- Home
- Conferences
- Conference Proceedings
- Conferences
EAGE-HAGI 1st Asia Pacific Meeting on Near Surface Geoscience and Engineering
- Conference date: April 9-13, 2018
- Location: Yogyakarta, Indonesia
- Published: 09 April 2018
21 - 40 of 115 results
-
-
Comparison Analysis Of Subsurfaces Survey Between Geophysics Method (Geoelectric/Ert) And Geotechnical Method (Standard Penetration Test (Spt) At Kaima Overpass Manado-Bitung Toll Road
Authors Abdurrahman Wafi, Panganggit Sasmito, Mohammad Arief Rizki and Arief RahmanSummaryManado-Bitung Toll Road is one of priority projects announced by Indonesia President, Joko Widodo, to speed up economic growth in North Sulawesi Province. Kaima Overpass is one of many overpass which will be built to provide crossing between Manado Bitung toll road and local roads around it. Geo-electric method or known as Electrical Resistivity Tomography is used to get subsurface data and groundwater, while geotechnical method is used to get data about mechanical properties of subsurface material. The purpose of this research is to know the structure subsurface, estimated volume of hard rocks and soft rocks at Kaima overpass location. Kaima overpass location is dominated by medium rocks and hard rocks from Geo-electric data with value greater than 500 Ohmmeter and Standard Penetration Test N-SPT value greater than 15. The subsurface material structure consists of Andesite and Gravel Alluvium, which come from sediment / lava sediment from Mount Klabat.
-
-
-
Determination of Slip Surface area using Geoelectric, MASW, and Soil Mechanics Data in Cimuncang Village, West Java
Authors R.C. Wibowo, B.S. Mulyatno, M. Romosi and A. ZaenudinSummaryThe research of soil movement has been conducted using resistivity method, MASW, and soil mechanical data in Cimuncang, Malausma, Majalengka. The research has done in order to know resistivity distribution value and shear wave velocity VS30, to determine and analyzing rock layers pattern, slip area depth through 2D and 3D modelling result, and analyzing slope Safety Factor (SF) based on soil mechanical laboratory testing. The estimation of resistivity value is done by applying resistivity modelling, the value is vary from 6–200 Ωm which the depth of slip area is 5–7 m. The estimation of shear wave velocity value is done by applying MASW modelling, the value is vary from 40–500 m/s which depth of slip area is about 5 m. The layer that used as slip area based on resistivity modelling is contact between clay (<25 Ωm) and tuff (25–75 Ωm), and based on MASW modelling that considered as slip area is between soft soil layer (VS <183 m/s) and stiff soil layer (VS 183–366 m/s). Based on Geoslope modelling gained slope Safety Factor (SF) is valued 1,26 in southeast that means the slope is relatively stable and in northwest is valued 0,98 that means the slope is unstable area.
-
-
-
Preliminary 1D PS modelling to evaluation oil generation in Wichian Buri sub-basin
Authors C. Chaiyasart and P.H. GiaoSummaryThe Wichian Buri sub-basin of Phetchabun basin, Thailand is reported the significant recoverable hydrocarbon from fractured igneous rock reservoirs but until now no detailed research has been done to estimate the hydrocarbon generation and intrusion effect to maturation. In this study, an integrated approach was proposed and applied both petroleum system modelling (PSM) and hydrocarbon generation to evaluate potential source rock of Wichian Buri unit IV with intrusion effect. The study was conducted base on the data from public domain of petroleum industry in Thailand, including vertical well sections, well logs, regional geological sections, base maps, and geochemical data. The results of petroleum system modelling (PSM) indicated that potential source rock in Unit IV was maturation and generate HC with the effect of igneous intrusion. The Ro of the source rock is 0.62% and hydrogen index of the source rock is 222 mgHC/gTOC. Hydrocarbon generation was found in the late Miocene basalt tertiary and Permo-Triassic Nam Duk formation. Finally, the hydrocarbon generation estimated 1,392.4 - 2,489.7 MMSTB of Wichian Buri unit IV and results of this study concluded that the igneous intrusion effect to immaturities source rock to generate hydrocarbon.
-
-
-
a-Value and b-Value as Basic Calculation Seismicity Index, Repeated Period, and Vulnerability of Earthquakes
Authors A. Arimuko, F. Yoan, S. Rohadi and K. H. C. WulurSummarya-Value and b-Value can be used to basic calculation to get seismicity index, repeated period, and vulnerability of earthquakes in a region. Yogyakarta is a region of Indonesia that often earthquakes are happened, caused by an active fault it has, Opak fault. And also because it is flanked by Java Megathrust and an active volcano. Earthquake phenomenon is very detrimental to life and many casualties if there is no preparedness to deal with it. This research aims to get the calculation results from seismicity index, repeated period, and vulnerability of earthquakes to indicate areas prone of earthquakes in Yogyakarta. The method used is a matrix inverse calculation, Gutenberg-Richter’s (1956) least square equation, to obtain a-value and b-value. This research uses USGS and BMKG earthquake catalog data and classifies it based on the region of Yogyakarta in geodetic coordinates ie 7.493°-11.523°S and 109.841°-110.940°E. The results of this research is got a-value and b-value calculations in Yogyakarta are found a = 4.0866 and b = 0.6528. And from the calculation results obtained that the seismicity index, repeated period, and earthquake vulnerability that occurs is Mw ≥ 5 in Yogyakarta.
-
-
-
Integrating Geophysics, Geology, and Geochemistry Methods for Shallow Biogenic Gas Exploration in Indonesia
Authors Z. Firdaus, R. Muammar and D. RalanarkoSummaryShallow biogenic gas has long known as a drilling hazard in petroleum industry which responsible for several blowouts in the past time. Despite its infamous name in the industry, biogenic gas usually composed of more than 95% methane and it contains considerable amount of global reserve to be produced in a relatively shallow area. In order to turn biogenic gas into a production horizon, different treatments are needed. This research took place in Bentu PSC, Talangjimar Field, and Tunu Field which are distributed in Central Sumatra Basin, South Sumatra Basin, and Kutai Basin respectively. By integrating AVO analysis (geophysics), burial history and geothermal gradient (geology), as well as carbon isotope and gas composition (geochemistry), one can easily detect the presence of biogenic gas in the subsurface area along with its origin and quality. Our investigation suggested that by combining the three geosciences elements, the chance of exploration success may increase significantly, leading to the addition of biogenic gas reserve to be produced in the future.
-
-
-
The Influence of Focal Mechanism to the Tsunami Wave Height of the Simeulue Aceh Earthquake on April 11, 2012
Authors U.I. Nurdiana, F. Purnamasari and A. NurokhimSummaryEarthquake in Simeulue Aceh happened on April 11, 2012, at 08:39:31 GMT with latitude coordinates 2.35° and longitude 92.82° with magnitude 8.6 Mw. This earthquake occurred at a depth of 45.6 km. Because of this earthquake, the tsunami was recorded in several places. Meanwhile, a small tsunami reportedly hit the island of Simeulue that dragged objects to the coast and created 3 meters height waves in the Gulf of Sibigo, West Simeulue. The April 11, 2012 Simeulue Aceh earthquake was the largest earthquake caused by a strike-slip fault. This earthquake was categorized as an outer-rise quake because it was located outside the subduction zone. The April 11, 2012 Simeulue Aceh earthquake was dominated by horizontal (strike-slip) component, where the horizontal component was dominant, so it did not generate the large tsunami waves. The tsunami propagation models also different between the tsunami model without the focal mechanism and with the focal mechanism (we used strike 20 and 289). From 2 data station, Sabang and Nancowry validation result, then compared the observation result with IOC data, so we know that the height of tsunami was influenced by focal mechanism, in this case, the strike 289 is the nearly compatible with IOC data.
-
-
-
Volumetric Calculation Based On Comparative Resistivity Imaging Analysis Between Marquadt And Occam Inversion: An Andesite Quarry Case Study
Authors Aditya Aries Furkhan, Agra Adipta and Wrego Seno GiamboroSummaryVolumetric determining in mining prospect encounters certain biases. Resistivity imaging was comprehended to determine the resistivity distribution of the andesite body. Inversion is used to characterize a subsurface properties upon the geological condition. Inversion data are transformed into model parameters which could explain the possible subsurface properties that may cause the data be obtained based on the acceptable forward formulation ( Martakusumah and Srigutomo, 2015 ). Marquadt and Occam inversion are non-linear inversions with a linear approximation. Both of inversions are used on the resistivity data resulting a comparative resistivity model. The result from Marquadt inversion suites more with the geological condition, in contrary with Occam inversion. Andesite body identified as a high resistivity value ranging 400 – 2000 Ω.m. Marquadt inversion portray intrusion shaped andesite with a volumetric reaching 9,987 x 106 m3.
-
-
-
Surface deformation monitoring of Mt. Agung by Sentinel-1 DInSAR
SummaryPhreatic eruption occurred on November 21, 2017 on Mount Agung with the ash cloud reaching the height more than 3,800 meters. This was followed by multiple magmatic eruptions occurred since November 25 to 27. Volcanic activity has been weakened after November 29, but it is still continuing.
In this study, recent status of the surface deformation of Mt. Agung, detected by DInSAR using Sentinel-1 satellite data, is reported. Preliminary results indicate that no deformation occurs before the phreatic eruption, but after the eruption a swell on northern slope may occur.
-
-
-
3D joint inversion of gravity and magnetic data based on structure similarity of node physical property model
Authors S. L. Li, N. P. Wang, X. H. Meng and J. WangSummaryThe node physical property model with good sparseness is the difference form of its corresponding block physical property model. It can not only eliminate computational redundancy and improve the efficiency of forward computation, but also can effectively recover simple geology models. The developed gravity-magnetic simultaneous inversion method introduces the structure similarity constraint between two node physical property models to make the inversion results have the characteristics of structural consistency. The Cauchy norm constraint can be used to get a sparse solution. Within the conventional inversion framework, this strategy does not need to apply nonlinear functions such as physical property transformation function to overcome the problem of nonlinear enhancement, and the inversion results are not affected by the initial value. The model tests show that the inversion method can effectively recover simple geology models. The boundary of the recovered anomalies is clear and the location is close to the real position. The block physical property values of the recovered anomalies are also closer to their true values. Compared with the inversion using only one geophysical method data, the joint inversion improves the vertical resolution of anomalies to a certain extent, and inhibits the generation of partial interference anomalies.
-
-
-
Seismic Wave Modeling of Numerical Dispersion using Cross-rhombus Stencil
Authors A.D. Sonya and T.A. SannySummaryFinite difference is a popular method that used for seismic wave modelling, but it still suffer from numerical dispersion problem. Stencil is one of finite difference aspect that affect its accuracy, including the dispersion. Cross-rhombus stencil is a new stencil scheme which combine the standard stencil and a diamond-shaped stencil called rhombus stencil. It is proved that it can reduce numerical dispersion in finite difference method and increasing its efficiency. Since it is new scheme, cross-rhombus stencil has a lot of things to be studied. We described basic theory of this stencil scheme and its application to a simple seismic modeling simulation.
-
-
-
Surveying the layers of pavement using ground-penetrating radar
Authors K. Onishi, H. Kisanuki, T. Ogahara and T. InazakiSummaryMulti-channel GPR with ground coupled antennas can acquire underground records with little amount of multiple reflections. We use multi-channel GPR equipment, which can scan at high speed on a paved road, to acquire underground survey records at a test road which has many sections composed of different type of materials and depths. The records clearly indicate horizontal boundaries of road construction without processing of background removal. We acquired zero-offset profiles applying normal moveout (NMO) correction for GPR records. NMO correction is useful to detect the shallow boundary below asphalt concreate mixture. GPR with bow-tie antenna of ground coupled type, which can scan on paved road at high speed has high potential to monitor the condition of road construction.
-
-
-
Large 3D resistivity and IP measurement of the Séchilienne landslide using the FullWaver system
Authors C. Truffert, P. Nevers, M. Lajaunie, J.P. Malet, C. Bertrand, J. Gance and O. LeiteSummaryLa Séchilienne is a hudge deep seated landslide located in the French Alps. Authors will present a full 3D Electrical Resistivity Tomography (ERT) performed with the FullWaver(c) system designed by Iris Instruments. This distributed, autonomous and cable free solution allows to restitute a 3D distribution of resistivities useful for a better understanding of the geometry and the processes of the landslide.
-
-
-
Paper Title for Landslide Identifications Based on Geology and Geoelectricity Mapping Analysis, Study Area: Road Province Pacitan-Ponorogo, East Java, Indonesia.
Authors L. R. Daryono, A. Hendratno, M. Nukman and E. HartantyoSummaryUnderstanding of landslide mechanism was imperative to appropriate the mitigation geotechnical methods. Engineering geological investigation and geoelectrical dipole-dipole resistivity analysis were carried out in the studied area to elucidate the mechanism of the landslide. The engineering geological investigation consists of local topographical mapping. The geoelectrical dipole-dipole resistivity analysis assessment of the problems affected landslide was conducted by a sub-surface imagine using resistivity contrast. The results presented in this paper successfully detect fractures at various depths and their position with the resistivity low contrasts as claystone is among the high-resistivity zones (volcanic rock). Low resistivity zone has a pattern with a slope of ∼45 degrees to the East and acted as field shear-surface the movement of soil in landscape survey. Interpretation of resolution lithology and shear-surface fields ranging between 25 – 30 m.
-
-
-
Integrated Remote Sensing and Geological Mapping to Identify Landslide Prone Zone in Loano, Purworejo, Central Java
Authors I. D. Puta, A. Hirawan, R. Abbas and A. D. TitisariSummaryLandslide is one geological disaster with a high risk that often occurs in Central Java Province, including in the Loano Area, Purworejo District. .Today there are many people in Loano who dwell in areas prone to landslide. However, it is necessary to conduct integrative research activities as a form of disaster mitigation to reduce the landslide risk. Research conducted in the form of remote sensing, geological mapping and GIS (Geographic Information System) analysis. Remote sensing observation shows that the factors control the Landslide are the presence of non vegetation in the southeast and west side of the areas, the slope (<15O), less crystalline rocks, geological structure, and hydrothermal alteration minerals.The lithology is composed of 4 rock units: basaltic andesite, andesite, tuffaceous sandstone and andesite breccia. The alteration zone lies in the unit of andesite lava lithology. The various clay minerals minerals in the form of illite, smectite, and kaolinite are the result of hydrothermal alteration which can be classified as an argillic type. There are 10 points of landslide prone zone. The zone is characterized by a slope above 15o and a high alteration level. Highfall rate of rainfall (131 – 241mm/month) in Kulonprogo area also believed control the landslide.
-
-
-
Identification of Landslide Vulnerability Using Seismic Refraction and MASW: Study Case in Kulonprogo, Indonesia
Authors H. S. Mahandani, K. S. Brotopuspito and A. AnggrainiSummaryResearch on landslides has been done in Purwosari Village, Girimulyo Sub-district, Kulonprogo Regency with Seismic Refraction and MASW’s methods. The study consists of 20 Seismic lines to determine the level of landslide vulnerability in the researh area. Vp and Vs values obtained are then used for calculating the elastic properties of rocks in the weathered layers. Result of the analysis shows that the most vulnerable area of landslides is in District of Gedong in Purwosari Village which is located in North-West of the research area. This area has a low Vp, Vs, density, Shear and Young’s Moduli with high Poisson’s ratio indicates that the area is water saturated. Water saturated slope will have lower frictional force that makes the weathered layer prone to landslide.
-
-
-
Estimation of Aquifer Properties Using Surface Based Electrical Resistivity Tomography
Authors T. Fadilah, L. Gross and R. SchaaSummaryAquifer characterization such as hydraulic conductivity (K) is necessary due to groundwater sustainability for agriculture industry. The current method for calculating K is to conduct a pumping test or a permeability test. This study is trying to find an alternative method to obtain a K value by determining the correlation between water and aquifer resistivity which is conducted in the laboratory and field scale. The aquifer resistivity is gathered from Electrical Resistivity Tomography (ERT) and the water resistivity from direct measurement. The correlation can perform the Kozeny–Carman equation, which is modified from Archie and Waxman–Smits formulas, to estimate the hydraulic conductivity. The hydraulic conductivity estimation is compared with the hydraulic conductivity value from the permeability and pumping test solutions. The measurement result showed 12.63 m/day, which was similar to the permeability test with 10.3 m/day. However, the field result revealed 14.07 m/day, while the pumping test indicated 24.5 m/day. An analysis has been conducted with the fact that geological condition, grain size, and water resistivity have a significant contribution to the result. Nevertheless, the outcome of the ERT profile can be an alternative method to get an estimation of K that is more efficient, yet not offensive.
-
-
-
Resistivity Method with Werner-Schlumberger Configuration to Analysis Seawater Intrusion at Teluk Betung Area, Lampung
Authors Taufiq, H.D. Mega and A. ZaenudinSummaryTeluk Betung area is an area in the southern coastal of Bandar Lampung city directly adjacent to the sea. Based on a survey of residents wells in the area, indicating that the groundwater in this area has been contaminated by seawater (brackish) so it is not suitable for consumption. This occurs because of the increased need for fresh water in proportion to increase of population in the region resulting in ground water exploitation continues to increase every years. The reduced water content in the soil may result in the entry of the aquifer layer of seawater into the aquifer zone and contaminate ground water, this condition is often referred to as seawater intrusion. To mapping the pollution zone caused by the seawater intrusion we used resistivity method.
-
-
-
The Groundwater Survey by using Resistivity Method and its Application in the Republic of Rwanda
Authors K. Nakamura, T. Aizawa and S. MatsudaSummaryThis paper presents result of the groundwater survey by using resistivity method and its application especially in the developing countries based on the lessons learnt through the feasibility study of irrigation facility rehabilitation project in Republic of Rwanda in eastern Africa.
As a result of the study, the water catchment structure was examined by resistivity survey, and availability of water resource was also confirmed. In addition, it was confirmed that the interpretation of the resistivity survey results for the water catchment structure in the laterite soil of this country is appropriate. This suggests that there is sufficient possibility of project cost reduction due to early implementation of resistivity survey. In the future, it is considered that similar interpretations can be made in the case of constructing an alternative water facility in the vicinity of a place already having a spring as in this time.
-
-
-
Search for and investigation of volcanoes with gravity surveys
By J. MrlinaSummaryGeophysical methods, mainly gravimetry and magnetometry, can serve as suitable tools for location of unknown hidden volcanic structures that are not expressed by any typical topographic features. These may be e.g. diatremes and maars with eroded scoria cones or rims of tuff/tephra material, as well as lava flows.
Gravity survey may reveal significant negative anomalies due to low density of the filling of volcanic vents, or positive anomalies over the bodies of compact lava accumulation. Magnetometry would rather show positive anomalies related to most of the volcanic structures due to high content of magnetic minerals in the volcanic rocks (except acid trachytes/phonolites/rhyolites). Geophysical surveys should therefore form part of any investigation of volcanic fields where some unknown volcanoes may still be expected.
Gravity monitoring can reveal hidden mass and fluids movement in a volcano interior, and can therefore contribute to the hazard control at regions with active volcanoes.
-