Identifikasi Bidang Gelincir Pemicu Tanah Longsor dengan Metode Resistivitas 2 Dimensi di Desa Trangkil Sejahtera Kecamatan Gunungpati Semarang

Landslides was happened by landslide surface. Landslides Identification of landslide surface using dipole-dipole array geoeletrical resistivity 2D method has been conducted at Trangkil Sejahtera Sukorejo Village Gunungpati Regency Semarang. Interpretation of subsurface structure showed in 2D. Field data has processed using RES2DINV program which gives stones resistivity distribution and depth of layers as a result. The result of RES2DINV is entered to CorelDraw to obtain 3D section. Landslide surface has detected by CorelDraw result\u27s. The interpretation show that at Perumahan Trangkil Sejahtera lithology consist of four layers i.e. sandstone, clay/lanau, wet clay, and topsoil. Slip surface was located on lanau/wet clay layers with resistivity 0,492-9,11 Ωm and dept of layers 2,65-6,47 m. Type landslides research area is kind of translational and rotational slides

Interpretasi Struktur Bawah Permukaan Daerah Manifestasi Mineral Emas Sistem Epithermal dengan Metode Polarisasi Terimbas (Induced Polarization) di Daerah “X” Kabupaten Garut Jawa Barat

A geophysical investigation has been done using Induced Polarization Method at area “X”, Garut, West Java. The purpose of this investigation is to identify the sub-surface stucture of a minerals gold epithermal system manifestation area.The research area is a gold prospect area which is a mining concession area ofAneka Tambang, Tbk. Stratigraphy lithology constituent part of the study area Jampang Formation which consists of andesite lava, andesite breccia, hornblende, and fine tuffaceous rocks. Induced Polarization method is usingelectrical properties of rocks by detecting the electrical polarization on the surface of metallic minerals beneath the earth\u27s surfaceThe processed data is measured with Dipole-dipole configuration, with electrodes spaced 25 meters. Path length 200 meters, so the expected penetration depth reaches 600 meters. Data processing use software AGI EarthImager2D and Geosoft , is obtain imaging the model 2D and 3D subsurface. The processing results is present in 2D and 3D, From the modeling results indicate that the tuff and Crystallin Tuff rock and minerals sulphide (si-ka-il, ka-il) with resistivity values ranging from 150 to more than 1000 ohm.m ohm.m and chargeabilitas values ranged from 100 ms to more than 300 ms, distribution pattern is decreased from north to south and then to east in penetration depth reaches 600 meters of subsurface.Volume for estimated potential of minerals gold epithermal system manifestation is 161.302.421,7 m

Identifikasi Jenis Batuan Candi Dukuh, Candi Ngempon dan Candi Gedong Songo Menggunakan Sonic Viewer-sx 5251

Rock identification with rock mechanics properties of rock samples to determine the type of Dukuh temple , Ngempon temple and Gedong songo temple, with the ultrasonic wave method using Sonic Viewer SX - 5251. Travel time of ultrasonic waves on the sample is used to obtain S and P wave velocity. Data has processing using Excel software. Value of the S and P wave velocity, shear modulus , rock elasticity , and Poisson 's Ratio will be correlated with rock density tables, P and S wave velocity tables and rock mechanics properties table it can be seen kind of rock from each of the rock physics properties. The research result shows that rock composite Ngempon temple, Dukuh temple , and Gedong Songo are Andesite. In addition to the density values which obtained, the level of rocks weathering can be defermind as well. Dukuh B rock sample with a density of 2.66 gm /cm3 can be classified in level I, it show that those rocks are strong and good. On the other samples of the Ngempon temple, gedong Songo or from another Dukuh the density values which obtained are from 2.33 to 2.49 can be classified at level II or it can be said to be strong enough

Pemodelan Struktur Bawah Permukaan Daerah Sesar Jiwo Klaten dengan Metode Medan Magnet Total

This study, using the method of total magnetic field in the area of ​​Central Java Klaten, aims to interpret the subsurface structure of the fault zones surrounding Prambanan, Wedi, and Gantiwarno district that became the suspect of the aftershocks cause occurring on May 27, 2006. The total magnetic field measurements use GSM19T Series magnetometre with the accuracy of ± 0.5 nT which includes 158 points. From the interpretation result using the second vertical derivative analysis, it can be known that there are three fault areas which are categorised as normal faults. The first fault is found in the volcanic rocks composed by the layers of volcanic breccia, lava and tuff. It is characterised by a change in the susceptibility value from 0.3 to 0.2 cgs. The second section is in Kebo Butak rock formation comprising the layers of sandstone, clay, silt, and algomerat. It is characterised by changes on the susceptibility values from 0.126 to 0.007cgs and from 0.33 0.126 cgs. The last fault is located in the Semilir formation consisting of tuff rocks, pumice breccias and tuffaceous sandstone marked by changes on the susceptibility values ​​from 0.25 to 0.1 cgs and from 0.5 to 0.25 cgs

Analisis Kerentanan Airtanah terhadap Pencemaran di Dataran Alluvial Kota Semarang Menggunakan Metode God dengan Memanfaatkan Data Resistivitas dan Data Hidrogeologi

Groundwater is the water resources necessary for living things and the most desirable human. Groundwater needs to increase as the population increase. One example is in the Alluvial Plain of Semarang. To supply water necessary, the population use a tap of aquifer shallow wells. Shallow aquifer vulnerable to contamination due to the effect of shallow depth and human activities. Therefore there is a needed to conduct for research on the groundwater vulnerability due to contamination. GOD is the system to determine of value groundwater vulnerability due to contamination. The parameters used are the type of aquifer (G), type of lithology aquitard (O), and the depth to groundwater table (D). These three parameters derived from resistivity data and hydrogeology data. The results of the analysis by this method has three levels of vulnerability of groundwater due to contamination the area of the vulnerability of low, moderate, and high. So it is recommended that the analysis can be made of the green open area to reduce contamination and groundwater catchment area is formed, and restrict the activities to achieve economic gains and reduce the danger of environmental contamination

Analisis Intrusi Air Laut Meggunakan Data Resistivitas dan Geokimia Airtanah di Dataran Aluvial Kota Semarang

Emarang lowland-alluvial area is in the state of salt water intrusion, that has a direct impact to the groundwater quality. Groundwater quality is not only triggered by water level decreasing factors due to the groundwater exploitation,but also by the factor of lithology and aquifer condition. The purpose of this research is to know the resistivity rocks value, the value of groundwater quality, and to analyze the distribution of the estimated area that has been instuited by salt water. The result of processed data with Progress 3.0 is in the form of resistivity value which is correlated with groundwater quality testing value with salinity, electrical conductivity, dissolved oxygen, andpH parameters. Based on the geo-resistivity and groundwater geochemical data shows that there is intrusion salt water distribution area which occur in Trimulyo area with the resistivity value of 0,27 Ωm as the indicator of salinity and groundwater quality value parameters which show the salinity value of 3.600 mg/L, electrical conductivity of 6.370 μS/cm, dissolved oxygen of 0,8 ppm, and pH 7,7

Analisis Porositas dan Saturasi Air dalam Integrasi Petrophysics dan Seismic Multiattributes untuk Karakterisasi Reservoir

Plan of Development I is the development plan of one or more oil and gas fields in an integrated way (integrated) to develop and produce hydrocarbon reserves. Field development was conducted in order to know the area indications of hydrocarbons based on petrophysics analysis and determine its content with multiattributes. By integrating the study of seismic data, well data (including petrophysical analysis) with geological and stratigraphic information is a necessary step to determine the characteristics of a reservoir. Formation evaluation and petrophysical analysis as an initial stage to characterize the reservoir by studying rock properties such as volume of clay, porosity and water saturation. Multiattribut seismic analysis is used to predict the physical properties of the rock as a whole in the seismic volume. Based on the results of the petrophysical analysis of the target porosity ranges from 11% -14%, from the netpay statistical data lumping results have value Net to Gross range of 7% to 40%.and water saturation ranging from 18% -38%. Seismic multiatributtes method can predict petrophysical analyzes well in the target zone

Interpretasi Struktur Bawah Permukaan Berdasarkan Data Geomagnetik pada Daerah Mata Air Panas Jatikurung Kabupaten Semarang

The interpretation of subsurface structure and the identification of caused of the hot springs Jatikurung by using magnetic method have been successfully carried out. In this study, magnetic data acquisition was carried out in 71 points by using a PPM (Proton Precession Magnetometer) geometrics type of GSM 19T models to get the values of the total magnetic field. Data processing began with IGRF (International Geomagnetic Reference Field) correction and diurnal correction to get the total magnetic anomaly. The corrected data has been used to create total magnetic anomaly contour. The total magnetic anomaly contour has been used to process reduction to plan surface. The result of reduction to plan surface has been used to create a contour upward continuation and then made reduction to the poles. The result of research showed the total magnetic anomaly closure pair of positive and negative indicated a fault zone below the surface. The closure pair of positive and negative close to the manifestation was made an incision to determine the subsurface structure of the region by creating a model of 2-dimensional (2D) using software Mag2DC. In 2D modeling result show that there was a fault zone about 1200 meters depth. At a depth of 326 to 1200 meters was interpreted as a cap rock with a value 0.2926 (SI). The exhibition of the hot springs Jatikurung was interpreted by the finding of adjacent fault with igneous intrusion which was estimated to save the residual of magma that can be used as a heat source