scholarly journals INTERPRETASI SISTEM PANAS BUMI SUWAWA BERDASARKAN DATA GAYA BERAT

2020 ◽  
Vol 5 (2) ◽  
pp. 44-54
Author(s):  
Dian Nur Rizkiani ◽  
Rustadi Rustadi
Keyword(s):  
Hot Springs ◽  
Bouguer Anomaly ◽  
Ground Surface ◽  
Research Area ◽  
Geothermal System ◽  
Svd Analysis ◽  
Free Air ◽  
Tentative Model ◽  
System Data ◽  
Andesite Lava

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.

scholarly journals Hydrogeochemical Characterization of GeothermalWater in Arjuno-Welirang, East Java, Indonesia

2018 ◽  
Vol 2 (2) ◽  
pp. 48
Author(s):  
Vanadia Martadiastuti ◽  
Agung Harijoko ◽  
I Wayan Warmada ◽  
Kotaro Yonezu
Keyword(s):  
Water Samples ◽  
Hot Springs ◽  
Shallow Groundwater ◽  
Thermal Waters ◽  
Geothermal System ◽  
Volcanic Complex ◽  
Geothermal Fluids ◽  
Geothermal Fields ◽  
System Data ◽  
Hydrogeochemical Characterization

Arjuno-Welirang Volcanic Complex (AWVC) is one of geothermal fields whichlocated in East Java province, Indonesia. It belongs to a Quarternary volcanic arc and has potential for development of electricity. The field is situated in a steep volcanic terrain and there are only few geothermal manifestations, i.e., hot springs, fumaroles, solfataras, steaming ground and hydrothermal alteration. This study aims to classify the type and source of geothermal fluid and to estimate the reservoir condition of Arjuno- Welirang geothermal system. Data are obtained from collecting water samples including hot springs, cold springs, river waters and rain water, then they are analyzed using ICP-AES, titration and ion chromatography.All thermal waters have temperatures from 39.5–53°C and weakly acidic pH (5.2–6.5). Cangar and Padusanhot springs show bicarbonate water, formed by steam condensing or groundwater mixing. On the other hand, Songgoriti shows Cl-HCO3 type, formed by dilution of chloride fluid by either groundwater or bicarbonate water during lateral flow. All of the waters represent immature waters, indicating no strong outflow of neutral Cl-rich deep waters in AWVC. Cl/B ratios show that all water samples have a similar mixing ratio, showing they are from common fluid sources. However, Padusan and Songgoriti have higher Cl/B ratios than Cangar, suggesting that geothermal fluids possibly have reacted with sedimentary rocks before ascending to the surface. All waters were possibly mixed with shallow groundwater and they underwent rock-water reactions at depth before ascending to the surface. An estimated temperatures reservoir calculated using CO2 geothermometer yielded temperatures of 262–263 °C based on collecting of fumarole gas at Mt. Welirang crater. According to their characteristics, Cangar and Padusan are associated with AWVC, while Songgoriti is associated with Mt. Kawi.

scholarly journals Hydrogeochemistry of Natar and Cisarua Hot springs in South Lampung, Indonesia

2019 ◽  
Vol 4 (3) ◽  
pp. 178
Author(s):  
Mochamad Iqbal ◽  
Bella Restu Juliarka ◽  
Wijayanti Ashuri ◽  
Bilal Al Farishi
Keyword(s):  
Metamorphic Rock ◽  
Meteoric Water ◽  
Hot Springs ◽  
Hot Spring ◽  
Isotope Analysis ◽  
Research Area ◽  
Geothermal System ◽  
13C Isotope ◽  
Geologic Map ◽  
Quaternary Volcanic Rock

Natar Hot Spring is one of the geothermal manifestations that is located in Lampung Province, Indonesia. About 6 km to the east, another hot spring appears with temperature around 40°C with neutral pH called Cisarua Hot Spring. The Natar Hot Spring itself having temperature 47-54°C with 6.23 pH. Based on the geologic map, the appearance of these hot spring is caused by Lampung-Panjang Fault which trending northwest-southeast. Morphology of the research area is showing a flat terrain topography which composed of Quaternary volcanic rock and metamorphic rock in the basement. The nearest volcano that expected to be the heat source of the geothermal system is the Quaternary extinct volcano called Mt. Betung which is located about 15 km to the southwest. The aim of the study is to analyze the geochemistry of the manifestations and calculate the reservoir temperature. Geochemistry analysis result shows both manifestations are bicarbonate which is formed as a steam-heated water or steam condensates. Geothermometer calculation shows that the geothermal reservoir has temperature 150-160°C with approximately 300 m in depth. All manifestations are originated from meteoric water according to stable isotope analysis D and δ18O data and interacting with carbonate-metamorphic rock beneath the surface based on 13C isotope value. A further geophysics study is needed to determine where the heat comes from.

scholarly journals Identification of Geothermal Potential Based on Fault Fracture Density (FFD), Geological Mapping and Geochemical Analysis, Case Study : Bantarkawung, Brebes, Central Java

KnE Energy ◽  
2015 ◽  
Vol 2 (2) ◽  
pp. 141
Author(s):  
Oktoberiman . ◽  
Dimas Aji Ramadhan P ◽  
Fajar Rizki W ◽  
Rizal Tawakal A
Keyword(s):  
Alternative Energy ◽  
Hot Springs ◽  
Major Ions ◽  
Research Area ◽  
Geological Mapping ◽  
Hot Water ◽  
Geothermal System ◽  
Geochemical Analysis ◽  
Fracture Density ◽  
Geothermal Potential

<p>Insufficient of conventional energy production today in Indonesia, encouraging all elements to discover an alternative energy. Geothermal is one of big potential alternative energy in Indonesia regarding the conditon of geological setting in Indonesia which has 129 active volcanoes. Bantarkawung is located in the western of Mount Slamet where hot spring occured as geothermal manifestation. This indicate geothermal potential in that area. This research is aimed to identify geothermal potential that lies in bantarkawung using Fault Fracture Density (FFD), Geological Mapping and Geochemical analysis. Based on FFD analysis known that anomaly area is located at central and northeast of research area, and based on geological mapping known that area composed by mudstone unit and sandstone unit, water temperature of research area is 43 °C to 62 °C, by using geochemical analysis of major ions HCO3-,Cl-,S042- known that the type of hot water is bicarbonate water which characterized as an outflow zone of geothermal system. </p><p><strong>Keywords</strong>: Bantarkawung; FFD; geochemichal analysis; geothermal; hot springs</p>

scholarly journals IDENTIFIKASI KEBERADAAN BASEMENT DI BAWAH CEKUNGAN TIMOR BERDASARKAN DATA ANOMALI GRAVITASI DENGAN PEMODELAN TIGA DIMENSI

2018 ◽  
Vol 3 (1) ◽  
pp. 1-11
Author(s):  
Aryanti Irnawati Pellokila ◽  
Jehunias L. Tanesib ◽  
Bernandus Bernandus
Keyword(s):  
Remote Sensing ◽  
Gravity Field ◽  
Oil And Gas ◽  
Bouguer Anomaly ◽  
Research Area ◽  
Average Density ◽  
Free Air ◽  
Natural Energy ◽  
Remote Sensing Satellite ◽  
The Difference

ABSTRAK Metode Gravitasi adalah metode yang digunakan untuk mencari perbedaan nilai gravitasi dari satu titik ke titik yang lain di suatu tempat yang disebabkan oleh distribusi massa yang terdapat di bawah permukaan daerah penelitian. Telah dilakukan identifikasi keberadaan basement terhadap data anomali Bouguer lengkap di Cekungan Timor dengan posisi geografis 9.40 LS – 10.40 LS dan 123.50 BT – 125.40 BT. Identifikasi keberadaan basement di bawah Cekungan Timor dilakukan berdasarkan data anomali medan gravitasi. Data anomali medan gravitasi yang digunakan dalam penelitian adalah hasil pengukuran Geodetic Satellite dan European Remote Sensing Satellite yang telah terkoreksi hingga koreksi udara bebas. Berdasarkan hasil inversi 3D, densitas rata-rata secara keselurahan dari lapisan pertama hingga lapisan kesepuluh adalah 2.662 . Cekungan Timor yang merupakan sebuah tempat terakumulasinya sedimen dan memiliki basement yang merupakan jenis batuan metamorf dari kedalam 3.86 km hingga 20 km yang kuat dan bersifat tidak meloloskan air maka cekungan ini diduga memiliki potensi adanya jebakan sumber energi alam berupa minyak dan gas. Kata kunci: Gravitasi, batuan dasar, Cekungan, anomali Bouguer lengkap, densitas, pemodelan. ABSTRACT Gravity method is a method used to find the difference of gravity value from one point to another in a place caused by mass distribution which is below the surface of research area. Basement identification of complete Bouguer anomaly data has been done in the Timor Basin with geographical position 9.40 LS – 10.40 LS dan 123.50 BT – 125.40 BT. The identification of the basement under the Timor Basin is based on gravity field anomaly data. The gravity field anomaly data used in the research is the result of measurement of Geodetic Satellite and European Remote Sensing Satellite which has been corrected to free air correction. Based on the inversion, the overall average density from the first layer to the tenth layer 2.662 . Timor Basin which is a place of accumulation of sediment and has a basement which is a type of metamorphic rocks from within 3.86 km to 20 km strong and is not pass the water hence this basin has the potential of a trap of natural energy sources in the form of oil and gas. Keywords: Gravity, Basement, Basin, complete Bouguer anomaly, density, modeling.

scholarly journals Application of MT dan Gravity Method to Potential Analysis of Kepahiang Geothermal Bengkulu

2018 ◽  
Author(s):  
ahmad zarkasyi ◽  
Boko Nurdiyanto ◽  
yunus daud
Keyword(s):  
Hot Springs ◽  
Ground Surface ◽  
Reservoir Rock ◽  
Geothermal System ◽  
Physical Parameters ◽  
Reservoir Temperature ◽  
Geothermal Potential ◽  
Cap Rock ◽  
Residual Heat

An analysis of geothermal potential in Kepahiang-Bengkulu area using gravity and MT measurements of PSDG has been done. The analysis was conducted on 286 gravity points and 37 MT points spread over the southern part of Mount Kaba to Babakan Bogor hot springs. Kepahiang geothermal system is related to the volcanic activity of Mount Kaba which is still preserving the residual heat from the magma. Based on the gravity residual anomaly, the structure that controls the emerging Sempiang hot springs is estimated to be Sempiang fault that in near north-south direction, while Babakan Bogor hot springs is estimated to be controlled by the Sumatra fault. The cap rocks scatter around Sempiang hot springs start from nearground surface with thickness of between 1500 meters to 2500 meters. Cap rock is a unit of Young Lava of Kaba with resistivity &lt; 10 Ohm-m and density is 2.2 gr/cm3. Geothermal reservoir is estimated to be located under the cap rocks scatter around Sempiang hot prings as indicated by values of 10-60 Ohm-m in resistivity and density is 2.4 gr/cm3. The top of reservoir is estimated to be 1500 meters below the ground surface, these rocks are volcanic products of Old Kaba in form of either lava or pyroclastic. Kepahiang geothermal prospect area scatters 19 km2 wide around Sempiang hot springs which is bound by contrast resistivity and fault. It has potential geothermal of 133 MWe with the assumption of reservoir temperature (geochemistry) is 2500C. Calculation of geothermal potential is included in the classification of expected reserves, as well as the extent and thickness of reservoir rock and fluid physical parameters are estimated based on data integrated geosciences detail depicted in the model tentatively.

scholarly journals Identification of Subsurface Structures of Geothermal Potential Area in East of Mount Lawu Using The Gravity Method

2020 ◽  
Vol 10 (01) ◽  
pp. 65
Author(s):  
Sorja Koesuma ◽  
Mela Budiani Septianingsih ◽  
Budi Legowo
Keyword(s):  
Volcanic Rocks ◽  
Bouguer Anomaly ◽  
Research Area ◽  
Earth’S Gravity Field ◽  
Gravity Method ◽  
Subsurface Structures ◽  
Eastern Flank ◽  
Free Air ◽  
Geothermal Potential ◽  
Terrain Corrections

<p>Information about the eastern side subsurface stones of Mount Lawu regarding geothermal potential is limited. This research was conducted to provide information regarding geothermal potential in those area by using the gravity method. We did a 18 sites of gravity surveys in eastern flank of Mount Lawu where located in Magetan regency, Ngawi regency and Sragen regency, East Java. The principle of this method is to measure the earth's gravity field, then the value of gravity is corrected by some gravity corrections, i.e. height, tide, drift, normal gravity, free-air, Bouguer and terrain corrections. The Complete Bouguer Anomaly (CBA) shows the formation that related to the rock formation in the subsurface of Mount Lawu. Based on CBA modelling we found that in the eastern flank of Mount Lawu contains of tuff and breccia of volcanic rocks, breccia Jabolarangan and tuff Jabolarangan, lava andesite, igneous rock (pumice), and sedimentary rocks in the form of sandstone and clay. We found a fault structure on six tracks of a research area. Otherwise, we estimated that there is a geothermal potential on the southeast side of the research area</p>

scholarly journals Identification of Subsurface Rock Structure of Non-Volcanic Geothermal Systems Based on Gravity Anomalies (Terak Village, Central Bangka Regency)

2021 ◽  
Vol 5 (2) ◽  
pp. 539-543
Author(s):  
Reza Firdaus ◽  
Siska Oktaviyani ◽  
Putri Hardianti ◽  
Tri Kusmita ◽  
Anisa Indriawati
Keyword(s):  
Hot Springs ◽  
Continuation Method ◽  
Bouguer Anomaly ◽  
Gravity Anomalies ◽  
Hot Water ◽  
Reservoir Rock ◽  
Geothermal System ◽  
Geothermal Systems ◽  
Rock Structure ◽  
Free Air Anomaly

Abstract   Geothermal manifestations on Bangka Island are found in the villages of Terak, Pemali, Sungailiat/Pelawan, Dendang, Permis, and Nyelanding. The manifestation of hot water in Terak Village, Central Bangka Regency is in the form of 3 hot springs with a surface temperature of 55ᵒC this research is to be carried focus on the structure of the subsurface rock layers using the geophysical method, namely the gravity method. The data used are topography and Free Air Anomaly. The data processing is in the form of Bouguer Correction and Terrain Correction to obtain the Complete Bouguer Anomaly (CBA) value. Then the CBA value is separated from regional anomalies and residual anomalies using the upward continuation method, as well as 2D modeling interpretation (forward modeling). From the research results, it is known that the subsurface rock structure of the non-volcanic geothermal system in Terak Village in the form of sandstone (2.28 – 2.49 gr/cm3) at a depth of 0 – 1.44 km is estimated as caprock, granite (2.77 – 2.78 gr/cm3) at a depth of 0 – 1.8 km is estimated as reservoir rock, and diorite rock (2.87 – 2.99 gr/ cm3) at a depth of 0 – 2 km is estimated as basement rock.    

Optimal Density Determination of Bouguer Anomaly Using Fractal Analysis (Case of study: Charak area,IRAN)

2005 ◽  
Vol 1 (1) ◽  
pp. 21-24
Author(s):  
Hamid Reza Samadi
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Fractal Analysis ◽  
Fractal Geometry ◽  
Host Rock ◽  
Bouguer Anomaly ◽  
Research Area ◽  
Density Difference ◽  
Optimal Density

In exploration geophysics the main and initial aim is to determine density of under-research goals which have certain density difference with the host rock. Therefore, we state a method in this paper to determine the density of bouguer plate, the so-called variogram method based on fractal geometry. This method is based on minimizing surface roughness of bouguer anomaly. The fractal dimension of surface has been used as surface roughness of bouguer anomaly. Using this method, the optimal density of Charak area insouth of Hormozgan province can be determined which is 2/7 g/cfor the under-research area. This determined density has been used to correct and investigate its results about the isostasy of the studied area and results well-coincided with the geology of the area and dug exploratory holes in the text area

scholarly journals Geochemical response of deep geothermal processes in the Litang region, Western Sichuan

2018 ◽  
Vol 37 (2) ◽  
pp. 626-645
Author(s):  
Wei Zhang ◽  
Guiling Wang ◽  
Linxiao Xing ◽  
Tingxin Li ◽  
Jiayi Zhao
Keyword(s):  
Groundwater Recharge ◽  
Hot Springs ◽  
Cold Water ◽  
Isotope Analysis ◽  
Geothermal Field ◽  
Geothermal System ◽  
Calcite Dissolution ◽  
Western Sichuan ◽  
Geothermal Fields ◽  
Positive Correlations

The geochemical characteristics of geothermically heated water can reveal deep geothermal processes, leading to a better understanding of geothermal system genesis and providing guidance for improved development and utilization of such resources. Hydrochemical and hydrogen oxygen isotope analysis of two geothermal field (district) hot springs based on regional geothermal conditions revealed that the thermal water in the Litang region is primarily of the HCO3Na type. The positive correlations found between F−, Li2+, As+, and Cl− indicated a common origin, and the relatively high Na+ and metaboric acid concentrations suggested a relatively long groundwater recharge time and a slow flow rate. The values of δD and δ18O were well distributed along the local meteoric line, indicating a groundwater recharge essentially driven by precipitation. The thermal reservoir temperature (152°C–195°C) and thermal cycle depth (3156–4070 m) were calculated, and the cold water mixing ratio (60%–68%) was obtained using the silica-enthalpy model. Finally, hydrogeochemical pathway simulation was used to analyze the evolution of geothermal water in the region. The results were further supported by the high metasilicate content in the region. Of the geothermal fields in the region, it was found that the Kahui is primarily affected by albite, calcite precipitation, and silicate, while the Gezha field is primarily affected by calcite dissolution, dolomite precipitation, and silicate.

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