the research area by a contrast the density of -0,0719356 gr/cc until -0,236053 gr/cc with a depth of 0 meters up to 4.705 meters.
INTERPRETASI SISTEM PANAS BUMI SUWAWA BERDASARKAN DATA GAYA BERAT Dian Nur Rizkiani; Rustadi Rustadi
Jurnal Geofisika Eksplorasi Vol 5, No 2 (2019)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.28

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 (ρ = 1.8 g/cc) which is an alluvial rocks and high density (ρ = 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 ρ = 2.9 g/cc at a depth of 1200 m and Heat Source located at a depth of 2000 m.
PENDUGAAN PATAHAN DAERAH “Y” BERDASARKAN ANOMALI GAYABERAT DENGAN ANALISIS DERIVATIVE Yasrifa Fitri Aufia; Karyanto Karyanto; Rustadi Rustadi
Jurnal Geofisika Eksplorasi Vol 5, No 1 (2019)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i1.24

Abstract

The research area "Y" is an area of gold mineralization with low sulfidation epithermal type deposit. The existence of this type of mineralization on the path marked by the presence of mineral deposits, which form the quartz veined below the surface of the deposited within the structure of the fault. In this study, analysis of gravity data using derivatives analysis, i.e. First Horizontal Derivative (FHD) to determine the boundary fault structure and Second Vertical Derivative (SVD) to determine the type of fault. The existence of the fault structure integrated with subsurface modeling results in two-dimensional and three-dimensional. The results showed three line slice made in the area of research, identified structure of down faults (normal) trending northeast - south on slice 1 with an estimated dip (slope) is 22° and expected of strike on this fault is N 158° W and thrust fault structure trending northwest - south on slice 2 also slice 3 with an estimated dip (slope) is 22° and expected of strike on this fault is N 158° E. The results of the modeling of two-dimensional and three-dimensional show fracture structure is at the density of 2 g/cc – 2,67 g/cc in the depth of around 100 m - 250 m that consists of sedimentary rocks (clay and sandstone) with a density of 2,2 g/cc – 2,3 g/cc at the age of Tertiary Pliocene, tuff rock with a density of 2,4 g/cc – 2,5 g/cc at the age of Early Miocene and bedrock (basement) in andesite form with a density of 2,67 g/cc.
APLIKASI METODE GEOLISTRIK RESISTIVITAS KONFIGURASI WENNER- SCHLUMBERGER UNTUK MENGIDENTIFIKASI LITOLOGI BATUAN BAWAH PERMUKAAN DAN FLUIDA PANAS BUMI WAY RATAI DI AREA MANIFESTASI PADOK DI KECAMATAN PADANG CERMIN KABUPATEN PESAWARAN PROVINSI LAMPUNG Wilyan Pratama; Rustadi Rustadi
Jurnal Geofisika Eksplorasi Vol 5, No 1 (2019)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i1.21

Abstract

Research area is located in Padang Cermin Sun-District, Pesawaran Regency, Lampung Province. Manifestation in research area is hot water pool with surface temperatures reach 900C. Data acquisition has been done by Wenner-Schlumberger configuration with 5 acquisition line. Line 1, line 4 and line 5 have 280 meters length. Line 2 have 240 meters length and line 3 have 320 meters length with a spacing of each electrodes in each lines is every 5 meters. The objective of this research are (1)examining the geochemical contaminant and fluid types, (2)identifies the geothermal fluid based on 2D and 3D resistivity data analysis, also (3)identifies the layer of rock in Padok manifestation area based on 2D and 3D subsurface resistivity section. Subsurface lithology in research area generally divides into 4 parts. Which is hot water fluid with mean resistivity value between 1 Ωm into 3 Ωm and based on geochemistry data the fluid type is chloride water; surface sediment with resistivity value between 6 Ωm into 50 Ωm and identified as swamp sediment and alluvium sediment divides into gravels, pebbles, sands, clay and peat; Gravels, pebbles, sands, clay and peat with resistivity value between 50 Ωm into 100 Ωm; and igneous rock (andesite-basalt) with resistivity value more than 100 Ωm.
ANALISIS TINGKAT RESIKO DAMPAK GEMPABUMI DI KABUPATEN CILACAP MENGGUNAKAN METODE DSHA DAN DATA MIKROTREMOR Kukuh Dialosa; Rustadi Rustadi; Bagus Sapto Mulyatno; Cecep Sulaeman
Jurnal Geofisika Eksplorasi Vol 4, No 3 (2018)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v4i3.42

Abstract

Soil mechanical research has been done in Cilacap Regency using DSHA method and microtremor data. This study aims to analyze the local land response to earthquakes based on the dominant frequency parameters (f0), amplification factor (A0), wave velocity VS30 and seismic hazard analysis through deterministic approach. This research uses 193 microtremor measurement points using a short period TDS-303 type (3 component) seismometer. Microtremor data were analyzed using the Horizontal to Vertical Spectral Ratio (HVSR) method in geopsy software. DSHA analysis refers to the source of the Lembang Fault earthquake and Java Subduction zone for deterministic calculations. Based on the analysis of HVSR method, Cilacap Regency is located on land type 1 (frequency 0-1.33 Hz) and soil type 2 (frequency 1,33-5 Hz) according to Kanai Classification (1983), dominated amplification value 1,104 to 8,171 times, then Dominated by soil class E (VS30 value 183 m / s) and soil class D (183 m / s VS30 366 m / s) according to NEHRP Classification (2000). This indicates that Cilacap Regency has high vulnerability to earthquake disaster. Based on the estimated value of PGA calculation method of DSHA, from the calculation of earthquake source Subduction obtained Java PGA bedrock 0,045 g - 0,0671 g and PGA surface rock 0,1926 g - 0,4855 g and calculation of Lembang Fault obtained PGA bedrock 0, 09 g - 0.025 g and PGA surface rocks 0.017 g - 0.089 g. Based on risk map analysis (combination of dominant frequency analysis, amplification, susceptibility factor and ability factor), the highest risk areas are Kec. Adipala, Kasugihan, Binangun, Nusawungun, Cil. Middle, Cil. South, Cil. North, allegedly the soil layer constituent area is a layer of thick and soft sediments. While the low risk of Kec. Majenang and Dayeuh Luhur.
IDENTIFIKASI CEKUNGAN HIDROKARBON “RAE” BERDASARKAN DATA MAGNETOTELURIK DI DAERAH BULA, MALUKU Gita Purna Rae Wanudya; Syamsurijal Rasimeng; Rustadi Rustadi; Noor Muhammad Indragiri
Jurnal Geofisika Eksplorasi Vol 4, No 3 (2018)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v4i3.40

Abstract

The research had been performed using Magnetotelluric to get a 2D model based on variations in resistivity of the subsurface rock. The purpose of this study was to determine the hydrocarbon formation zone. The research method to achieve the research objectives, among others, the first filtering performed on the data with a robust process. This process consists of Robust No Weight, Robust Rho Variance and Ordinary Cohenerency. The second step is done to change the format Selection XPR And Edi. A third inversion resistivity model for the review get a 2D cross section. Based on the findings of the eight data processing methods of measurement points obtained information Magnetotelluric rock formations. Formation hidrokrabon What are the areas is research a reservoir and caprock. The layer in 1600 m – 2700 m depth from the surface which resisvity 12 -33 m assumpted as clay cap. While the layer in 2700 m – 5000 m depth from the surface with high resistivity 41- 250 m is assumpted as oil sands (reservoir). The trap zone of this hidrocarbon formation categorized into structural trap which is the trap of anticline.
PEMETAAN MIKROZONASI DAERAH RAWAN GEMPABUMI MENGGUNAKAN METODE HVSR DAERAH PAINAN SUMATERA BARAT Asri Wulandari; Suharno Suharno; Rustadi Rustadi
Jurnal Geofisika Eksplorasi Vol 4, No 1 (2018)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v4i1.5

Abstract

Regional Painan, the distric of Pesisir Selatan, the province of west Sumatera is one of the areas with high risk disaster prone. This study aims attempts to maped the disaster prone area of the Painan region based on the dominant frequency value, Vs30, PGA and amplification and to know the value of ground movement from the area. By using the HVSR method (Horizontal to Vertical Spectra Ratio) expected to assist to zone the regions. Based on the research that has been done, it is known that the Painan area, West Sumatera, have values of dominant frequency between 0.6 to 12.07 Hz. As for the value Vs30 between 73.08 to 1449 m/s and the amplification values between 0.47 to 6.01. The PGA value for Painan region between 0.034 to 0.063 g. Based on the analysis that has been done by correlating the four zoning map, it is known that the area which has a high risk of earthquake disaster that is estimated to coastal areas. This is supported by the dominant low frequency value and the value Vs30 small and PGA of high value. The amplification value of this region is divided into four zones, areas that have amplification is very high being around the beach and composed by rock alluvial, the value of amplification of high contained in nearly all the regions Painan while amplification medium and low are the small area of Painan and the small area of Bungo Pasang Salido because based on the geological map of the area is composed of two types of rocks are alluvial and rock Painan Formations.
Analisis Penurunan Muka Tanah dengan Small Baseline Subset Differential SAR Interferograms di Kota Bandar Lampung Bagas Setyadi; Rustadi Rustadi
Jurnal Geofisika Eksplorasi Vol 5, No 2 (2019)
Publisher : Engineering Faculty 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.