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Denney, Dennis. "Hybrid Gas-Lift Application Offshore Northwest Java." Journal of Petroleum Technology 52, no. 05 (2000): 30. http://dx.doi.org/10.2118/0500-0030-jpt.
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Sutayasa, Md. "Notes on the Bum Pottery Complex, Northwest Java." Mankind 8, no. 3 (2009): 182–84. http://dx.doi.org/10.1111/j.1835-9310.1972.tb00433.x.
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Septama, Erlangga, C. Prasetyadi, A. Abdurrokhim, et al. "The hidden sedimentary basin underneath the Quaternary volcanic unit in Bogor and Kendeng area." Berita Sedimentologi 47, no. 2 (2021): 25–47. http://dx.doi.org/10.51835/bsed.2021.47.2.323.
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The Java Island is an active volcanic arc that experiences several volcanism episodes, which gradually changes from South to North from the Late Oligocene to Pleistocene, following the subduction of the Australian plates underneath the Eurasian plates. During the Eocene, the southern and northern part of Java was connected as one passive margin system with the sediment supply mainly comes from Sundaland in the north. The compressional tectonics creates a flexural margin and a deep depression in the central axis of Java Island and acts as an ultimate deep-sea depocenter in the Neogene period. In contrast to the neighboring Northwest and Northeast Java Basins in the Northern edges of Java Island, the basin configuration in the East-West trending depression in median ranges of Java (from Bogor to Kendeng Troughs) are visually undetected by seismic due to the immense Quaternary volcanic eruption covers.Five focused window areas are selected for this study. A total of 1,893 Km sections, 584 rock samples, 1569 gravity and magnetic data, and 29 geochemical samples (rocks, oil, and gas samples) were acquired during the study. Geological fieldwork was focused on the stratigraphic unit composition and the observable features of deformation products from the outcrops. Due to the Paleogene deposit exposure scarcity in the Central-East Java area, the rock samples were also collected from the mud volcano ejected materials in the Sangiran Dome.The distinct subsurface configuration differences between Bogor and Kendeng Troughs are mainly in the tectonic basement involvement and the effect of the shortening on the formerly rift basin. Both Bogor and Kendeng Troughs are active petroleum systems that generate type II /III Kerogen typical of reduction zone organic material derived from transition to the shallow marine environment. The result suggests that these basins are secular from the neighboring basins with a native petroleum system specific to the palaeogeographical condition during the Paleogene to Neogene periods where the North Java systems (e.g., Northwest and Northeast Java Basin) was characterized by oxidized terrigenous type III Kerogen.
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Widianto, E. "Petroleum system of Northwest Java basin based on gravity data analysis." IOP Conference Series: Earth and Environmental Science 106 (January 2018): 012106. http://dx.doi.org/10.1088/1755-1315/106/1/012106.
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Namara, Aliep Fishabil, I. Wayan Nurjaya, and Mochamad Tri Hartanto. "Modelling of ocean currents and distribution of total suspended solids in Citarum River estuary." BIO Web of Conferences 106 (2024): 03004. http://dx.doi.org/10.1051/bioconf/202410603004.
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The Citarum River is an important river in West Java, which empties into the Java Sea carrying large suspended sediment concentrations. The purpose of this study is to examine the interaction of current patterns and distribution of total suspended solids (TSS) in the Northwest and Southeast Monsoons using hydrodynamic Modelling. The flow model and TSS used were 2-dimensional models with the OpenFlows FLOOD software. The ocean tide model results were validated using the Root Mean Square Error (RMSE) method with a value of 0.10. The current velocity in the West and East monsoons ranges from 0.07 - 0.35 m/s. Currents flow north and northeast during high-tide conditions and move south and southwest during low-tide conditions in both seasons. The movement of TSS was influenced by the current patterns. The highest concentration of TSS is in the Northwest Monsoon at low tide, which was in the range of 560–575 mg/L. The lowest TSS concentration was in the Southeast Monsoon during high tide conditions, ranging from 80 to 120 mg/L. The high concentration of TSS in the Northwest Monsoon was influenced by higher rainfall, with an average in January and only 23.2 mm/day while in the Southeast Monsoon it is only 7.8 mm/day.
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Adriansyah and George A. McMechan. "AVA analysis and interpretation of a carbonate reservoir: northwest Java basin, Indonesia." GEOPHYSICS 66, no. 3 (2001): 744–54. http://dx.doi.org/10.1190/1.1444964.
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A detailed analysis is performed of amplitude variation with angle (AVA) observations in six common‐midpoint gathers with reflection points that are over and beside carbonate reefs in the Parigi Formation in the northwest Java basin. Both empirical analysis and full‐wavefield modeling of the AVA data suggest that the presence of gas affects AVA by reducing the bulk density of the reservoir, decreasing of the overburden [Formula: see text] ratio and by local attenuation caused by gas sieving through the overlying sediments. The slopes of AVA curves for reflections from the top of the Parigi are negative for brine saturation and strongly positive for gas saturation.
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Hidayati, Sri, Y. Suparman, and A. Loeqman. "Focal Mechanism and Parameter of Volcano-Tectonic Earthquake Source, in Mount Guntur, West Java." Indonesian Journal on Geoscience 6, no. 1 (2011): 1–11. http://dx.doi.org/10.17014/ijog.6.1.1-11.
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DOI: 10.17014/ijog.v6i1.111Guntur Volcano in West Java is one of the most active volcanoes in Indonesia. The last eruption took place in 1847 and the volcanic activity has been dormant since then, however its seismicity is active. During the period of July to October 2009, the hypocenter distribution of VT earthquakes is mostly located at western flank of the volcano, beneath Guntur - Gandapura craters at the depth of less than 5 km. The depth pattern shows deeper to the northwest. The VT earthquakes deeper than 5 km were not found in this period. The focal mechanism of VT earthquakes are oblique normal fault, strike-slip fault and oblique reverse fault types. The mechanism of those earthquakes is not uniquely determined probably due to complicated structures at Guntur volcano complex area, which is aligned in NW-SE direction. T-axis of the oblique normal fault is trending in northwest - southeast direction similar to the structures found in the summit area of Gunung Guntur Volcano. Similarly, one of the strike-slip fault nodal line and P-axis of oblique reverse fault are also trending in northwest - southeast. Ploting of the earthquake source parameters (seismic moment, corner frequency, and stress drop) made to hypocenter distance shows no significant difference on those parameters between earthquakes at close and far distances to Kabuyutan station. It is probably due to the hypocenters are not concentrated in one zone. Meanwhile, the relationship between seismic moment (Mo) and seismic source radius (r) shows that for earthquakes with moment of smaller than 1018 dyne cm, the radius of the hypocenter is constant which is namely 60 m.
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Napitupulu, Haposan, Leroy Ellis, and Richard M. Mitterer. "Post-generative alteration effects on petroleum in the onshore Northwest Java Basin, Indonesia." Organic Geochemistry 31, no. 4 (2000): 295–315. http://dx.doi.org/10.1016/s0146-6380(99)00154-0.
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Adriansyah, A., and George A. McMechan. "Analysis and interpretation of seismic data from thin reservoirs: Northwest Java Basin, Indonesia." GEOPHYSICS 67, no. 1 (2002): 14–26. http://dx.doi.org/10.1190/1.1451317.
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A detailed analysis and interpretation is performed of a 2‐D seismic line over a sequence of thin reservoirs in the upper Cibulakan formation in the Northwest Java Basin. Most well sites in this area are selected to be structures near fault zones as faults are assumed to be the main hydrocarbon migration paths. Amplitude variation with offset analysis is little used because of contamination by thin‐layer tuning effects. Attribute analysis, impedance inversion, and full‐wavefield modeling suggest that gas reservoirs are detectable even when they are less than their tuning thickness, as they correspond to acoustic impedance anomalies and low instantaneous frequency. The presence of hydrocarbons can also be detected by anomalous behavior in crossplots of acoustic impedance versus density and P‐wave velocity; sandstone reservoirs show low velocity and low impedance. Two‐dimensional P‐velocity and density distributions resulting from impedance inversion produce synthetic elastic common‐source gathers that display reflection behaviors that are qualitatively similar to the corresponding field data.
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Tri Muji Susantoro, Sugihardjo, Ketut Wikantika, et al. "CCUS-EOR Optimization to Achieve Zero Emission Program Targets in Northwest Java Basin." Evergreen 10, no. 3 (2023): 1809–18. http://dx.doi.org/10.5109/7151730.
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Pratama, Cecep, Leni Sophia Heliani, Nurrohmat Widjajanti, et al. "Recent GPS-based long wavelength crustal deformation revealed active postseismic deformation due to the 2006 Yogyakarta earthquake." Journal of Applied Geodesy 16, no. 2 (2022): 131–41. http://dx.doi.org/10.1515/jag-2020-0053.
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Abstract We analyze the Global Positioning System (GPS)-derived strain rate distribution to investigate active crustal structure in Central Java, Indonesia, using ten years (2010–2019) continuous and permanent observation data. Central Java is the third-most populous province in Indonesia where postseismic deformation of devastating Yogyakarta earthquake in 2006 might influence the GPS data. The postseismic extensional response might overshadow the low contractional process due to active tectonics deformation. A decomposition method of a calculated strain rate shows a long wavelength feature with the extensional region in the vicinity of the 2006 Yogyakarta earthquake may reflect the postseismic process remain active. The short wavelength pattern is sharpening potential active tectonics dominated by oblique Northwest-Southeast dip-slip motion with East-West left-lateral sense. Our result demonstrates essential implications for assessing future seismic hazard potential within a low strain rate such as the Central Java region.
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Suwondo, Suwondo, Mill Sartika Indah, Afzalurrahman Assalam, Muhammad Nafian, and Andika Perbawa. "Lithofacies Interpretation Of Sediment Rocks In The Cipamingkis River Outcrop, Jonggol Area, Bogor District, West Java." Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics 6, no. I (2023): 60–70. http://dx.doi.org/10.15408/fiziya.v6ii.34282.
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This research aims to study sedimentary structures and determine the depositional environment of the outcrop in the Cipamingkis River, Jonggol area, Bogor Regency, West Java. The method in this study includes literature studies, field surveys, data interpretation, and facies analysis. The result shows the outcrop in the Cimangkis River can be divided into four (4) sedimentation sequences unit: Claystone Unit (Sequence 1), Limestone/Calsirudit Unit (Sequence 2), Limestone/calcarenite-Calcilutite Unit (Sequence 3), Mudstone/ Calsilutite Unit (Sequence 4). Based on the depositional environment analysis, this outcrop displays characteristics of a shallow marine environment. The Interpretation of facies from outcrops can be used as a reservoir analog and can support subsurface interpretation in the Northwest Java Basin
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Tejakusuma, Iwan Gunawan. "SOIL CREEP IN BALEKAMBANG, CIRAWAMEKAR, CIPATAT DISTRICT, BANDUNG BARAT REGENCY, WEST JAVA." Jurnal Sains dan Teknologi Mitigasi Bencana 13, no. 2 (2019): 96. http://dx.doi.org/10.29122/jstmb.v13i2.3369.
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Soil creep occurred in Balekambang, Cirawamekar, Cipatat, West Bandung Regency, West Java. This area is karst hill consist of limestone with interbedded sediment in the valley. The limestone is interfingered with clay, marl and quartz sandstones. The clay and marl acting as the slipping plane with a steep dip of around 50o to 69o to the northwest. The direction of the slope movement approximately follows the direction of the bedding plane therefore the bedding plane control the soil creep. This landslide was triggered by rainfall which saturated the soil layer and environmental changes in the surrounding area.
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Lelono, Eko Budi. "Oligocene Palynology Of On-Shore West Java." Scientific Contributions Oil and Gas 35, no. 2 (2022): 67–82. http://dx.doi.org/10.29017/scog.35.2.779.
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Compared to its counterpart in the off-shore area (including Northwest Java and Northeast Java), the Oligocene sediment of on-shore West Java provides low pollen assemblages. In addition, superwet elements of Dacrydium and Casuarina commonly occurred in off-shore area are less represented in the on-shore area. However, it is believed that the study area still experienced wet climate condition as proved by common occurrence of rattan pollen Dicolpopollis spp. indicating a thick growth of swamp forest under moist climate. Unlike its counterpart in the off-shore North West Java, the studied sediment rarely yields lacustrine elements suggesting the disappearance of lake deposit. The Oligocene sediment of on-shore West Java is defi ned by the regular appearance of Oligocene marker of pollen Meyeripollis naharkotensis. The last occurrence of this pollen marks the top Oligocene age. In fact, the appearance of pollen M. Naharkotensis is obviously used to separate Oligocene age from Miocene age in the off-shore area. Moreover, marine micropaleontology analysis on foraminifers and calcareous nannoplankton confi rms this age. The studied sediment was deposited in the transition to shallow marine environment as indicated by rare occurrence of marine microfossils. The common brackish pollen of Zonocostites ramonae (Rizophora) and Spinizonocolpites echinatus (Nypa) indicates mangrove/ back-mangrove environment. Moreover, the domination of shallow water benthonic over the planktonic forms suggests shallow marine setting.
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Sachoemar, Suhendar. "VARIABILITY OF SEA SURFACE CHLOROPHYLL-A, TEMPERATURE AND FISH CATCH WITHIN INDONESIAN REGION REVEALED BY SATELLITE DATA." Marine Research in Indonesia 37, no. 2 (2015): 75–87. http://dx.doi.org/10.14203/mri.v37i2.25.
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The investigation of sea surface chlorophyll-a (SSC) and sea surface temperature (SST) in relation to fish catch variability within the Indonesian region were conducted by using satellite data of NOAA-AVHRR, SeaWiFs and Aqua MODIS. The investigation focused in the region of the coastal area of Java, Lampung Bay and South Kalimantan as representation of the environment diversities of the Indonesian seas. The result shows that seasonal variation in fish productivity has a strong correlation with SSC variability. High fish productivity corresponded well with high concentration of SSC, and the productivity tended to decrease when the SSC concentration was declined. High SSC variability in the coastal area of Java and Lampung Bay was governed by the upwelling that induced high nutrient load into the sea surface during the southeast monsoon, while in the northern coastal area of Java and South Kalimantan, it was governed by high precipitation ocurring during the northwest monsoon that enhanced the nutrient load through the rivers and coastal discharge.
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Syahputra, Reza, Felix Muria Hasudungan Sihombing, and Octria Adi Prasojo. "Correlation Between Fracture Azimuth, Surface Lineaments and Regional Tectonics: A case study from Belik District, Central Java, Indonesia." Journal of Geoscience, Engineering, Environment, and Technology 4, no. 1 (2019): 22. http://dx.doi.org/10.25299/jgeet.2019.4.1.2294.
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Two major strike-slip faults with northeast-southwest and northwest-southeast orientation have shifted the southern Central Java, including Belik District. Consequently, many smaller faults that have the same direction as the major faults and west-east direction folding systems were emerged. The orientation of these geologic structures could be observed from morphological features such as ridge and river. A quantitative approach was carried out to unravel the impacts of those geologic structures on the geomorphology of the study area, which is located between Slamet Mountain and Sindoro Mountain, Central Java province. The method used in this research was the structural geology analysis, including the interpretation of ridge and river lineament, the distribution of fractures, and statistical analysis. The research location is divided into four different segments based on its lineament and morphology. The lineament that has similar characteristics was tested using normality test of Kolmogorov-Smirnov. The Spearman test was used to obtain the correlation between surface lineament and fracture azimuth. All fracture azimuth, ridges and rivers tend to have northwest-southeast and northeast-southwest direction. These results show similar direction with strike-slip regional structural pattern. The statistical calculation and field observation indicate the influence of external factor on the change of the study area’s landform.
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Apriansyah, Agus S. Atmadipoera, Dwiyoga Nugroho, and Rinda Noviyanti. "Shelf oceanography and small pelagic fishes in the Java Sea." E3S Web of Conferences 483 (2024): 01010. http://dx.doi.org/10.1051/e3sconf/202448301010.
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The optimization of small pelagic fisheries in the Java Sea could be enhanced by providing oceanographic information for analysis and determining potential fishing grounds. This study aims to investigate shelf oceanographic factors influencing small pelagic fisheries using multidatasets of sea surface temperature and surface salinity CROCO ocean model output (2010 – 2020), distribution of light-fishing vessel position of VIIRS satellite, and small pelagic fish catches landing data (round scads Decapterus spp. and the spotted sardinella Amblygaster sirm) at Pekalongan Fishing Port, Central Java. The results showed that the peak of fishing season for the spotted sardinella occurs during northwest monsoon, in which the eastward monsoon current and Sunda shelf throughflow brings fresher (±32.4 psu) and warmer (±28.5 oC) water into the Java Sea. In contrast, the peak of fishing season for round scads. is associated with saltier (>33.0 psu) and cooler (<28.5 °C) water supplied by the westward monsoon current and Makassar ITF during the southeast monsoon. Alternating intensification of monsoonal current along the northern Java and the southern Kalimantan coast during different monsoon periods is associated with a higher abundance of neritic and oceanic small pelagic fishes, respectively.
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Yuliana, Yuliana, Tasari Tasari, Anita Setiyaningsih, Fika Aisyah Munif, and Miftacha Febriani Putri. "Optimalisasi Biaya Transportasi Produk UMKM Naturies Indonesia Dengan Metode Northwest Corner Dan Vogel’s Approximation." Jurnal Derivat: Jurnal Matematika dan Pendidikan Matematika 9, no. 2 (2022): 246–57. http://dx.doi.org/10.31316/jderivat.v9i2.3138.
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Naturies Indonesia is one of the UMKM for spice drinks in Macanan, Klaten, Central Java which is developing. As one of the growing UMKM, Naturies Indonesia is experiencing problems related to the distribution of its products. Naturies Indonesia has incurred transportation costs of Rp.442,100.00 per week in distributing its products to 5 distributors (Kudus, Jakarta, Shopee, Bandung, and offline). Due to human resource constraints, Naturies Indonesia does not yet have a thorough plan to reduce shipping costs in allocating products from production sites to customers or distributors. Through this applied research, this research aims to find the optimization of product delivery costs. Data were collected through interviews and documentation, then analyzed using the Northwest Corner and Vogel's Approximation methods. Analysis using the Northwest Corner method found a shipping cost of IDR 431,600.00, while the Vogel's Approximation method found a shipping cost of IDR 427,900.00. The shipping costs found were actually lower than the financing that had been issued so far. Keyword: northwest cor, spice drinks, optimization of transportation, UMKM Naturies Indonesia, vogel’s approximation
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Maulida, Putra, Muhammad Rafiq, Yola Asis Herawati, Akbar Kurniawan, and Muhammad Taufik. "Current deformation in eastern part of Java derived from GPS observation 2017-2022." IOP Conference Series: Earth and Environmental Science 1276, no. 1 (2023): 012023. http://dx.doi.org/10.1088/1755-1315/1276/1/012023.
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Abstract The eastern part of Java Island is a prone area with high seismic potential. Geologically, the seismicity in this area is dominated by the subduction zone in southern Java, reverse faults structure in the north extending along east to west part of Java Islands, and normal faults in Pasuruan and Probolinggo. Several studies have indicated the potential of earthquakes associated with these sources. The geodetic technique is employed to monitor the deformation activity in the eastern part of Java to understand the characteristics. We utilized the continuous GPS stations operated by Geospatial Agency of Indonesia (BIG) and processed them using the GAMIT/GLOBK software. The processing incorporates the IGS stations surrounding Indonesia. We also used precise orbit and 2nd-order ionospheric correction. The processing produces the velocity in the ITRF2014 reference frame, which generally indicates the south-eastward velocity up to 29 mm/year, mainly influenced by block rotation. Velocity referenced to the Sunda block shows a distinguished pattern between southern Java and northern Java. The velocity pattern in the southern part of Java tends to move northwest with a velocity variation of 3-6 mm/year, while several north stations show a velocity pattern to the south with a variation of 2-4 mm/yr. The strain analysis shows different patterns between eastern and western regions and different characteristics of southern and northern regions. Mainly the deformation is dominated by the compression due to the subduction in the south. Meanwhile, near to the central Java the deformation patterns significantly change due to the appearance of the east-west extension. The result indicates the different distinguished characteristics of the deformation source in the eastern part of Java. This result will have implications for seismic hazard analysis as a contribution to disaster risk reduction in the future.
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Lelono, Eko Budi. "Gondwanan Palynomorphs From The Paleogene Sediments Of East Java The Evidence Of Earlier Arrival." Scientific Contributions Oil and Gas 30, no. 2 (2022): 1–12. http://dx.doi.org/10.29017/scog.30.2.864.
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The palynological investigation of the Paleogene sediments is based on cutting samples collected from the exploration wells which are drilled in East Java area. The occurrence of pollen Meyeripollis naharkotensis and spore Cicatricosisporites dorogensis in the upper well sections suggests the pollen zone of Meyeripollis naharkotensis which is equivalent to Oligocene age. Meanwhile, the occurrence of pollen Proxapertites operculatus and spore Cicatricosisporites eocenicus below Meyeripollis naharkotensis zone indicates the appearance of Proxapertites operculatus zone within the lower sections which is equivalent to Eocene. In addition, foraminiferal and nannoplankton analyses confirm the Oligocene-Eocene age by identifying the occurrence of letter stage of Te4-Tb and nanno zone of NP20-P25. The appearance of the Gondwanan/Australian elements including Dacrydium and Casuarina with common and regular occurrences throughout the studied sections are controversial as these pollen were firstly recorded in the younger sediments (Early Miocene) of other areas such as Northwest Java sea, South Sumatra and Natuna sea following the collision of the Australian plate and the Sundaland in the latest Oligocene. Furthermore, the absence of these palynomorphs within the Paleogene sediments of Central Java and South Sulawesi strengthens the above assumption. Therefore, in regard to East Java, the appearance of Dacrydium and Casuarina may indicate earlier arrival of the Gondwanan/ Australian fragment in this area compared to that in other areas of Indonesia.
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Irawan, Sudra, and Muhammad Zainuddin Lubis. "Geology Structure Identification Using Pre-Stack Depth Migration (PSDM) Method of Tomography Result in North West Java Basin." Journal of Geoscience, Engineering, Environment, and Technology 2, no. 2 (2017): 117. http://dx.doi.org/10.24273/jgeet.2017.2.2.297.
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North West Java Basin is a tertiary sedimentary basin which is located in the right of the western part of the Java island. North West Java Basin is geodynamic where currently located at the rear position of the path of the volcanic arc of Java that is the result of the India-Australia plate subduction to the south towards the Eurasian plate (Explanation of Sunda) in the north. Geology structure observation is difficult to be conducted at Quaternary volcanicfield due to the classical problem at tropical region. In the study interpretation of fault structures can be done on a cross-section of Pre-Stack Depth Migration (PSDM) used prayer namely Hardware Key Device, ie Central Processing Unit: RedHat Enterprise Linux AS 5.0, prayer Monitor 24-inch pieces, Server: SGI altix 450/SuSe Linux Enterprise Server 9.0, 32 GB, 32 X 2,6 GHz Procesor, network: Gigabyte 1 Gb/s, and the software used is paradigm, product: Seismic Processing and Imaging. The third fault obtained in this study in accordance with the geological information derived from previous research conducted by geologists. The second general direction is northwest-southeast direction represented by Baribis fault, fault-fault in the Valley Cimandiri and Gunung Walat. This direction is often known as the directions Meratus (Meratus Trend). Meratus directions interpreted as directions that follow the pattern of continuous arc Cretaceous age to Meratus in Kalimantan.
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KNIGHT, G. ROGER. "Exogenous Colonialism: Java Sugar between Nippon and Taikoo before and during the Interwar Depression, c. 1920–1940." Modern Asian Studies 44, no. 3 (2009): 477–515. http://dx.doi.org/10.1017/s0026749x08003727.
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AbstractThis paper discusses the commercial history of the Java sugar industry in the interwar decades of the 1920s and 1930s. Java's late colonial industry had a uniquely exogenous character, in that, amongst the world's major producers of cane sugar in the late colonial era, it was singularly devoid of metropolitan or quasi-metropolitan markets. Instead, it sought its markets pre-eminently on the Asian ‘mainland’ to its north and northwest. The Indian subcontinent formed one such market, but East Asia formed the second, and it is the Java industry's fortunes in China and Japan that provide the focus of the present paper. This focus highlights the extent to which the partial collapse of the industry in the mid-1930s related to factors altogether more complex than a simple fall in consumption and drop in prices associated with the interwar Depression. Fundamentally, it was evolving economic autarchy throughout east Asia, encouraged by Depression conditions, which lay at the heart of the Java sugar industry's problems in this sector of its market. Key factors were Java's ambivalent relationship with an expanding but crisis-ridden Japanese sugar ‘empire,’ and the effect on its long-standing links with British sugar refineries in Hong Kong because of the latter's increasing difficulties in the China market. In tandem, they underscored the commercial hazards inherent in Java sugar's exogenous situation.
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Setyawan, Agus, Agnis Triahadini, Yayan Yuliananto, Yoga Aribowo, and Dian Agus Widiarso. "Subsurface Structure and Fluid Flow Analysis Using Geophysical Methods in the Geothermal Manifestation Area of Paguyangan, Brebes, Central Java." International Journal of Renewable Energy Development 5, no. 3 (2016): 171–77. http://dx.doi.org/10.14710/ijred.5.3.171-177.
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The indication of an active geothermal system is shown by the presence of surface manifestations such as the hot spring in Kedungoleng, Paguyangan, Brebes, Central Java. The temperature of the largest hot spring reaches 74o C and there is an assumption that this is an outflow of Mount Slamet geothermal system. DC-resistivity, Spontaneous Potential (SP) and Shallow Surface Temperature surveys were conducted to determine the subsurface structure as well as its correlation with the distribution of thermal fluid flow and shallow surface temperature. The subsurface resistivity has been investigated using 5 points of the Schlumberger configuration with 400 m separation for each point. For the fluid and temperature pattern, a measurement using 15 m interval in 3 lines of conducting fixed electrode configuration has been carried out, along with a 75 cm of depth of temperature measurement around the manifestation area. The thermal fluid is assumed by the low resistivity of 0.756 to 6.91Ωm and this indicates sandstone that has permeable characteristic. The fluid flows in two layers of Sandstone at more than 10 meter from surface of the first layer. Accordingly, the SP values have a range between -11- 11 mV and a depth interval of 13.42- 28.75 m and the distribution of temperature is between 24o-70oC at a tilting range of 46.06o-12.60o. Hence it can be inferred that the thermal fluid moves in the Northwest direction and is controlled by a fault structure stretching from Northwest to Southeast.Article History: Received Feb 3, 2016; Received in revised form July 11, 2016; Accepted August 13, 2016; Available onlineHow to Cite This Article: Setyawan, A., Triahadini, A., Yuliananto, Y., Aribowo, Y., and Widiarso, D.A. (2016) Subsurface Structure and Fluid Flow Analyses Using Geophysical Methods in Geothermal Manifestation Area of Paguyangan, Brebes, Central Java. Int. Journal of Renewable Energy Development, 5(3), 171-177.http://dx.doi.org/10.14710/ijred.5.3.171-177
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Hisan, Nazwa Khoiratun, Ludovikus Damardika Jasaputra, and Pius Artdanno Bernaldo. "Hydrostructure of Groundwater Manifestation of Gedongsongo Geothermal Ungaran, Semarang, Central Java, Indonesia." Journal of Earth and Marine Technology (JEMT) 1, no. 1 (2020): 31–39. http://dx.doi.org/10.31284/j.jemt.2020.v1i1.1150.
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Groundwater is an important element of the hydrological cycle in geothermal systems. The geological structure of the Plio-Pleistocene volcano and different lithological variations affect the type and response of groundwater to rocks. The research area is located around the Gedongsongo Temple complex, Mount Ungaran, Central Java. Based on the field check location, there are three variations of lithology, the first lithology is a breccia with andesite, basalt, and pyroclastic fragments. The NW-SE-oriented geological structure is flattened to the right slip fault which is the fracture aquifer system on the Southern Slope of Mount Ungaran. In the research area, there is an anomaly in the form of deflection of flow direction pattern caused by structural control factor in the form of fracture, the fracture which becomes the fluid channel media is a tension joint on the shear zone with Northwest strike with dip direction toward Northeast which has NW-SE orientation of right slip fault.
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Nuha, Dafiqiy Ya'lu Ulin, Sukir Maryanto, and Didik Rahardi Santoso. "DETERMINATION OF THE DIRECTION OF HOT FLUID FLOW IN CANGAR AREA, ARJUNO-WELIRANG VOLCANO COMPLEX, EAST JAVA USING SELF POTENTIAL METHOD." Jurnal Penelitian Fisika dan Aplikasinya (JPFA) 7, no. 2 (2017): 123. http://dx.doi.org/10.26740/jpfa.v7n2.p123-132.
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Research with self potential method has been done in Cangar area of Arjuno-Welirang volcano complex, East Java. The purpose of this study was determined the direction of hot fluid flow. This hot fluid forms a geothermal manifestation of hot springs. Data acquisition has been done using fixed electrode configuration with interval 5 meters in 5 lines. In this configuration there are two porous pot electrodes, one of them set in fixed station and the other as mobile station. Based on the potential distribution value of the isopotential map, the lowest potential value about -54,5 mV and the highest value about 89,4 mV, so that in Cangar area can predicted the direction of hot fluid flow from southeast to northwest. Based on the results of this research in the direction of hot fluid flow can provide information about hydrothermal system in Cangar area for study of geothermal potential of Arjuno-Welirang Volcano complex, East Java
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Hafiz, Surya Darma, Ahmad Helman Hamdani, Budi Muljana, and Moeh Ali Jambak. "Effect of diagenetic events on limestone reservoir quality: Case study of Parigi formation, Northwest Java basin." BIO Web of Conferences 73 (2023): 04009. http://dx.doi.org/10.1051/bioconf/20237304009.
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Limestone is a sedimentary rock with high heterogeneity. This is triggered by diagenetic processes that affect the quality of limestone during its formation. The high uncertainty in limestone porosity values is also influenced by diagenetic processes. The Parigi Formation is a carbonate rock located in the Northwest Java Basin and has been proven to be a carbonate reservoir rock. Petrographic analysis was conducted to observe the appearance resulting from diagenetic processes. The studied area's limestone has two facies: clastic facies and reef facies. The limestone of clastic facies is white to greyish, consisting of skeletal fragments or shell fragments, with some places contains fragmented coral fragments. It is grain-supported, massive, poorly sorted, with fragment sizes ranging from 1mm-8mm and in some places 10cm-20cm. The reef facies of limestone are generally white to greyish colour, compact/massive, without cavities, and shows the body structure of coral/reef. The processes occurring in the Parigi Formation limestone, based on thin-section data, include cementation and neomorphism, which are commonly found in thin section LP 7 and LP 10. Cementation and neomorphism lead to a decrease in porosity in the limestone. Samples LP 1 - LP 5 show extensive dissolution, resulting in vuggy cavities/porosity. These limestone samples have high porosity values. The transformation of fossils into new crystals or recrystallization processes also reduces the limestone's porosity. Some samples also show that the cavities in the Parigi Formation limestone have been filled by calcite cements, thus closing the pores. This leads to poor quality limestone. In conclusion, the heterogeneous nature of limestone is significantly influenced by diagenetic processes. Petrographic analysis of the Parigi Formation limestone revealed the occurrence of cementation, neomorphism, dissolution, and recrystallization processes, all of which have implications for porosity and reservoir quality.
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Mandal, Samiran, Raden Dwi Susanto, and Balaji Ramakrishnan. "On Investigating the Dynamical Factors Modulating Surface Chlorophyll-a Variability along the South Java Coast." Remote Sensing 14, no. 7 (2022): 1745. http://dx.doi.org/10.3390/rs14071745.
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Twelve years of remotely sensed all-sat merged chlorophyll-a concentration unveils strong signatures of chlorophyll-a blooms along the south Java coast. An unprecedented three-times increase in chlorophyll-a concentration is significantly observed along the south Java coast during the southeast monsoon (June–October) than the northwest monsoon (December–April). The multiple regression analysis of dynamic factors evidently indicates that seasonal upwelling is predominantly controlled by the seasonally evolving coastal eddies associated with the seasonally reversing south Java coastal currents (SJCC) and Ekman mass transport (EMT), followed by the relative roles of sea surface temperature (SST) and wind stress curl. The eddy-induced upwelling and EMT-induced coastal upwelling lead to chlorophyll-a blooms during southeast monsoon, well-supported by the entrainment of cold and saline waters (thermocline doming) with low spiciness. On the other hand, the coastal eddies associated with SJCC and SST anomalies play a significant role in modulating the interannual surface chlorophyll-a variability in the domain. Intense chlorophyll-a blooms are observed during the positive IOD years, whereas the least chlorophyll-a concentration is observed during the negative IOD years. The unprecedentedly least chlorophyll-a concentrations during 2010 and 2016 are attributed to the intense and prolonged surface marine heatwaves.
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Hakim, Bagus Iqbal, Udi Harmoko, and Sugeng Widada. "GROUNDWATER FLOW PATTERN AROUND GONOHARJO HOT SPRING, KENDAL REGENCY, CENTRAL JAVA." Cognizance Journal of Multidisciplinary Studies 3, no. 11 (2023): 196–204. http://dx.doi.org/10.47760/cognizance.2023.v03i11.013.
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The Ungaran Mountain is a stratovolcano-type volcano with a geothermal system. On the northern side of Mount Ungaran, there are hot springs located in the Gonoharjo area, Kendal Regency, Central Java, Indonesia. These hot springs appear on the mountain slopes and are very close to the surface water. This research aims in analyzing the pattern of groundwater flow with surface water flow around the springs and identifying the relationship that occurs between the springs and the nearest river flow. Analysis of the groundwater flow pattern can be determined based on groundwater level contour maps and groundwater flow maps. Such mapping can occur by plotting groundwater level data measured from 16 springs scattered on the slopes of Mount Ungaran. As a result of the measurements taken, the groundwater level ranged from 298.02 m above sea level to 818.47 m above sea level. The highest groundwater level is in the Pakis area while the lowest groundwater level is in the Boja area. The groundwater flow pattern at the study site flows from the top of the mountain and spreads to the north, northwest, west, southwest. Based on the 15 cross sections conducted, it can be identified that in general the relationship between groundwater and rivers flow in the study area is that most of the groundwater supplies surface water.
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Dewanto, Ordas, Rahmat Catur Wibowo, Darsono, and Aryka Claudia Eka Putri. "The implementation of well logging method, geochemical analysis, and seismic method to determine source rock potentials at field “X”, Northeast Java Basin." Journal of Physics: Conference Series 2498, no. 1 (2023): 012050. http://dx.doi.org/10.1088/1742-6596/2498/1/012050.
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Abstract East Java is an area with the potential to produce oil and gas. Oil and gas are hydrocarbon mix produced from the subsurface, sourced from matured organic materials, and migrated to be drilled to be produced into oil and gas. The methods to explore oil and gas are well logging and seismic methods. Combining both methods can obtain vertical and horizontal subsurface information. The study was performed by analyzing secondary data processing results of wells, seismic data, and ko chemistry data. Geochemical data were used to analyze source rock potentials in the study area. Source rock is rock containing organic materials to produce hydrocarbons. Therefore, this study aimed to determine source rock potentials. Using the three methods, it concludes that Field “X” as the study site in the northeast Java, can produce hydrocarbons on the northwest region of the study area because the source rock zone at Field “X” has a 3.87% TOC with type II kerogen. Although the source rock is immature, it can produce oil and gas.
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Sidik, Firdos Bahar, Rama Wahyu Nurawi, Haris Muhlisin, Wrego Seno Giamboro, and Wahyu Hidayat. "Identification of Andesite Rocks Using Dipole-Dipole Geoelectric Method in Batursari Subdistrict, Pekalongan Regency, Central Java." East Asian Journal of Multidisciplinary Research 2, no. 10 (2023): 4149–60. http://dx.doi.org/10.55927/eajmr.v2i10.6459.
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A study has been conducted to identify andesite rocks using the dipole-dipole geoelectric resistivity method in the Batursari Subdistrict, Pekalongan Regency, Central Java Province. Measurements were taken along 12 Lines stretching from northwest to southeast, with a Line length of 280 m and electrode spacing of 10 m. The aim of this research was to model the 2D resistivity value Line of the path, determine the type of andesite rock, and assess the depth of the rock in the study area. Based on data processing results, four lithology units were identified: resistivity values ranging from 0 to 150 Ωm were interpreted as soil, 150 to 250 Ωm as weathered andesite, 250 to 400 Ωm as moderate andesite, and resistivity values from 400 Ωm to 3000 Ωm were interpreted as fresh andesite.
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Cai, Wenju, Harry H. Hendon, and Gary Meyers. "Indian Ocean Dipolelike Variability in the CSIRO Mark 3 Coupled Climate Model." Journal of Climate 18, no. 10 (2005): 1449–68. http://dx.doi.org/10.1175/jcli3332.1.
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Abstract Coupled ocean–atmosphere variability in the tropical Indian Ocean is explored with a multicentury integration of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Mark 3 climate model, which runs without flux adjustment. Despite the presence of some common deficiencies in this type of coupled model, zonal dipolelike variability is produced. During July through November, the dominant mode of variability of sea surface temperature resembles the observed zonal dipole and has out-of-phase rainfall variations across the Indian Ocean basin, which are as large as those associated with the model El Niño–Southern Oscillation (ENSO). In the positive dipole phase, cold SST anomaly and suppressed rainfall south of the equator on the Sumatra–Java coast drives an anticyclonic circulation anomaly that is consistent with the steady response (Gill model) to a heat sink displaced south of the equator. The northwest–southeast tilting Sumatra–Java coast results in cold sea surface temperature (SST) centered south of the equator, which forces anticylonic winds that are southeasterly along the coast, which thus produces local upwelling, cool SSTs, and promotes more anticylonic winds; on the equator, the easterlies raise the thermocline to the east via upwelling Kelvin waves and deepen the off-equatorial thermocline to the west via off-equatorial downwelling Rossby waves. The model dipole mode exhibits little contemporaneous relationship with the model ENSO; however, this does not imply that it is independent of ENSO. The model dipole often (but not always) develops in the year following El Niño. It is triggered by an unrealistic transmission of the model’s ENSO discharge phase through the Indonesian passages. In the model, the ENSO discharge Rossby waves arrive at the Sumatra–Java coast some 6 to 9 months after an El Niño peaks, causing the majority of model dipole events to peak in the year after an ENSO warm event. In the observed ENSO discharge, Rossby waves arrive at the Australian northwest coast. Thus the model Indian Ocean dipolelike variability is triggered by an unrealistic mechanism. The result highlights the importance of properly representing the transmission of Pacific Rossby waves and Indonesian throughflow in the complex topography of the Indonesian region in coupled climate models.
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Putra, D. R., N. M. N. Natih, and A. Purwandana. "Seasonal variation of mixed layer depth and thermocline thickness from the ctd argo float data in the Southern Makassar Strait." IOP Conference Series: Earth and Environmental Science 1137, no. 1 (2023): 012010. http://dx.doi.org/10.1088/1755-1315/1137/1/012010.
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Abstract The Makassar Strait (MS) is directly connected to the Sulawesi Sea in the north and the Java Sea and the Flores Sea in the south and is the main route of Indonesia Throughflow(ITF). Hence Stratification of water mass in the MS is influenced by the dynamics of these waters. This study aims to describe seasonal variations of the mixed layer depth and the thermocline thickness, identify ITF water masses, and the occurrence of coastal upwelling in the southern part of the MS. The results show that the North Pacific water origin of North Pacific Subtropical Water (NPSW) and North Pacific Intermediate Water (NPIW) are dominant, with a maximum salinity characteristic of 34.6-34.7 psu in the thermocline layer and a minimum salinity of 34.5 psu in the intermediate layer. However, near-surface fresh Java Seawater appears to be dominant during the northwest monsoon (NWM-DJF) period. Seasonal variation of the mixed layer depth is much deeper (93m) and vertical gradient of temperature and salinity are much stronger due to the presence of fresh Java Sea water advected by the eastward Java Monsoon Current. However, during the southeast monsoon (SEM-JJA) period the mixed layer depth is much shallower and the thermocline layer is much thicker (198 m), Associated with much stronger ITF and upwelled colder water from the upwelling area. The coastal upwelling event during the SEM period in the study are is characterized by an increase of isotherm of 25 °C, isohaline of 34.0 psu, and isopycnal of 22.0 kg/m3 from about 75 m depth to the sea surface layer.
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Vermeij, Geerat J., and Han Raven. "Southeast Asia as the birthplace of unusual traits: the Melongenidae (Gastropoda) of northwest Borneo." Contributions to Zoology 78, no. 3 (2009): 113–27. http://dx.doi.org/10.1163/18759866-07803003.
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In this paper the Miocene to recent melongenid species of northwest Borneo are discussed. The recent fauna is poor with three genera represented by one species each. In the Miocene three (possibly four) genera occur with eight (possibly nine) species of which three are described as new species: Melongena murifactor, uniquely characterized by the formation of a septum walling off the adapical sector of the aperture; Pugilina erecta, characterized (along with its close Miocene relative from Java, P. ickei) by a free-edged, erect inner lip; Volema goliath, large for the genus with later whorls progressively covering the upper row of spines of earlier whorls. The apertural septum of M. murifactor is unique within Gastropoda, whereas the erect inner lip of P. erecta and P. ickei is unique within Melongenidae. That these extralimital traits occur exclusively in the Miocene of southeast Asia is consistent with the hypothesis that adaptive innovations are most likely to arise in diverse, productive, shallow-water ecosystems.
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Semedi, Bambang, Hardoko Hardoko, Citra Satrya Utama Dewi, Nova Dewi Safitri Syam’s, Novia Fara Diza, and Gerardus David Ady Purnama Bayuaji. "Seasonal Migration Zone of Skipjack Tuna (Katsuwonus pelamis) in the South Java Sea Using Multisensor Satellite Remote Sensing." Journal of Marine Sciences 2023 (July 7, 2023): 1–14. http://dx.doi.org/10.1155/2023/1073633.
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Skipjack tuna (Katsuwonus pelamis) is the most dominating tuna species caught in the Indian Ocean. However, tuna fishermen in the Indian Ocean still face difficulties determining potential skipjack tuna fishing grounds due to limited geographic information. An attempt to improve information regarding potential skipjack tuna fishing grounds is through modeling the SST, SSC, SSH, and SSS oceanographic parameters with skipjack tuna distribution using GIS. The characteristics of the skipjack tuna habitat can be found through the generalized additive model (GAM) statistical analysis using data of skipjack tuna catch and oceanographic parameters from satellite imagery. The integrated GIS and GAM methods can improve the study of the habitat of skipjack tuna species. Therefore, this research is aimed at analyzing the condition and SST, SSC, SSH, and SSS variations in 2016-2021 in the South Java Sea; at predicting the correlation of SST, SSC, SSH, and SSS towards skipjack tuna catch in 2016-2021 in the South Java Sea using GAM; and at creating a map of skipjack tuna seasonal migration zones. The data included skipjack tuna catches, number of trips, and skipjack tuna fishing coordinates in 2016-2021 from PPS Cilacap and PPP Pondokdadap. The oceanographic parameter data in 2016-2021 was derived from Aqua MODIS level 3 (SST and SSC) and CMEMS (SSH and SSS) satellite imagery. The results showed that the average values of oceanographic parameters at skipjack tuna fishing ground coordinates in the South Java Sea (2016-2021) were SST (26.050-30.816°C), SSC (0.094-0.564 mg/m3), SSH (0.268-0.639 m), and SSS (33.075-34.514 psu). The best GAM modeling was the combination of four oceanographic parameter variables with an AIC value of 45357.92. Skipjack tuna in the South Java Sea migrates southeast during the west monsoon season to the first transitional season and tends to migrate northwest during the east monsoon season to the second transitional season.
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Jordaan, Roy, and Brian Colless. "The Ratu Boko Mantra And The Sailendras." Berkala Arkeologi 24, no. 1 (2004): 56–64. http://dx.doi.org/10.30883/jba.v24i1.894.
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The Ratu Boko (or Ratu Baka) plateau, near Yogyakarta in southern central Java, is surrounded by an impressive array of Hindu and Buddhist shrines. Notable among these are the Prambanan temples to the north, and Candi Kalasan to the west, with the massive Borobudur stupa 40 kilometres to the northwest, and the lofty volcanoes Merapi and Merbabu towering over the northern landscape. The presence of dynamic mountains and Buddhist monuments makes the Ratu Boko heights an ideal spot for locating the lost palace of the Sailendra 'mountain lords', though they may well have resided on the plain or in a northern port. However that may be, Ratu Boko was the site of the famous Sailendra monastery, Abhayagirivihara, which had links with Sri Lanka.
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Hall, G. B., F. Wang, and Subaryono. "Comparison of Boolean and Fuzzy Classification Methods in Land Suitability Analysis by Using Geographical Information Systems." Environment and Planning A: Economy and Space 24, no. 4 (1992): 497–516. http://dx.doi.org/10.1068/a240497.
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In this paper the information content of Boolean and fuzzy-set-based approaches to the problem of analyzing land suitability for agriculture within a geographical information system (GIS) is assessed. First, the two approaches to this problem are stated and formalized in the context of land-suitability evaluation. A database comprising 642 unique areas, 7 land qualities, 13 land characteristics, and 2 crop types is defined and described. Land-use suitability ratings for two crops, wetland rice and soybean, are generated by using Boolean and fuzzy methods. Results produced by the two methods are compared in terms of their usefulness for agricultural land-use plannning. The ARC/INFO vector-based GIS software package is utilized. The study area is the Cimanuk watershed in northwest Java, Indonesia.
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Taryana, Didik, Rudi Hartono, Dicky Arinta, Agus Purnomo, and Ike Sari Astuti. "Landslide Movement of Bendungan District Trenggalek Using an Artificial Neural Network." Environmental Research, Engineering and Management 79, no. 3 (2023): 95–107. http://dx.doi.org/10.5755/j01.erem.79.3.33628.
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Landslide is one of the disasters that often occurs in Indonesia in the East Java Province, especially in Bendungan District, Trenggalek Regency. Analysis of landslide susceptibility in Bendungan District is needed to spatially locate the landslide occurrences. The purpose of this study was to predict landslide events using an artificial neural network. Rainfall, topography, physical soil properties, and land-use were used as the explanatory variables. An analytic hierarchy process approach was applied to determine the weight of the variables. The model satisfactorily classified the landslide hazards with an area under curve of 0.96. The northwest area of the Bendungan District was found to be a region at high risk with rainfall and soil texture as the most influential parts in triggering the landslides.
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Hamzah, F. "Nitrate and phosphate profiles in the Banda Sea during the northwest monsoon." IOP Conference Series: Earth and Environmental Science 1163, no. 1 (2023): 012002. http://dx.doi.org/10.1088/1755-1315/1163/1/012002.
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Abstract The Banda Sea (BS) is subjected to monsoonal winds that affected upwelled rich nutrient waters and primary production. However, nutrient characteristic in the region is less constrained. Here, we examine nitrate and phosphate profiles in the Banda Sea from data collected during the northwest monsoon. Waters along the surface density (σθ ) < 22 were dominated by less saline originating from western Indonesia (i. e., Java Sea), accompanied by Indonesian throughflow water Banda (23.0-25.0σθ ) and Banda water (26.5-27.0σθ ), respectively. Surface water was accompanied by low nitrite+nitrate ( N O 2 − + N O 3 − ) and phosphate ( P O 4 3 − ), meanwhile, the average N O 2 − + N O 3 − and P O 4 3 − concentrations in the upper 500 m were slightly higher in the western part than those in the eastern part suggesting additional sources from upwelled waters. Furthermore, the average nitrite+nitrate to phosphate ratio (N:P ratio) was 11.2:1, indicating nitrogen is a limiting factor for the growth of primary producers, and other sources may play a more dominant role. Two distinct layers in the euphotic zone within different sources and mechanisms namely the nutrient-depleted layer and nutrient-repleted layer were observed. Overall, the result of this study can only be seen as a starting point toward a comprehensive and holistic understanding of the nutrient biogeochemistry of the Indonesia Seas.
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Abimanyu, Amarif, Widodo S. Pranowo, Ibnu Faizal, Najma K. A. Afandi, and Noir P. Purba. "Reconstruction Of Oil Spill Trajectory In The Java Sea, Indonesia Using Sar Imagery." GEOGRAPHY, ENVIRONMENT, SUSTAINABILITY 14, no. 1 (2021): 177–84. http://dx.doi.org/10.24057/2071-9388-2020-21.
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Oil spill phenomena in the ocean possess a very serious threat to ocean health. On the ocean surface, oil slicks immediately start to spread and mostly end up in the ecosystem. Furthermore, it could threaten the organisms living in the ocean or impact nearby coastal area. The aim of this research was to investigate the trajectories of oil spill based on a real accident in the Java Sea. Tracking oil spills using satellite images is an efficient method that provides valuable information about trajectories, locations and the spread intensity. The objective of this study was to periodically track the trajectory of the oil spill from the Karawang incident using Sentinel-1 Synthetic Aperture Radar (SAR) images. Pre-processing of the images consisted of radiometric and geometric corrections. After the corrections, SAR images were mapped and plotted accordingly. To understand the oil spill trajectories in relation to the oceanic processes, the ocean current pattern map and surface wind roses were also analysed. The processed images from July to October 2019 show a trajectory dominated by the oil spill layers movement towards the west to northwest from the original location along with a decrease in the detected oil spill area over time. The identified trajectories of the oil spill followed the ocean current pattern and surface winds. Thus, these two parameters were considered to be the main factors responsible for the oil spill drift.
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Mulyana, Erwin. "ANALISIS CUACA PADA SAAT PELAKSANAAN TMC PENANGGULANGAN BANJIR JAKARTA JANUARI FEBRUARI 2014." Jurnal Sains & Teknologi Modifikasi Cuaca 16, no. 1 (2015): 15. http://dx.doi.org/10.29122/jstmc.v16i1.2634.
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AbstrakPada tanggal 11 Januari sampai dengan 14 Februari 2014 telah dilaksanakan penerapan teknologi modifikasi cuaca (TMC) untuk menanggulangi banjir di wilayah Jakarta dan sekitarnya. Selama kegiatan tersebut fenomena ENSO dan IOD dalam kondisi normal. MJO menunjukkan aktifitas konvektif netral di wilayah Indonesia pada pertengahan Januari hingga pertengahan Februari 2014. Temperatur permukaan laut di perairan Jawa bagian barat sekitar 28-290C. Kelembagan udara pada level 850 mb sekitar 70-80%. Pertumbuhan awan umumnya berada di sebelah barat daya, barat dan barat laut Jakarta. Indeks Monsoon Australia positif berpengaruh terhadap peningkatan pembentukan awan hujan di Jawa.Abstract Application of weather modification has carried out to reduce precipitation over Jakarta on 11 January to 14 February 2013. During this period, El Nino Southern Oscillation and Indian Ocean Dipole Mode were normal condition. The Madden Julian Oscillation shows that the convection over Indonesia region was netral condition. The sea surface temperature over west part of Java waters was 29-30 290C. The 850 mb average of relative humidity on mid January - mid February 2014 was 70-80%. Based on visual and weather radar observation, cloud development mainly over northwest to southwest of Jakarta. Positive Australian Summer Monsoon Index affected to increase precipitation over Java area.
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Itsnaini, Nur, Doni Prakasa Eka Putra, and I. Gde Budi Indrawan. "Hydrogeological and hydrochemical condition in planned tunnel B route of the Yogyakarta-Bawen toll road." E3S Web of Conferences 479 (2024): 02007. http://dx.doi.org/10.1051/e3sconf/202447902007.
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The Yogyakarta-Bawen toll road tunnel, located in Magelang Regency, Central Java Province, is a national strategic project that connects Central Java and the Special Region of Yogyakarta. It has geology resulting from volcanic processes, resulting in rocks with moderate aquifer properties and low to moderate permeability. The study covers 24 observation points, with 11 locations sampling groundwater for chemical analysis. The analysis results of hydrochemical facies are Na-K-HCO3. Water table depth varies from 623 m to 704 m above sea level, with the water table along the tunnel route at depths of 13-40 m above mean sea level, generally above the tunnel’s elevation. The groundwater flow pattern tends to move from southeast to northwest, perpendicular to the tunnel’s direction. Groundwater quality testing indicates that water in the research area falls under the category of fresh groundwater, based on electrical conductivity and total dissolved solids values. The overall acidity level is generally acidic, except at specific points. In general, the interaction of groundwater with concrete results in weak erosion. It can be concluded that the groundwater at the research location is shallow, situated above the planned tunnel elevation, exhibits hydrochemical facies variations, and has the potential to weakly erode concrete.
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Yatini, Y., M. Faizal Zakaria, and Imam Suyanto. "Identification of Gold Mineralization Zones Using Magnetic Data at Gunung Gupit Area, Magelang, Central Java." RSF Conference Series: Engineering and Technology 1, no. 1 (2021): 305–12. http://dx.doi.org/10.31098/cset.v1i1.384.
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Indonesia is one of the biggest gold producing countries in the world. the discovery of new gold reserves makes the passion of the gold mining industry increase. The Gunung Gupit area of Magelang Regency in Central Java has discovered new gold potential, but has not been thoroughly explored. The magnetic method is applied to identify and determine the distribution of the presence of gold mineralized zones based on the magnetic properties of rocks. A total of 1001 points on 41 magnetic line were acquired using Proton Precession Magnetometer (PPM) Geometrics model G-856 in an area of 2.5 km2. Field data is obtained as Magnetic Field Anomaly. Reduction to pole (RTP) and low-pass filter process is applied to the magnetic anomaly. The results showed the Gunung Gupit area was divided into 4 zones based on magnetic anomaly responses, i.e strong, medium, weak anomaly and igneous rock zones. The 2.5 D modeling result shows the presence of northwest-southeast normal fault and strike slip fault that is perpendicular to the normal fault. These faults control the hydrothermal alteration in Gunung Gupit and its surroundings. A strong mineralization zone lies between these two faults. The presence of gold and other metal minerals lies in this strong mineralization zone, and moderate alteration. The coverage area is quite wide and distributed along the two faults.
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Kurniawan, Firman Heru, Margareta Rahayuningsih, Nugroho Edi Kartijono, and Muhammad Abdullah. "EVALUATION ON THE POPULATION OF STRANGLER FIGS (Ficus subgen. Urostigma) IN MOUNT UNGARAN, CENTRAL JAVA." Media Konservasi 27, no. 3 (2022): 83–90. http://dx.doi.org/10.29244/medkon.27.3.83-90.
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A group of the Ficus genus, the strangler figs (Ficus subgen, Urostigma), are known as a more potential as frugivores feed in Mount Ungaran. While the land clearance of the forest into monoculture plantation threats their existence. This study aims to evaluating strangler figs condition by the population study, i.e. densities, distribution, and the demography of each strangler fig species. A total of 25 ha area of Gentong Hill (Northwest part of Mount Ungaran) have been sampled during January-May 2018. We conducted a census of the figs within the sampled area and recorded their life stages in such area. As well as explain the current condition of host tree used by strangler figs in such area. Based on the census that have been conducted, 35 individual belongs to six species strangler figs that equal with 1.4 individual/ha in the value of density is recorded. F. kerkhovenii and the Javan endemic F. involucrata was the commonest species by their densities and abundance. Most of host tree were found dead. The remaining living host tree (16 individuals) are included in three species, i.e. Syzigium antisepticum (14 individual), Weinmannia fraxinea (1 individual), and Engelhardtia spicata (1 individual). Most of the strangler figs found was reached in stage 5 of their life demography, while the stage 1 was the rarest by only 1 individual found. The distribution of strangler figs showed a random pattern. Both of densities and distribution is reasoned by the availability of host tree.
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Pangestu, Dany, Ratih Suci Ramadhanti, and Ahmad Fadlan. "PEMETAAN POTENSI PEMUTIHAN KARANG DI PERAIRAN INDONESIA MENGGUNAKAN ANALISIS DATA SUHU PERMUKAAN LAUT." Prosiding SNFA (Seminar Nasional Fisika dan Aplikasinya) 3 (February 28, 2019): 65. http://dx.doi.org/10.20961/prosidingsnfa.v3i0.28512.
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<p class="AbstractEnglish"><strong>Abstract:</strong> Indonesia is the country that contributed the largest coral reefs, about 18% total of the entire the world. Area of coral reef in Indonesia known as the “Coral Triangle”. This ecosystem has high ecology and economic value. The existence of the coral reefs is the main attraction for a tourism destination. However, the function and role of these ecosystems are decreasing due to natural factors and artificial factors. One of the natural factors is due to the influence of global warmings, such as sea surface temperature (SST), causing damage and coral death, known as coral bleaching. The purpose of this study was to identify the potential for coral bleaching in Indonesian waters using SPL anomaly analysis obtained from monthly AVHRR POES in the morning and night. This research used hotspots data (HS) by calculating the average of data anomaly difference with a maximum monthly average data during 10 years (2006 - 2017). The results obtained show that areas that have the potential to become coral bleaching in Indonesian waters are quite varied. In general, it covers the northern coast of Banten, DKI Jakarta, West Java, Central Java, East Java, the northwest coast of Lampung, Pekanbaru, and Riau, the northwest coast of Papua Island, and North Natuna waters. The results also showed that sea surface temperatures in Indonesian waters were quite influential on coral bleaching.</p><p class="KeywordsEngish"><strong>Abstrak:</strong> Indonesia merupakan negara penyumbang terumbu karang terbesar yaitu 18% dari total dunia. Wilayah terumbu karang di Indonesia dikenal dengan wilayah “<em>Coral Triangle</em>”. Ekosistem ini memiliki nilai ekologis dan ekonomis yang tinggi. Keberadaanya merupakan daya tarik tersendiri untuk dijadikan lokasi wisata. Namun, fungsi dan peranan ekosistem ini menurun akibat faktor alam dan faktor buatan. Salah satu faktor alamnya diakibatkan pengaruh pemanasan global yaitu naiknya suhu permukaan laut (SPL) sehingga menyebabkan kerusakan dan kematian karang atau dikenal sebagai pemutihan karang. Tujuan penelitian ini adalah mengidentifikasi potensi terjadi pemutihan karang di wilayah perairan Indonesia menggunakan analisis anomali SPLyang diperoleh dari POES AVHRR pagi dan malam bulanan. Metode yang diugunakan mencari data hotspot (HS) dengan melakukan perhitungan rata rata selisih data anomali dengan data rata rata maksimum bulanan selama 10 tahun (2006 - 2017). Hasil yang didapat menunjukkan bahwa wilayah yang berpotensi menjadi pemutihan karang di perairan Indonesia cukup beravariasi. Secara umum meliputi meliputi pesisir utara dari Provinsi Banten, DKI Jakarta, Jawa Barat, Jawa Tengah, Jawa Timur, pesisir barat laut Lampung ,Pekanbaru dan Riau, pesisir barat laut dari Pulau Papua, dan perairan Natuna Utara. Hasil penelitian juga menunjukkan bahwa suhu permukaan laut di perairan Indonesia cukup mempengaruhi pemutihan karang<strong>.</strong></p>
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Widagdo, Asmoro, I. Gde Sukadana, and Frederikus Dian Indrastomo. "Geological Structure Control on the Formation of Metal Mineralization at Quartz Veins in Jendi Village, Wonogiri Regency, Central Java." EKSPLORIUM 43, no. 2 (2023): 89. http://dx.doi.org/10.17146/eksplorium.2022.43.2.6623.
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Quartz veins in the Jendi area and its surroundings are formed by geological structures with distributions and patterns that need to be known. This study uses data on striation, quartz vein orientation, and metal content in quartz veins. The use of this data aims to determine the relationship between the vein direction pattern and its metal mineral content with the main structure that forms it. The results of this study can be useful in determining the structural model and distribution of veins in the study area. The research method was carried out through a series of field and laboratory work. Fieldwork includes measuring striation data, measuring the orientation of quartz veins, and taking quartz vein samples. Studio work includes stereographic analysis of striation data, rosette diagram analysis of vein measurement data, and analysis of metallic element content of quartz veins. The quartz vein mineralization zone in the study area is controlled by a right slip fault with a northwest-southeast trend that forms a transtension zone with a north-south trend. The north-south trending veins are generally thick, long/continuous, and have a high metal content.
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Reza, Teuku, Lilik Eko Widodo, Irwan Iskandar, Rusmawan Suwarman, and Boy Yoseph CSSSA. "Physical Soil Parameter and Resistivity Profile in the Vadose Zone: Preliminary Result of Groundwater Recharge Study." BIO Web of Conferences 73 (2023): 05023. http://dx.doi.org/10.1051/bioconf/20237305023.
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In tropical-volcanic-dominated areas, such as Java Island in Indonesia, aquifer recharge is highly impacted by rainfall intensity and soil characteristics. The first stage of recharge begins with the soil surface's response to rainwater until it percolates to the deep layer. The primary objective of this research was to study groundwater recharge processes from the soil surface to deep percolation in the volcanic deposit at the northwest flank of Mount Pangrango, West Java, Indonesia. The present study also includes the 2D geoelectrical survey results combined with the soil core drilling. A vertical undisturbed soil profile 4 to 4.5 meters deep was drilled to determine parameters such as soil water content, total porosity, permeability, organic content, and soil texture. Results from core drilling activities confirmed that resistivity values are in the range of 80 to 360 ohm.m, which is related to wet soil layers at 1 to 4 meters below the surface. It is found that the most significant difference between organic and mineral soils in terms of resistivity value is that of organic content. Depth and radius of Pinus merkusii and Melia azedarach tree according to resistivity and soil drilling result confirmed at 2.5; 4.5 meter and 0.9; 2.2 meters respectively. By profiling these factors, the behavior of water movement may be better described, allowing the net recharge rate from rainwater to the water table in the unsaturated zone to be estimated.
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Indah, M. S., Abdul Haris, and M. Natsir. "Integrated of Sequences Seismic Stratigraphy, Accoustic Impedance Invertion, and Petrophysical for Resources Exploration in Offshore Southern Ardjuna Northwest Java Basin, Indonesia." IOP Conference Series: Materials Science and Engineering 546 (June 26, 2019): 072002. http://dx.doi.org/10.1088/1757-899x/546/7/072002.
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Mulyana, Erwin. "ANALISIS CUACA SELAMA KEGIATAN TMC REDISTRIBUSI CURAH HUJAN." Jurnal Sains & Teknologi Modifikasi Cuaca 14, no. 1 (2013): 13. http://dx.doi.org/10.29122/jstmc.v14i1.2677.
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IntisariPada tanggal 26 Januari sampai dengan 27 Februari 2013 telah dilaksanakan penerapan teknologi modifikasi cuaca (TMC) untuk redistribusi curah hujan di wilayah Jakarta dan sekitarnya. Selama kegiatan tersebut fenomena ENSO dan IOD dalam kondisi normal. MJO menunjukkan adanya peningkatan aktifitas konvektif di wilayah Indonesia pada pertengahan hingga akhir bulan Februari 2013. Temperatur permukaan laut di perairan sekitar Jawa bagian barat sekitar 29-300C. Kelembagan udara pada level 850 mb sekitar 75-80%. Pertumbuhan awan umumnya berada di sebelah barat laut hingga barat daya Jakarta.AbstractApplication of weather modification has carried out to redistribute of precpitiaion over Jakarta and the surrounding during 26 January to 27 February 2013. During this period, ENSO and IOD was normal condition. The MJO shows that the convection enhanched over Indonesia region on mid to late February 2013. The sea surface temperature over west part of Java waters was 29-300C. The 850 mb relative humidity on February 2013 was 75-80%. Cloud development mainly over northwest to southwest of Jakarta,
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Putra, I. Nyoman Januarta Triska, I. Wayan Gede Astawa Karang, and I. Dewa Nyoman Nurweda Putra. "Analisis Temporal Suhu Permukaan Laut di Perairan Indonesia Selama 32 Tahun (Era AVHRR)." Journal of Marine and Aquatic Sciences 5, no. 2 (2019): 234. http://dx.doi.org/10.24843/jmas.2019.v05.i02.p11.
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One of the important factor that influences global climate dynamics is sea surface temperature (SST). Indonesian waters are semi-closed and located between the Pacific and Indian Oceans so that they have different characteristics of SPL in each region. The purpose of this research is to know the trend and local characteristics of Indonesian SST and adjacent areas in response to 6-monthly and seasonal variability with moving average method and correlation. The data used are SST data from AVHRR satellite with domain 15°N-15°S, 90°-145° E. The results showed of increase trend 0.34°C in Indonesian sea for 32 years (1981-2012). The characteristics of SST in Indonesian territory are closely related to the Mosoon cycle where in the East period in the northern region the Natuna Sea is warmer in contrast to the West monsoon period, in the southern part of the Arafura Sea to the warmer Sawu Sea and around the equator experiencing the warmest in the transitional period. The moving-average analysis shows that 6-monthly variability appears to be dominated in equatorial waters including the Java Sea and Banda Sea whereas seasonal variability occurs in the northern and southern regions of Indonesia's waters including the Pacific Ocean Oceans, the northwest Pacific Ocean and the southeast Indian Ocean. Based on correlation analysis, ENSO has a strong (negative) relationship in eastern Indonesia waters including the Sea in the northern part of Papua and the northwest Pacific Ocean while IOD has a strong (negative) relationship in the western Sumatra Sea, Banda Sea and Arafura Sea.
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Nurhasan, Muhammad Nadhif Rizqia, Hidayat, et al. "Identification of Geological Structure Based on Gravity Method in Tangkuban Parahu Volcano, Bandung, Indonesia." IOP Conference Series: Earth and Environmental Science 1159, no. 1 (2023): 012006. http://dx.doi.org/10.1088/1755-1315/1159/1/012006.
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Abstract Tangkuban Parahu Volcano, located in Cikahuripan, Lembang, West Bandung Regency, West Java, Indonesia, has a geothermal potential. However, this potential is accompanied by geohazard risks, one of which is a volcanic eruption that can interfere with the development of geothermal potential. On February 12, 2022, there was a gust of volcanic gas from Ratu Crater, indicating an increase in volcanic activity after an eruption in 2019. Based on the geological map of Tangkuban Parahu/Sunda Volcano Complex, it is estimated that there is a fault structure in a northwest-southeast direction, where if a volcanic eruption occurs, it will cause greater deformation because it cuts through Ratu Crater. Further studies with geophysical methods are needed to estimate the fault structure. The study of the subsurface geological structure of Tangkuban Parahu Volcano was carried out using the gravity method by studying variations in the gravitational field on the earth’s surface to determine differences in rock density. The Complete Bouguer Anomaly (CBA) value from the gravity method at Tangkuban Parahu Volcano shows 68 – 73 mGal, and residual anomaly values ranged from -0.95 to 0.67 mGal. The negative residual anomaly value between -0.95 to 0 mGal shows the weak zone due to volcanism in the crater. On the other hand, high residual anomaly values ranging from 0 to 0.67 mGal are interpreted as the influence of Lava 1 Tangkuban Parahu (Tl1). Analysis using First Horizontal Derivative (FHD) and Second Vertical Derivative (SVD) shows a fault structure trending Northwest – Southeast, which can be a way out of the accumulation of high-pressure water vapor due to volcanic activity.