bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating shear wave velocity (Vs30) of East Java, Indonesia, using ambient noise inversion of horizontal to vertical spectral ratio (HVSR)
Authors: Tawakal M I , Haris A , Martha A A 
Published: July 2020

Abstract
The shear wave velocity on average to a depth of 30 m (Vs30) is an important parameter for seismic hazard assessment. Vs30 can identify soil dynamic characteristics that can be used to seismic hazards mitigation efforts. East Java is one of the provinces in Indonesia that has high geological disaster potential. Therefore, a study of earthquake risk mitigation strategies must be carried out as a disaster mitigation effort. One of the ways to determine soil characteristics is to estimate the shear wave velocity. This study aims to determine the average shear wave velocity (Vs30) to obtain information on the vulnerability of soil conditions in East Java. we use stationary seismograph data from Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG), German Research Centre for Geosciences (GFZ) temporary seismograph and secondary data from seismic waveform portable seismographs installed independently in East Java. This study uses the horizontal and vertical ambient noise inversion method. One-dimensional wave velocity models are obtained from Monte Carlo simulations based on the best misfit values. Vs30 East Java values ranged from 168–788 m/s with sediment thickness ranging from 10 meters to more than 200 meters. Based on the classification of soil types, in the northern part of East Java is dominated by the type of soft soil (SE) to hard soil (SC). In the southern part of eastern Java is dominated by medium soil (SD) to hard rock (SA). The northern part of East Java, especially in the Kendeng zone is dominated by low shear wave velocity. Lowest Vs30 can be seen in Sidoarjo, Surabaya, Mojokerto, Jombang, Gresik, Lamongan, Nganjuk, Madiun, Ngawi, Bojonegoro, Probolinggo and the southern part of the Madura Island. The low shear wave velocity (Vs30) is associated with sediment layers and high shear wave velocity (Vs30) is associated with hilly areas and transition zones.
Monitoring agroforestry for REDD+ implementation using remote sensing data and geographic information system: A case study of Repong Damar, Pesisir Barat Lampung
Authors: Laura C T , Darmawan A 
Published: July 2020

Abstract
Repong Damar is a unique practice of agroforestry found in Lampung that has a canopy structure nearly similar to that of natural forest. Apart from its uniqueness and important roles, effort to map and timely monitor the condition over Repong Damar is very limited. This research aims to analyze the most appropriate and accurate method for detecting Repong Damar using satellite images and to understand the historical change of Repong Damar cover. We tried to relate this effort to REDD+ potential implementation through agroforestry by estimating the forest reference level (FRL) of Repong Damar. Three methods of detection were used i.e. Object Oriented Classification (OOC), Maximum Likelihood Classification (MLC) and Vegetation Indices Classification (VIC). The most accurate method for detecting Repong Damar was the OOC. By using this method, time-series change of Repong Damar from 1990 to 2018 was determined. FRL was established by multiplying carbon stock of Repong Damar and the time-series average coverage area of Repong Damar from 1990 to 2015, i.e. 33,187,752 tC/yr. The emission performance of Repong Damar in 2018 was calculated from the total carbon stock of Repong Damar in 2018 against FRL. Repong Damar has emitted 1,485,378 tons of carbon in 2018.
Characteristics of primary tin mineralization in the Central and West Bangka Island
Authors: Aditya R , Setiawan I , Nugraheni R D , Sihombing F M H , Indra T L 
Published: July 2020

Abstract
Bangka Island is an important tin producer in Indonesia, mostly from the secondary tin deposits. However, the secondary tin deposit is depleting, causing further exploration shifted to the primary tin mineral. The purpose of this study is to make a mineralization model of primary tin deposit in Bangka Island. Methods that implemented in this study are petrographic analysis, mineragraphic analysis, XRD (X-Ray Diffraction), and XRF (X-Ray Fluorescence) analysis. The studied rock samples that consisted of granite, meta-sandstone, and sandstone. Some of the rocks are altered rocks with varying intensity. Petrographic and mineragraphic analysis show the presence of minerals that indicate the primary tin deposits, such as cassiterite, tourmaline, topaz, sericite, pyrite, and sphalerite. XRF analysis shows data about the value of Sn elements so that they can be classified into two classes, very high grade (> 800 ppm), and low grade (100–200 ppm). XRD analysis is necessary to do to determine the type and intensity of alterations that occur in the study area. The results of each analysis will provide supporting information regarding the primary tin mineralization process in Bangka Island.
Characteristics of surface hydrothermal alteration around Gunung Pancar area, West Java, Indonesia
Authors: Yoga D A , Sahdarani D N , Sihombing F M H , Grandis G , Supriyanto  , Kadja G T M 
Published: July 2020

Abstract
Hydrothermal alteration is an interaction between rock and hydrothermal fluid by means changing the mineralogical composition of the rock. This process is controlled by permeability, chemical composition, temperature, pressure, and duration of the hydrothermal alteration. Gunung Pancar, located in West Java, is considered an outflow for Gunung Gede Geothermal System. Typical geothermal surface manifestations found around Gunung Pancar are hot springs, warm ground and surface alteration. Basic geological mapping was conducted followed by water and altered rock sampling. Petrographic and diffraction methods are completed to confirm altered protolith. Water analyses were conducted to determine water type and origin. Alteration zonation is then inferred based on the water type, intensity of alteration and then cross referenced with indication of structural geological features. Zonation reveals that the intensity of alteration gets weaker as it moves away from the apparent faults. The result suggested that the permeability of the host rock affects thermal fluid movement around Gunung Pancar and subsequently the local geothermal conceptual model.
Identification of basement and subsurface structure of Depok City by using ESA-MWT gravity data
Authors: Hamonangan R A , Rosid M S 
Published: July 2020

Abstract
Basement is a hard layer which has a high-density contrast compare to the above it layer. In geotechnics, this layer is useful for the basement installation of high-rise buildings and other heavy buildings. Rock density contrast is sensitive physical parameter to be detected using gravity data. The study conducted in Depok City is aimed to identify the presence and the depth of the basement. Gravity data has been collected from 87 stations throughout the city of Depok. The average density value of rocks in the study area is 1.73 g/cc which was obtained by using the Parasnis method. The shallow basement layer is mapped using the Energy Spectrum Analysis - Multi Window Test (ESA-MWT) method. This method works by windowing test points from Complete Bouger Anomaly (CBA) values to get the interface depth for each test point. The fault structure can be identified through a residual anomaly map and by the Multi Scale - Second Vertical Derivative (MS-SVD) method whose results correlate with each other. The basement layer was successfully identified among the 3 other horizon layers and was at a depth of 0 - 68 m below the subsurface. Fault structures were also identified in the study area in the North and South part of the study area, where its fault identified as a normal fault.
A trend of surface solar radiation in Chiang Mai, Thailand
Authors: Promplin S , Charoentrakulpeeti W 
Published: July 2020

Abstract
The solar radiation passing through the atmosphere to the earth surface has varied in both increasing and decreasing directions. The decreasing direction caused mainly by aerosols, which its properties can absorb and reflect solar radiation. The emission sources of aerosol are primarily from human activities. This study aims to delineate a trend of surface solar radiation in Chiang Mai by using data from 7 air quality monitoring stations, recording during 1995–2017 in urban and rural areas. According to the Mann Kendal Sen’s Slope analysis, the results show that surface solar radiation in Chiang Mai has presented the decreasing trends in 5 stations which located in urban areas while the other 2 stations located in rural areas have presented increasing trends. This could be basically explained that the difference and intensity of activities between urban and rural areas has affected the variation of surface solar radiation.
Comparison of two rapid DNA extraction for DNA based identification from fish fillet products
Authors: Khoirunnisa V , Andayani N , Maryanto A E 
Published: July 2020

Abstract
Efficiency and quality on the result of DNA extraction determined the success of species identification using DNA. High concentration and good purity of DNA are the basic principle for choosing the appropriate extraction method. The objective of this research is to find an effective and efficient method from two different rapid DNA extractions, KAPA Express Extract Kit (KAPA Biosystem) and Chelex® 100 (Biorad). We used each method to extract 44 fish fillet samples from Jabotabek (Jakarta, Bogor, Tangerang, Bekasi) modern retail and traditional markets. We found the KAPA Express Extract Kit (KAPA Biosystem) had fast extraction time approximately 15 minutes for PCR-ready DNA faster than 20 minutes using the Chelex® 100 (Biorad) method. All the PCR-ready DNA are visualized with gel electrophoresis and both method resulted in positive DNA bands. We propose the use of KAPA Express Extract Kit (KAPA Biosystem) than the Chelex® 100 (Biorad) method because the fast and easily to use for the next analyses such as PCR and DNA sequencing.
A depositional setting variation and its effect to the coal quality of Warukin formation in Satui Area, South Kalimantan: Insight from maceral, biostratigraphy, electrofacies and lithofacies analyses
Authors: Haidiati F C , Sihombing F M H , Indra T L 
Published: July 2020

Abstract
Warukin Formation is one of the coal bearing formation in Kalimantan that has significant coal resource. The formation as Middle Miocene Age and deposited in generally regression stage. In addition to coal, it is composed of mudstone and sandstone with siderite nodule, with some coal seams also have parting of carbonaceous mudstone. Coal from Warukin has various quality that possibly related to the changes in depositional environment. This study attempted to understand the relation between depositional environment and the coal quality. To do that, coal is sampled from coal seams that can be found in study area. After collected, the sample then analyzed using lithofacies, electrofacies, biostratigraphy, and maceral analysis. These various analyses would uncover the slight variation on depositional setting between each seam in study area. Later, the result then correlated with the coal quality analyses that have been done before. From the study, it is concluded that some coal sample has higher Sulphur content that related with deposition with more seawater influence. Biostratigraphy analyses indicate that the interburden deposited in shallow marine setting, thus indicate that the depositional interchanged between transitional setting to shallow marine. Electrofacies also indicate that there were progradation and retrogradation process in the depositional activities. Maceral studies also indicate different type of maceral component that reflect the depositional variation within the seam.
Petrography characteristics of Quaternary volcanoes in Rawa Danau Caldera, Banten Province
Authors: Adani S , Indra T L , Syahputra R 
Published: July 2020

Abstract
The caldera from volcano eruptions often been found in Indonesia. However, the caldera which has swamp and lake such as Rawa Danau, Serang, Banten is rare in Indonesia. It encompasses with a swamp at the outer part and lake on the central part. The caldera surrounded by five Quaternary volcanoes, which are Mount Karang, Mount Parakasak, Mount Aseupan at the south, and Mount Tukung-Gede along with Mount Marikangen at the north side of the swamp. The Rawa Danau location is about 50 km to the East of Krakatau Volcano, so it might have been some linkage to its rock properties. This similarity can be seen from the textures and mineral compositions of their thin sections. Most of the volcano material resulted from different volcanoes. The challenging work was how to differentiate their sources eruption in the field because the weathering rate is high. Thus, this paper aims to differentiate the products of each young volcanoes in Rawa Danau using petrography analysis. In general, young volcanoes in Rawa Danau have trachytic and porphyritic textures, with plagioclase, pyroxene, and opaque as the phenocryst and microlite plagioclase as the matrix. The plagioclase can be found around 15–30 % as the phenocryst, microlite plagioclase as the matrix. The plagioclase type is around An55 compared with Krakatau which has An58. The magma characteristics of these young volcanoes might have a similarity with the magma of Krakatau Volcano.
Feasibility study of thermal anomaly detection for earthquake: A case study from 2014 Mae Lao earthquake, Thailand
Authors: Wongpornchai P , Suwanprasit C 
Published: July 2020

AbstractEarthquake is the natural disaster which causes damage to human lives and their properties, domestic animals and buildings in the areas near the epicentre. The ability to predict the earthquake can greatly reduce in catastrophic damages, but nowadays, earthquake prediction is still the unsolvable problem. However, the earthquake prediction is still an interesting topic for scientists all over the world. One of the important earthquakes precursors in earthquake preparatory phase is thermal anomaly. The thermal region data from remote sensing have been employed recently based on the concept of stress accumulation in the active plate tectonics region, which can be transformed as temperature variation prior event. Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) data have been commonly used to locate thermal anomalies prior to occurrence of earthquake event. In Thailand, 2014 Mae Lao Earthquake, the largest earthquake in the Thailand historical record with magnitude Mw 6.1, shook the area of Mae Lao District, Chiang Rai Province on 5thMay 2014. To locate possibility of thermal anomalies, the daily data of MODIS MYD11A1 product for 30 days before and after the earthquake were processed and analysed. Average LST before and after earthquake events were used for removing background temperature in the area and comparative method was performed to detect the thermal anomalies. The result found that this simple technique detected the thermal anomaly occurrence during 12-23 days prior to the earthquake and 9-28 days after the earthquake. Nevertheless, in order to understand furthermore about earthquake mechanism, it is necessity of discovered thermal precursors.
Estimation of reservoir lithology in field “A” using modeling of anisotropy parameter
Authors: Ramadhan M F F , Rosid M S , Purba H 
Published: July 2020

Abstract
The heterogeneity and anisotropy of rocks in the field is a necessity. Moreover, the existence of clay and carbonate sediment in Indonesia almost dominate the existing oil and gas reservoir. Ironically, the processing of seismic data is still much done by treating reservoir rocks as an isotropic homogeneous medium. Inaccuracies of results, therefore, always haunt the failure of exploration. Hockey stick phenomenon is the result of anisotropic medium that often appears on the far offset. Demand for the implementation of an anisotropic rock medium is now increasing and more important amid the exhaustive oil and gas reserves. NMO correction by using hyperbolic travel time on anisotropic media still displays the phenomenon of hockey stick at the remote offset. Usually this phenomenon will be muted on the processing of seismic data with the approach of isotropic earth models. This will result in the loss of some lithologic information. Therefore, this study was conducted using anisotropic approach to reduce residual moveout for data which has a very long offset. The method is to calculate the anisotropy parameter model of η which is controlled by core data. The results of this study showed that the Alkhalifah and Tsvankin method of non-hyperbolic travel time was better in the NMO correction for anisotropy medium with a long offset compared to the method of hyperbolic travel time. In addition, Alkhalifah and Tsvankin method can also estimate the lithology of a reservoir. The value of anisotropy parameter η from the equation itself has the same pattern as the gamma ray log. In reservoir, the sand has negative η value and shale has positive η value.
Variation on the coastal deposit in Nusa Tenggara Islands based on the mineralogy and petrographic analysis
Authors: Savira D , Sihombing F M H , Indra T L 
Published: July 2020

Abstract
Sand as part of sedimentary material can be consisted of single mineral fragments, rock fragments, or even biogenic materials. Nusa Tenggara is an archipelago that was formed due to the meeting of the Indian Ocean Plate and the Eurasian Plate which supported by other geological processes. The stratigraphy of these islands is dominated by carbonate rocks, volcanic rocks, coastal deposits and alluvium. Due to the variation of the rock composition, there is a large possibility that mineralogy sediment material found in the coastal area will be different from one place to other. This study aims to analyse variations on coastal deposits in a number of specific locations in the Nusa Tenggara Islands. This study was carried out by mineralogical and petrographic analysis of sand samples from six coastal areas in Nusa Tenggara Islands. The mineral composition of coastal sand was identified using hand loupe to give general understanding. After that, the petrographic analyses were implemented to give detailed mineralogical analyses of each sand. Mineralogical studies are specialized in study of the physical structure and chemical composition of each mineral, while petrographic studies can support the details of every physical information obtained through macroscopic observations. Data are retrieved by taking sand samples directly in the research field in a certain amount. This sample is separated then for macroscopic analysis while the other parts are made in a thin section. The thin section will be used for petrographic analysis under a polarization microscope. The analysis result shows that there are variations in coastal sediment components and it most likely does to different rock found around such area.
3D broadband seismic inversion: Case study of exploration cretaceous sandstone, North Arafura Basin
Authors: Sofyadi A , Haris A , Riyanto A , Sutha I M 
Published: July 2020

Abstract
This paper presents applications of Absolute and Relative Acoustic Impedance of seismic inversion for qualitative and quantitative seismic interpretation from 3D Broadband PSDM Post-stack Seismic data. A case study from the exploration area of Late Cretaceous – Early Cretaceous Clastics in Arafura Sea, eastern Indonesia has been perform in this work, where inside the study area have no well information for seismic inversion at all. The present work shows the promising contribution of applying 3D Broadband Seismic Velocity for background trend of 3D Post-Stack Model Based Seismic Inversion and perform interpretation from 3D Broadband Relative Acoustic Impedance to reduce the uncertainty associated with the seismic interpretation, to recognize the porous sand section (as an indication of hydrocarbon reservoirs) and to understand the distribution of the reservoir based on seismic data-driven, to later for define the high certainty location of exploration well.
Identification of geological structures by using ESA-MWT and MS-HDVD gravity data at Slawi, Central Java
Authors: Rosid M S , Christanto M 
Published: July 2020

Abstract
It has been done of a geophysical measurement by Pertamina in the Slawi area of Central Java. The results of the seismic section show that there is an up dome in the field “M”. The location of this area is in the mt. Slamet zone. So that the existence of an up-dome structure does not automatically provide the possibility of a hydrocarbon trap in the area. This study was conducted to characterize the existence of these structures using gravity data. The ESA-MWT (energy spectral analysis multi window test) and MS-HDVD (multi scale-horizontal derivative vertical derivative) methods of gravity data are applied in this study. The ESA-MWT method is able to map lateral rock variations very well, whereas MS-HDVD is more sensitive to vertical variations even though it is also good for identifying rock variations in both vertically and laterally. There are five horizons detected in the field. These five interfaces with density contrast extend over a depth range between 416 to 2112 meters. The horizons are identified as being associated with sediment rocks namely Formations of Tapak, Penosogan, Kumbang, Halang and Rambatan. The sediments are likely to be intruded by diorite stones (in up-dome form) which happened during the Late Miocene. The peak, or top, of the intrusion body is estimated at around 620 to 755 m depth on the Penosogan Formation.
Geostatistics analysis as a tool to create the distribution model of Rawa Danau volcano deposits, Banten Province
Authors: Mulyo M J W , Syahputra R , Indra T L 
Published: July 2020

Abstract
The eruption of an ancient volcano at the early Pleistocene had deposited volcanic material evenly, especially in the western part of Rawa Danau. Many smaller mountains emerged around Rawa Danau volcano as the Pleistocene volcano erupted. Then, at the end of the Pleistocene, the ancient volcano erupted for the second time with a very large force that destroyed most of the mountain and created a caldera. The volcanic material from the second eruption was distributed to evenly around the ancient volcano. We used geostatistical analysis with Inverse Distance Weighted (IDW) method to interpolate the spreading of volcanic deposits both in the first and second eruption. The objective of this research is to predict the volcanic deposits in the area which has not been researched yet and it is possible to have more eruptions in the future since geothermal manifestations such as hot springs are found in the research area. We used the outcrop data from geological mapping to interpolate the data. The output of this paper would be the interpolation map of facies deposits in Rawa Danau.