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.    

scholarly journals Geothermal Systems Characteristics in Pesanggrahan Area, Bawang Distric, Batang Regency, Based on Geology and Geochemistry Analysis

2019 ◽  
Vol 125 ◽  
pp. 14002
Author(s):  
Rakhmadi Sulistyanto ◽  
Udi Harmoko ◽  
Gatot Yuliyanto
Keyword(s):  
Hot Springs ◽  
Hot Spring ◽  
Descriptive Analysis ◽  
Hot Water ◽  
Geothermal System ◽  
Water Type ◽  
Geothermal Systems ◽  
Volcanic System ◽  
Geothermal Fluid ◽  
Chloride Water

Research conducted at Pesanggrahan area, Sangubanyu Village, Bawang District, Batang Regency with geographical coordinates at 7°5'00 "00 S - 7°7'30" 00 S, and 109 ° 56'00 "E-109°58'30"E, with an area of around 25 Km². Research methods used quantitative and qualitative methods with descriptive analysis, geological and geochemical analysis. Geochemical fluid samples were taken in manifestations hot springs Pesanggrahan and hot water samples in Sibanteng and Sileri Crater to determine the relationship with geothermal systems in this area. Geomorphology divided into two geomorphology units, they are steep slope and sloping hill. Stratigraphy can be divided into three lithologies, which are andesite breccia, tuff breccia, and tuff sandstone. Based on fluid geochemical characteristics of manifestations, it can be interpreted that hot spring of Pesanggrahan area is outflow zone with bicarbonate-chloride water type, Sibanteng Crater and Sileri Crater, include upflow zone with water type sulfate for Sibanteng Crater, bicarbonate-sulfide water type for Sileri Crater. Environmental source geothermal fluid Pesanggrahan from the magmatic volcanic process. Sources geothermal fluid in Pesanggrahan, Sibanteng and Sileri Crater from meteoric water. Estimated temperature Pesanggrahan in the interval 50-100°C, Sileri Craters 160-180°C, and Sibanteng Craters 140-150°C. The Conceptual model of Pesanggrahan includes a geothermal system that associated with volcanic system and high relief liquid dominated system.

scholarly journals 2D Forward Modeling Geothermal System Gravity Data in South Solok Region, West Sumatra

2021 ◽  
Vol 4 (1) ◽  
pp. 36-44
Author(s):  
Muhammad Nafian ◽  
Belista Gunawan ◽  
Nanda Ridki Permana
Keyword(s):  
Heat Source ◽  
Geothermal Energy ◽  
Gravity Data ◽  
Bouguer Anomaly ◽  
Filter Method ◽  
Geothermal System ◽  
Geothermal Systems ◽  
West Sumatra ◽  
Anomaly Map ◽  
Bouguer Anomaly Map

Indonesia has the greatest potential for geothermal energy in the world. Geothermal has an important role as an alternative fuel because it is a renewable energy source, but its use has not been maximized. One of the areas that have the greatest potential for geothermal energy in South Solok, West Sumatra. Therefore, this study was conducted to determine the geothermal system in the South Solok area, West Sumatra by using the gravity method. The gravity data processing stage requires some software to get the CBA value(Complete Bouguer Anomaly), map contours of the CBA. Anomaly separation with the butterworth filter method, determination of residual anomaly slice points, and 2D modeling of geothermal systems. Based on modeling, the qualitative interpretation interprets the Complete Bouguer Anomaly map which is suspected as a geothermal prospect area is a low anomaly ranging from 7.9 mgal - 9.4 mgal which is marked in dark blue. Meanwhile, quantitative interpretation produces modeling of the AB and CD slicing with a total of four layers. This layer consists of clay rock as a cap rock, sandstone as a reservoir, granite as a heated rock as a heat source, and the last layer in the form of magma as a heat source. The anomaly modeling of these two sections is dominated by granite rock with a density value of 2500 kg/m3 for the AB section and 2550 kg/m3 for the CD section.

scholarly journals Natural State Modeling of Singapore Geothermal Reservoir

2012 ◽  
Vol 3 ◽  
pp. 34-40
Author(s):  
Hendrik Tjiawi ◽  
Andrew C. Palmer ◽  
Grahame J. H. Oliver
Keyword(s):  
Hot Springs ◽  
Hot Spring ◽  
High Heat ◽  
Hot Water ◽  
Geothermal Reservoir ◽  
Natural State ◽  
Geothermal System ◽  
Fuel Price ◽  
The Cost ◽  
Engineered Geothermal System

 The existence of hot springs coupled with the apparent anomalous high heat flow has sparked interest in the potential for geothermal development in Singapore. This geothermal resource may be potentially significant and could be exploited through Engineered Geothermal System (EGS) technology, i.e. a method to create artificial permeability at depth in granitic or sandstone formations as found under Singapore. The apparently ever-increasing fossil fuel price has made the cost of using the EGS technology more viable than it was in the past. Thus, to assess the resource, a numerical model for the geothermal reservoir has been constructed. Mass and heat flows in the system are simulated in 2D with AUTOUGH2.2, and the graphical interface processed through MULGRAPH2.2. Natural state calibration was performed to match both the observed and the expected groundwater profile, and also to match the hot water upflow at the Sembawang hot spring, with simulated flowrate matching the hot spring natural flowrate. The simulation gives an encouraging result of 125 - 150 °C hot water at depth 1.25 – 2.75 km.

INTERPRETASI BAWAH PERMUKAAN GUNUNG ANAK RANAKAH DENGAN PEMODELAN DUA DIMENSI (2D) BERDASARKAN DATA ANOMALI GRAVITASI LOKAL

2018 ◽  
Vol 3 (1) ◽  
pp. 54-58
Author(s):  
Godensius Tematur ◽  
Jehunias L. Tanesib ◽  
Redi K. Pingak
Keyword(s):  
Continuation Method ◽  
Atmospheric Correction ◽  
Bouguer Anomaly ◽  
Geophysical Research ◽  
Subsurface Geology ◽  
Dimensional Modeling ◽  
Free Air ◽  
Geological Conditions ◽  
Free Air Anomaly ◽  
Surrounding Areas

ABSTRAK Penelitian geofisika dengan menggunakan metode gravitasi telah dilakukan di Gunung Anak Ranakah dan sekitarnya di kabupaten Manggarai Nusa Tenggara Timur pada bulan Juni sampai dengan bulan Juli 2016. Penelitian ini bertujuan untuk mengetahui kondisi geologi bawah permukaan daerah penelitian dengan menggunakan data anomali udara bebas dari Sandwell dan Smith 2016. Data tersebut direduksi dengan koreksi atmosfer, koreksi Bouguer Sederhana, dan koreksi kurvatur hingga memperoleh anomali Bouguer Lengkap. Data anomali Bouguer dibawa ke bawah bidang topografi dengan metode kontinuasi ke bawah sedalam 300 m menggunakan program Magpic. Selanjutnya dilakukan pemodelan 2 dimensi menggunakan program Grav2DC. Hasil yang diperoleh menunjukkan bahwa kondisi geologi bawah permukaan gunung Anak Ranakah dan Sekitarnya didominasi oleh batuan basalt (densitas 2,70 -3.30 ), andesit (densitas 2.4 -2.8 ), dan soil (densitas 1.2 -2.40 ). Kata kunci: Anomali Gravitasi, Pemodelan 2D, Gunung Anak Ranakah ABSTRACT Geophysical research by using the gravity method has been carried out on the Ranakah child mountain and surrounding areas in Manggarai Regency of East Nusa Tenggara in June until July 2016. This research aims to know the condition of the subsurface geology of the area of research using the free air anomaly data from Sandwell and Smith 2016. The data are reduced by atmospheric correction, Simple Bouguer correction, and the correction of curvature to obtain complete Bouguer anomalies. Bouguer anomaly data brought down the field topography with continuation method down as deep as 300 m using the Magpic. Then, 2 dimensional modeling is done using the Grav2DC. The results obtained show that the geological conditions under the surface of the Ranakah Child mountaoin and its surrounding area was dominated by basalt rocks (density of ), andesite (density of ), and soil rocks (density of ). Keywords: Gravity Anomaly, 2D Modelling, Ranakah child Mountain.

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 Analisa Geoelectrical Strike Metode AMT untuk Identifikasi Awal Potensi Sistem Panas Bumi di Daerah Gunung Pancar Bogor Jawa Barat

2019 ◽  
Vol 3 (1) ◽  
pp. 23
Author(s):  
Wahyu Hidayat ◽  
Hafiz Hamdalah ◽  
Hana Aulia K
Keyword(s):  
Sedimentary Rock ◽  
Hot Springs ◽  
Geological Structure ◽  
Discharge Zone ◽  
Geothermal System ◽  
Geothermal Systems ◽  
Font Size ◽  
1D Modeling ◽  
Magnetotelluric Method ◽  
Modeling Data

<p><span style="font-size: medium;">Satu daerah yang diduga terdapat sistem panasbumi adalah daerah Gunung Pancar, Bogor, Jawa Barat.<em> </em>Beberapa mata air panas yang muncul di sekitar daerah penelitian memperkuat dugaan adanya sistem panasbumi di daerah tersebut<em>.</em> Metode geofisika yang dapat digunakan untuk mengidentifikasi sistem panasbumi adalah Metode Audio Magnetotelurik (AMT). Penelitian ini menggunakan metode AMT untuk mendapatkan gambaran bawah permukaan dengan pemodelan 1D dan pemodelan 2D. Pengolahan data dilakukan dengan menggunakan <em>software</em> MT Editor, Interpex, dan Petrel. <em>Geoelectrical</em> <em>strike</em> digunakan untuk mengetahui arah <em>strike</em> bawah permukaan dimana nilai kontras resistivitasnya dapat diindikasikan sebagai gangguan geologi. Data yang digunakan adalah data <em>angle</em> dan <em>radius</em> pada <em>software</em> MT Editor. Sementara <em>software</em> yang digunakan untuk membuat diagram roset adalah <em>software</em> GeoRose. Hasil pemodelan menunjukkan adanya komponen panasbumi berupa <em>claycap </em>(1 Ω.m – 10 Ω.m) dan <em>reservoir </em>(10 Ω.m – 20 Ω.m) pada kedalaman 300 m hingga 2000 m. Lapisan <em>young sedimentary rock </em>diinterpretasikan sebagai zona aliran air panas dengan nilai tahanan jenis sebesar 10 Ω.m – 100 Ω.m. Sistem panasbumi di daerah penelitian diduga dikontrol oleh struktur geologi berupa sesar mendatar, antiklin, dan sinklin yang berkembang di bagian timurlaut daerah penelitian. </span></p><p><em style="font-size: medium;">T</em><em style="font-size: medium;">he areas that possibly had geothermal system is Mount Pancar, Bogor, West Java. There are several hot springs found around the study area. The geophysical method that can be used to identify the geothermal system and geological structure is the Audio-Magnetotelluric Method (AMT). AMT method is used to obtain subsurface overview with 1D modeling and 2D modeling. Data processing is done by using MT Editor, Interpex, and Petrel software. Geoelectrical strike is used to determine the direction of the subsurface strike by resistivity value. The most dominant angle and radius data from software MT Editor is used to make rosette diagram to show the geoelectrical strike. The results of 1D modeling showed the geothermal component such as claycap (1 Ω.m - 10 Ω.m) and reservoir (10 Ω.m - 20 Ω.m) at a depth of 300 m to 2000 m. The young sedimentary rock layer is interpreted as a discharge zone with a resistance value of 10 Ω.m - 100 Ω.m. The geothermal systems in the study area might be controlled by geological structures in the northeast of the study area.</em></p>

scholarly journals 3D Modeling of Subsurface Lawanopo Fault In Southeast Sulawesi, Indonesia Using Grablox and its Consequence to Geohazard

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Triani Triani ◽  
Rofiqul Umam ◽  
Sismanto Sismanto
Keyword(s):  
3D Modeling ◽  
Continuation Method ◽  
Bouguer Anomaly ◽  
Three Dimensional ◽  
Strike Slip ◽  
Horizontal Shear ◽  
Rock Structure ◽  
Value Decomposition ◽  
Processing Techniques ◽  
Occam Inversion

Lawanopo Fault is a horizontal shear fault (sinistral strike-slip) found in Southeast Sulawesi province and is thought to be active during Plio-Pleistocene or mid-late Miocene to the present. This study has been carried out which aims to find out the geometric shapes below the surface of the Lawanopo fault using complete Bouguer anomaly (ABL) data.  The ABL data is projected onto a flat plane using the Dampney method at an altitude of 8 km, and the separation of local and regional anomalies is carried out using the upward continuation method at an altitude of 60 km. Three-dimensional (3D) modeling under the surface of the Lawanopo fault is done using the computer program Grablox. Data processing techniques using Singular Value Decomposition (SVD) and Occam inversion. The results showed that a high gravity anomaly of 190-225 mGal was caused by an igneous rock below the surface with a density of 2.7-3.33 gr/cm3 and a thickness of about 13 km, a moderate anomaly of 175-187 mGal caused by Paleozoic igneous rocks aged Carbon with a density of 2.6-2.9 gr/cm3 and a thickness of about 25 km. Low anomaly 115-160 mGal is caused by rocks with a density of 2.0-2.5 gr/cm3 and a thickness of about 22-23 km. The Lawanopo fault constituent rocks consist of alkaline rocks in the basement covered by sediment and metamorphic with a depth of Lawanopo fault more than 15 km and begin to be seen at a depth of 4.3 km of the surface. it is known that the area around the Lawanopo fault is an area prone to earthquakes. But, based on the soil and rock structure around the Lawanopo fault, the compactness and attenuation levels in reducing earthquake waves are quite good, so that land use around the Lawanopo fault tends to be safe.

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>

Exploration of orogenic, fault-hosted geothermal systems using an integrated, multi-disciplinary approach.

2021 ◽  
Author(s):  
Carbajal-Martínez Daniel ◽  
Loïc Peiffer ◽  
Larryn W. Diamond ◽  
John M. Fletcher ◽  
Claudio Inguaggiato ◽  
...  
Keyword(s):  
Meteoric Water ◽  
Hot Springs ◽  
Water Discharge ◽  
Fault System ◽  
Geothermal System ◽  
Heat Output ◽  
Geothermal Systems ◽  
Isotopic Analyses ◽  
Agua Blanca Fault ◽  
La Jolla

&lt;p&gt;Non-magmatic, orogenic geothermal systems are recognized as significant energy resources for electricity production or direct uses. This study focuses on the non-magmatic geothermal system hosted by the Agua Blanca fault, Ensenada, Mexico. The Agua Blanca fault is a 140 km long transtensional structure with segments recording up to 11 km of dextral strike-slip displacement and normal throws of up to 0.65 km. We have identified at least seven geothermal areas manifested by hot springs discharging at temperatures ranging from 38 &amp;#176;C to 107 &amp;#176;C. These systems involve topography-driven infiltration of meteoric water deep into the Agua Blanca fault and exfiltration of the heated water at valley floors and along a local beach known as La Jolla.&lt;/p&gt;&lt;p&gt;For this contribution, we present recent and ongoing exploration activities aiming to (i) obtain a fundamental understanding of the governing thermal-hydraulic-chemical processes controlling the circulation of meteoric water in the hydrothermally active fault system and (ii) quantify the natural discharge rate and its respective advective heat output. Chemical and isotopic analyses of thermal springs and seismic epicenters' location reveal that meteoric water penetrates between 5 to 10 km deep into the brittle orogenic crystalline basement and thereby attains temperatures between 105 and 215 &amp;#176;C. Interestingly, the deepest circulation and hottest reservoir temperatures occur where the extensional displacement along the fault shows maximum values. However, our data provide no evidence that meteoric water infiltrates beyond the brittle-ductile zone in the crust (12-18 km).&lt;/p&gt;&lt;p&gt;For the La Jolla beach thermal area, we have quantified the advective heat output from thermal images acquired with an unmanned aerial vehicle equipped with a thermal camera and from water flow and direct temperature measurements. The total thermal water discharge is 330 &amp;#177; 44 L s&lt;sup&gt;-1&lt;/sup&gt; and occurs over a surface area of 2804 m&lt;sup&gt;2&lt;/sup&gt; at temperatures up to 52 &amp;#176;C. At 20 cm depth, the temperature is as high as 93 &amp;#176;C. These observations collectively imply a current heat output of 40.5 &amp;#177; 5.2 MW&lt;sub&gt;t &lt;/sub&gt;(Carbajal-Mart&amp;#237;nez et al., 2020). We are currently estimating the shape and magnitude of the subsurface thermal anomaly at La Jolla beach by performing coupled thermal-hydraulic-chemical simulations using the code Toughreact.&lt;/p&gt;&lt;p&gt;We conclude that meteoric water circulation through the Agua Blanca fault system reflects the interplay between the permeability distribution along the fault system and the rugged regional topography. Under ideal conditions such as at La Jolla beach, such circulation generates rather large thermal outputs that could supply the thermal energy for a multi-effect distillation desalinization plant and contribute to cover the shortage of fresh water in Ensenada.&lt;/p&gt;

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