bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of internal oscillations in a dynamic system through an external signal implemented in circadian rhythms
Authors: Mesa F , González-Granada J R , Correa-Vélez G
Published: November 2021

Through the analysis carried out on a dynamic model that is represented as a system of ordinary differential equations that describes the behavior of the circadian cycles; we will show and analyze in the next document what are the conditions that allow the synchronization of the circadian clock oscillator with the external modification oscillator. The implementation of this type of techniques in anatomical problems is highlighted, which are rare in the literature. The implementations will be carried out through different simulations using numerical techniques and the way in which we will determine the coupling conditions of an internal cycle of the system versus external cycles will be detailed. In the final development of this work, we will be able to see in the model without an external modification signal the existence of stable limit cycles and discover the moment in which the synchronization of the internal oscillator and the external modification signal occurs. These types of problems are common when making biological models that are described by a physical analysis.
Applications of thermodynamics to study the physical phenomenon of heat conduction
Authors: Nolasco Serna C , Afanador García N , Gómez Camperos J A
Published: November 2021

Thermodynamics can be understood as the discipline of the physical sciences, that studies theoretically and practically the different manifestations of energy. The study of thermodynamics is important in relation to the understanding of thermal systems in industry, as well as, supporting energetic processes in living organisms. In relation to the study of energy processes in the context of heat transfer, concepts from thermodynamics are relevant. In the present investigation, the process of heat conduction in a metal bar is analyzed by applying the heat equation and the concept of entropy variation. The first part of the research proposes a numerical method to solve the heat equation in addition to a set of finite difference equations describing the energetic behavior of the system. The numerical solution of the heat equation and the thermodynamic behavior of the system are studied by programming to demonstrate the fit of the results with the theoretical models. Finally, applications of the achieved results in engineering contexts are discussed.
Development of an electro-pneumatic system for the practical training of pneumatic processes in the university environment
Authors: Rojas Suárez J P , Pabón León J A , Orjuela Abril M S
Published: November 2021

This article describes the implementation of an electro-pneumatic test bench, which allows the availability of a physical environment to promote learning. The aim of the paper is to create a tool that enables practical training and research of pneumatic processes for university students in the field of engineering. The control and automation system of the test bench is made up of wired logic panels, timers, and programmable logic controllers, which are integrated into a control board configured at 24 V (direct current) to guarantee safety. Additionally, ergonomic principles were considered for the construction of the electro-pneumatic bench, thus favoring the accessibility and safety of the users. Based on national and international regulations, working pressure of 9 bar and an approximate pressure drop of 0.07 bar were defined. The construction of the test bench is considered an educational strategy to facilitate and accelerate the learning process of the students. Additionally, the development of the electro-pneumatic bench allowed the dynamic characterization of double-acting actuators by integrating experimental data and numerical models. This allowed the detailed analysis of the displacement, velocity, and acceleration variables in this type of actuator, which contributes to the physical study of pneumatic systems.
On the abundance of supersymmetric strings in AdS3 × S
3 × S
3 × S
1 describing BPS line operators
Authors: Correa Diego H. , Giraldo-Rivera Victor I. , Lagares Martín
Published: November 2021

We study supersymmetric open strings in type IIB AdS3 × S
3 × S
3 × S
1 with mixed R–R and NS–NS fields. We focus on strings ending along a straight line at the boundary of AdS3, which can be interpreted as line operators in a dual CFT2. We study both classical configurations and quadratic fluctuations around them. We find that strings sitting at a fixed point in S
3 × S
3 × S
1, i.e. satisfying Dirichlet boundary conditions, are 1/2 BPS. We also show that strings sitting at different points of certain submanifolds of S
3 × S
3 × S
1 can still share some fraction of the supersymmetry. This allows to define supersymmetric smeared configurations by the superposition of them, which range from 1/2 BPS to 1/8 BPS. In addition to the smeared configurations, there are as well 1/4 BPS and 1/8 BPS strings satisfying Neumann boundary conditions. All these supersymmetric strings are shown to be connected by a network of interpolating BPS boundary conditions. Our study reveals the existence of a rich moduli of supersymmetric open string configurations, for which the appearance of massless fermionic fields in the spectrum of quadratic fluctuations is crucial.
Network of Radon Gas Concentration Monitoring of Research and Development Centre – BMKG for Earthquake Precursor Research in Indonesia
Authors: Martha Agustya Adi , Prayogo Angga Setiyo , Nugraha Jimmi , Pakpahan Suliyanti , Riama Nelly Florida
Published: November 2021

The geographical position of Indonesia, which is flanked by several subduction zones and the presence of active faults in the sea and land make Indonesian territory prone to earthquakes and tsunamis which can result in many deaths and damaged. There are several efforts we can do to minimize the occurrence of earthquakes, including developing earthquake resistant buildings, increasing the ability/capacity of the community, and predicting earthquakes or better known as earthquake precursors. The BMKG Research Centre began conducting research on earthquake prediction using several methods, including the Radon monitoring method. Monitoring of Radon gas concentrations for earthquake precursors has several advantages, including the presence of radioactive gas which is abundant in ground water that has a half-life of 3.2 days. Radon is the result of decay of uranium 278U which is abundant in the earth’s crust rock so that when rock friction occurs, the Radon gas can be detached. Based on the results of Radon monitoring at Tadulako and Palolo stations - Southeast Sulawesi province, there was a change in the pattern of radon gas concentration and water level rising up and down drastically and a gradual decrease in ground water temperature before the earthquake on 28 September 2018. In addition to Central Sulawesi, since 2012 the Centre for Research and Development of BMKG has been conducting research to monitor radon gas concentrations in the DI Yogyakarta region precisely in Piyungan and Pundong districts with the aim of monitoring radon gas concentrations in the Opak fault. In 2021, the BMKG Research and Development Centre added a new radon gas monitoring network in the active fault areas of Cimandiri and Lembang in the West Java province. There are 1 station in the Cimandiri fault segment and 2 stations in the Lembang fault section. It is hoped that in the future the results of monitoring can reduce the impact caused by the earthquake disaster in Indonesia.
Determination of Hypocenter Using Geiger Method in Sinabung Volcano, April-July 2016 Period
Authors: Annisa Y , Astriyan G C , Wahyunia S , Indrastuti N , Massinai M F I
Published: November 2021

Sinabung is a volcano located in the Karo Highlands, Karo District, North Sumatra, Indonesia, with the highest peak of 2460 meters mean sea level. Volcanic earthquake is an earthquake that occurs due to volcanic activity. This is caused by the movement of magma upwards in the volcano. This study aims to determine the type of earthquake, hypocenter position and epicenter of volcanic earthquakes in Sinabung volcano in April-July 2016. The principle of this study was carried out by analyzing volcanic earthquake data in Sinabung volcano in April-July 2016. The data is recorded data (seismogram) or in other words is secondary data from Sinabung volcano on 7 seismometer stations namely Sukanalu, Lau Kawar, Sigarang-Garang, Mardinding, Gamber, Sibayak, and Kebayaken stations. Earthquake data in April-July 2016 revealed that there were 24 earthquake events in a period of 3 months which were the results of picking up the P and S waves, where volcanic earthquakes were obtained only in the form of volcanic earthquake type A and type B volcanic earthquake. Sinabung volcano has an earthquake activity that high enough so that the status of Sinabung volcano is still at level III (standby) status. Based on the hypocenter of several VA and VB earthquakes that occurred in April-July 2016, it can be concluded that the distribution of the hypocenter of the volcanic earthquake shows that the maximum depth of the volcanic earthquake is 10.000 meters and the position of the earthquake is spread at the point between Sinabung volcano and Mount Sibayak.
Preliminary study of stress changes evolution on central part of Sumatran Fault influenced by large interplate earthquakes and tectonic stress rates
Authors: Rafie Muhammad Taufiq , Cummins Phil R , Sahara David P , Widiyantoro Sri , Triyoso Wahyu , Nugraha Andri Dian
Published: November 2021

The inland seismic activity in Great Sumatran Fault (GSF) has significantly increased over the past several decades after the occurrence of historical large interplate earthquakes along the plate boundary. This condition led to some occurrences of historical intraplate earthquakes along Sumatran fault. To quantitatively examine the physical mechanisms between intraplate earthquakes and interplate earthquakes, we estimated the static coseismic stress changes of Coulomb failure function (ΔCFF) using receiver fault approach from large historical-recorded interplate earthquakes and the increase in tectonic stress rates. We examined this research in the central part of GSF since this zone is assumed to have the most heterogeneous stress field and thus became our focus study area. The cumulative ΔCFF models showed almost all segments in the central part of GSF suffered negative changes (<-0.1 MPa) which assumed to be unlikely to rupture in short time. However, the preliminary analysis of the increase in tectonic stress rate indicated that large intraplate earthquakes occurred on Angkola and Siulak segments were dominantly influenced by the increase in interseismic stress rate just after the series of large subduction earthquake occurrences, apart from the decreased stress changes from those major interplate earthquakes.
Potential Eruption and Current Activity of Anak Krakatau Volcano, Indonesia
Authors: Kristianto  , Indrastuti N , Basuki A , Purnamasari H D , Adi S , Patria C , Haerani N
Published: November 2021

Anak Krakatau Volcano is located in the Sunda Strait known for its paroxysmal eruption in 1883. During the January - November 2019 period, seismicity was dominated by types of quakes which indicated the occurrence of magma supply (VA and VB), near-surface volcanic activity (LF, Hybrid, Harmonic Tremors), and volcanic activity above the volcanic surface (eruptions, emission, and continuous tremors). In the period December 2019 - July 2020, there was an increase in the types of quakes near the surface (LF, Hybrid) and the types of quakes on the surface (emission and continuous tremors). Volcanic deformation monitors changes in tilt over the 2019-2020 period associated with pressure releases before, during and after the eruption. The results of GPS data modeling, the shallow pressure source is at a depth of 0.22 km below sea level. Volcanic activity until July 2020 was dominated by activity near and above the volcanic surface associated with the growth of lava domes. The volcanic system of Anak Krakatau is currently an open system, with the potential for eruptions. Strengthening the early warning system for the eruption of Anak Krakatau is important in mitigating efforts and understanding its eruption potential
Slip distribution effect in spatial coulomb stress analysis (Case study: Palu earthquake on September 28, 2018)
Authors: Clinton Wulur Kevin Hanyu , Suardi Iman , Dwi Sriyanto Sesar Prabu , Perdana Yusuf Hadi
Published: November 2021

On September 28, 2018, the Palu-Koro fault released the accumulated stress that caused the earthquake. An earthquake with magnitude 7.5 caused large and massive damage around Palu. There were many aftershocks along the Palu-Koro fault. This research aims to calculate a model of spatial Coulomb stress based on this event to find a correlation between mainshock and the aftershocks. The slip distribution was used as an input of the spatial stress Coulomb modeling to increase the accuracy. We use the Teleseismic Body-Wave Inversion method to calculate slip distribution along the fault plane. As a result, this earthquake was generated by the Palu-Koro fault movement with Mw 7.48, strike 350°, dip angle 67°, and rake -9°. There are three asperity zones along the fault plane located in the north and southern parts of the fault plane. The location of the most energy discharge is in the south asperity zone of the fault plane model with a maximum slip value of 1.65 meters. The spatial Coulomb stress change of this event shows that aftershocks concentration are in areas experiencing increased stress after the earthquake.
The Use of Core & Log Anisotropy Parameters into Seismic Data Processing: A Case Study of Deep-Water Reservoir
Authors: Oktariena Madaniya , Triyoso Wahyu , Ambarsari Dona Sita , Sukmono Sigit , Septama Erlangga , Wardaya Pongga D , Murdianto Befriko S , Raguwanti Rusalida , Pratama Richie R
Published: November 2021

The seismic far-offset data plays important role in seismic subsurface imaging and reservoir parameters derivation, however, it is often distorted by the hockey stick effect due to improper correction of the Vertical Transverse Isotropy (VTI) during the seismic velocity analysis. The anisotropy parameter η is needed to properly correct the VTI effect. The anisotropy parameters of ε and δ obtained from log and core measurements, can be used to estimate the η values, however, the upscaling effects due to the different frequencies of the wave sources used in the measurements must be carefully taken into account. The objective is to get better understanding on the proper uses of anisotropy parameters in the the velocity analysis of deepwater seismic gather data. To achieve the objective, the anisotropy parameters from ultrasonic core measurements and dipole sonic log were used to model the seismic CDP gathers. The upscaling effects is reflected by the big difference of measured anisotropy values, in which the core measurement value is about 40 times higher than the log measurement value. The CDP gathers modelling results show that, due to the upscaling effect, the log and core-based models show significant differences of far-offset amplitude and hockey sticks responses. The differences can be minimized by scaling-down the log anisotropy values to core anisotropy values by using equations established from core – log anisotropy values cross-plot. The study emphasizes the importances of integrating anisotropy parameters from core and log data to minimize the upscaling effect to get the best η for the VTI correction in seismic velocity analysis.
River sedimentation modeling using ground-penetrating radar
Authors: Firdaus M A , Widodo  , Fatkhan
Published: November 2021

In recent years, siltation has become quite a problem. It has been the main cause of flooding and a rapid decline in water quality. It is usually caused by a high river sedimentation rate and/or uncontrolled waste disposal. The increased rate of erosion also means that river sedimentation occurs faster than normal and could lead to environmental hazards, wildlife deaths, and the disruption of food and drinking water supply among other things. The question is how to monitor the sedimentation process of rivers without damaging the river itself. The suitable geophysical method is GPR. GPR is an active, non-intrusive geophysical method in which electromagnetic radiation and the reflected signals in the form of radar pulses are used for subsurface imaging. The objective is to investigate river sedimentation using GPR, we created the synthetic models based on geological models of rivers with different depths to create their 2-D radargrams to predict the actual model. We set up the first model RSM-I as control which consists of a layer of freshwater with ρ = 16 Ωm, k = 81 and μ
r = 1 of depth 5 m, two layers of sandstone with ρ = 850 Ωm, k = 2.5 and μ
r = 1 of total depth 4 m, and a layer of claystone with ρ = 120 Ωm, k = 11 and μ
r = 1 of depth 1 m. RSM-II and III are added with a buildup of saturated sediment with ρ = 30 Ωm, k = 15, and μ
r = 1 of depth 2.5 and 4 m, respectively. The radargrams’ reflector for each model shows a two-way travel time of 300-350, 150-200, and 60-90 ns in their respective order. GPR models can differentiate between the saturated sediment and freshwater, it shows good results regarding sediment investigation in rivers.
Identification of Ransiki fault segment in South Manokwari Regency, West Papua Province, Indonesia based on analysis of a high-resolution of global gravity field: Implications on the Earthquake Source Parameters
Authors: Lewerissa Richard , Alzair Nur , Lapono Laura
Published: November 2021

The province of West Papua in Indonesia is an area crossed by three major faults, including Sorong, Koor, and Ransiki, leading to the collision of Australia, the Pacific, and Eurasia. In the past, there have been strong and damaging earthquakes on these faults, manly Ransiki fault in the South Manokwari regency. Identification of the Ransiki fault segment was conducted by geological subsurface modeling using the earth gravity field of the Global Gravity Map (GGM) based on satellite measurements implicates for earthquake source parameters. The GGM is seen as a solution for the unavailability of direct measurements in the region. The gravity field analysis begins with data reduction using SRTM2gravity as modern terrain correction to obtain a complete Bouguer anomaly. Furthermore, the gravity gradient approach through vertical and horizontal gradients, analytical signal, and the tilt angle are applied to emphasize a contact or fault structures that are not visible using a 2D fast Fourier transform. Overall, the gravity gradient analysis obtained results that were compatible with the alignment of the Ransiki fault segment which direction of the northwest to south. The gravity inversion produces a geological subsurface model that clearly shows the Ransiki fault segment, associated with a low rock density distribution, thought to the Befoor formation and quaternary sediments, located between high-density rocks correlated to Arfak volcanic rocks as a basement.
Seismic reservoir characterization of gas-sand deposits in the Kutei basin, Indonesia
Authors: Iqbal M , Ambarsari D S , Sukmono S , Triyoso W , Sanny T A , Septama E , Wardaya P D , Pratama R R , Murdianto B S , Raguwanti R
Published: November 2021

Kutei Basin has the second largest hydrocarbon reserve in Indonesia. In addition to the Miocene inversion related structural traps, slope-fan and channel stratigraphic traps are also important traps in this basin. To guide stratigraphic traps explorations in the basin, the seismic stratigraphy, attributes, and AI inversion methods are integrated to identify and map the reservoir seismic facies, porosity, and pore-fluid. Well data indicates that the studied reservoirs are filled by gas. Seismic data shows that there are two main gas-sand reservoirs corresponding to strong amplitude anomaly. Seismic stratigraphy analysis, guided by seismic attributes, shows that these gas-sand reservoirs were deposited in the channel and local fan facies. The AI inversion is applied to identify and map the porosity and pore-fluid of these two sand reservoirs. Future well locations are identified by integrating the facies, porosity, and pore-fluid maps.
Two earthquake events on the Pamsoa Segment of the Matano Fault, Sulawesi
Authors: Daryono Mudrik Rahmawan , Kumarawarman Budhi , Muslim Irpan Hidaya , Triwurjani Rr. , Permadi Reza , Prihatmoko Sukmandaru , Wibowo Setiyo , Tutuko Gde Handojo
Published: November 2021

Sulawesi Island crossed by the importance active faults of the Palukoro Fault in the western part and the Matano Fault in the eastern part. Pamsoa Segment, the fourth of six-segments of the Matano Fault (from west to east), located near importance Sorowako mining city, Sulawesi. Pamsoa segment has a 38 km length, oriented N295°E, and has an obvious 475 m sinistral river offset. A reconnaissance survey conduct in this segment along the fault crosses the mining dirt road. Two fault rupture existed on the Holocene river terrace. Accelerated Mass Spectrometry (AMS) carbon dating shows age about 5218 BP and 4446 BP on the soil samples. Nice slicken-side on red soil shows as a fresh fault rupture. This rupture shows a possible two earthquake event on the Pamsoa Segment. The Matano fault has potency similar to the 2018 Palu earthquake. If the fault has similar multi fault rupture earthquake characteristic, the Matano Fault is also classified as a Magnitude 7+ class earthquake. Further research is needed to get precise earthquake geology parameters and ideal charcoal samples.
Investigation of Rawa Dano Volcanic Deposits and Its Paleotopography Using Ground-Penetrating Radar
Authors: Maryadi Maryadi , Sausan Champai Fira Mariah , Nyoman Triananda I , Darmawan Andi , Jabbar Gamma Abdul
Published: November 2021

The detailed mechanisms of volcanic eruptions happened around Rawa Dano, Banten, Indonesia, remain undiscovered. One of the key features to this geological event is the presence of a 13.7 km × 6.5 km caldera-like morphology in the middle of Banten tuff deposits. Surface geological investigation in the area indicates that the eruptions are massive and occurred in several periods. Low-frequency ground-penetrating radar (GPR) signals are used as an aid to identify the unexposed part of the deposits in this volcanological study. Common-offset GPR surveys were carried out along three measurement lines traversing over the deposit outcrops. An outcrop which is exposed after sand mining activities at one of the survey locations shows dipping interfaces between the upper pyroclastic flow deposits, pumice-rich deposits, paleosol, and the lower pyroclastic fall deposits. These stratigraphic contacts are detected as well under the surface which are clearly recognizable in radar images. The GPR cross-section also shows some other reflections due to different deposit types. The overall results of the GPR profiles give the idea about the thickness of each type of volcanic deposits and the paleotopography in the surrounding area.
Potentially active normal faulting zone identified in the eastern margin of Palu City, Central Sulawesi, Indonesia
Authors: Puji Anggraini Rizkita , Daryono Mudrik Rahmawan , Natawidjaja Danny Hilman
Published: November 2021

The 2018 Mw 7.5 earthquake in Palu, Central Sulawesi, resulting in ~2,000 fatalities and estimated economic losses of ~22.8 trillion Indonesian Rupiah, according to the report of BAPPENAS and Central Sulawesi Provincial-Government. Therefore, it is necessary to prevent similar disaster in the future by further detailed studies of any other potential sources that are capable of generating such hazards. Palu City is in the vast depression valley bordered by mountains in its eastern and western margins. The 2018 earthquake source is the Palukoro Fault, which runs through the western margin of onshore Palu Valley then continued under the bay. Along the eastern margin of the valley, we also identified a wide zone of many potentially active faults strands orienting N-S and NW-SE, showing predominantly normal faulting. These faults are observed from their normal fault scarps as inspected from Light Detection and Ranging Digital Terrain Model (LiDAR DTM) data with 90-cm resolution and field ground checks. The faults deformed the old terrace sediments (Late Pleistocene, ~125 kya), but it is unclear whether they also cut the Holocene young alluvial like the ruptured fault of 2018 event. Further paleoseismology investigation is then necessary to obtain further information about these potentially-active normal faults, including their slip-rate and the past ruptures.
Seismicity around Cirata Dam, West Java, Indonesia based on BMKG local seismic network
Authors: Priyobudi  , Ramdhan M , Daryono
Published: November 2021

The addition of seismic stations to the seismic network of BMKG in 2019 has successfully located some local earthquakes. In the early 2020 occurred significant earthquakes around Cirata Dam, West Java. During a period of January-March 2020, there have been 5 earthquakes with magnitude ranging from 1.8-3.7. Those earthquakes caused ground shaking up to III MMI intensity scale around the epicenters area. The relocation of the hypocenter using the Teletomo-DD method is applied in this study so that the data can be interpreted to show the fault geometry in this area. The relocated epicenters distribute in the east side of the dam elongated in SSW-NNE direction. Vertical distribution of relocated hypocenters show that the earthquake occurred at 1.1 km down to 14.5 km depth. Hypocenter depths are getting deeper to the north direction, this suggest dip orientation of the fault plane. The reconstructed dip orientation is consistent with nodal plane resulted from moment tensor inversion results, that shown fault planes oriented in N 2290–2720E direction and dip 490–500to the north direction.
MAGNETIC AND GEOCHEMICAL CHARACTERIZATIONS OF IRONSAND DEPOSITS FROM CIREBON COASTAL AREA, WEST JAVA
Authors: Nathasa R , Bijaksana S , Fajar S J , Pitaloka T G
Published: November 2021

Cirebon is a densely populated port city which has ironsand deposits at its coastal area. Due to its vicinity to the port and the estuary, these deposits might contain anthropogenic pollutants including, heavy metals. Magnetic measurements, X-Ray diffraction (XRD) as well as X-Ray fluorescence (XRF) analyses were carried out on iron sand samples from three sites along the Cirebon coastal area to identify the anthropogenic pollutants. The samples were separated based on the grain size before the measurement and analyses. Preliminary results show that the ironsand is less magnetic and has smaller frequency-dependent magnetic susceptibility values than ironsand found on Bayuran Beach in Central Java. Combined XRD result and the regional geological map shows that most of the minerals were originated from eroded volcanic rocks. The XRF results show that the samples have a relatively high content of Si. XRF analyses also show relatively high concentrations of Cr and Zn, the Geoaccumulation Index shows that the sediment is moderately to heavily polluted by Cr and Zn indicating the possibility of anthropogenic origin. The Cr and Zn content exceeds the stipulated value in the Sediment Quality Guidelines (SQGS).
Integrating Ground Penetrating Radar, Induced Polarization and Aerial Photograph to Analyze Land Subsidence in Borehole Mining Operation Area: A Case Study from South Bangka Island
Authors: Antonio Timothy , Parnadi Wahyudi W , Heriawan Mohammad Nur
Published: November 2021

The remaining alluvial tin reserves around large ex-mining area can be an opportunity to optimize the potential reserves using a small-scale mining system. One of the latest breakthroughs in the mining system for the remaining alluvial tin reserves on land is the borehole mining (BHM) method. However, mining operations using BHM have several environmental impacts especially related to its former holes. This study aims to identify the changes in geometry of the former holes both on the surface and below the surface through direct field observations and measurements using geophysical methods. The study site is in the large ex-mining area of Air Nudur Block in South Bangka Regency, Bangka Belitung Islands Province. The geophysical methods used to identify the changes in the geometry of the BHM holes are GPR (ground penetrating radar) and IP (induced polarization). The GPR method has high resolution subsurface visual capabilities at shallow depths and this method can distinguish between stable and unstable layers. The IP method is used to determine the overburden layer and the condition of the alluvial layer where some of it has become a hole. These two methods will mutually reinforce in interpreting the change in the geometry of the BHM holes. Changes in hole diameter and depth were measured directly in the field within 2 (two) months from the completion of mining operations using the BHM method followed by the periodic topographic measurements using UAV (unmanned aerial vehicle). The results of observations on changes in the elevation of the ground surface around the former BHM hole indicated that the land level subsided by about 1 m. Meanwhile, the results of GPR data processing showed changes in the hole geometry with the hummocky radargram pattern into chaotic. Interpretation of IP data processing shows resistivity values of 250 - 1700 ohm.m and chargeability of 15 - 25 ms in the disturbed alluvial layer around the former BHM holes.
Landslide Susceptibility Zonation of Rongga District and Surrounding Areas Using Weight of Evidence (WoE) Method
Authors: Sadisun Imam A. , Prasaja Dika B. , Kartiko Rendy D. , Dinata Indra A.
Published: November 2021

Rongga District is located on West Bandung Regency, West Java, which is prone to landslide disaster. Morphological conditions in the form of steep hills become the one of landslide controlling factors. There are many landslide occurrences happen in this area, such as Nyomplong, Cibitung Village on March 23, 2020. The incident was triggered by heavy rain and strong winds. This area was chosen to assess the landslide susceptibility using the Weight of Evidence (WoE) Method. WoE is probabilistic bivariate method which connecting parameters causes landslide against distribution of landslide in research area. Landslide data which generated from direct observation in the field and satellite imagery morphology are 572 landslide events. The data is divided into two groups, the analysis data set (70%) and the validation data set (30%). The parameters used in the analysis are land use, slope, slope direction, curvature, elevation, rainfall, lithology, NDWI, NDVI, distance from road, distance from the river, distance to lineament, flow direction, lineament density, stream density and river density. The parameters validated by determining the value of the area under curve (AUC). AUC value> 0.6 will be used in the landslide susceptibility zonation next analysis. Validation of landslide susceptibility zonation was carried out using 172 landslide events. The result of the WoE validation shows the AUC success rate of 0.70 and AUC prediction rate of 0.76. The value of AUC shows that the modelling is good and acceptable.
Preliminary Study: Identifying the Heat Source of Hot spring Discovery at Non-Volcanic Region with Gravity Method
Authors: Mawalid Abi , Mardhotilla Andi
Published: November 2021

Gravity method is one of the geophysical methods that’s using variation of gravity value caused by density variation of subsurface. Gravity method has been utilized for many purposes such as understanding the geological information about one area or understanding the subsurface structure. This study is using gravity method to identify the heat source from the geothermal manifestation (hot spring) which is located in the non-volcanic region in North Java. Gravity data was obtained from WGM 2012 satellite data that can be downloaded at BGI website and processed using Oasis Montaj software. Data processed using horizontal derivative method to enhance the boundaries resolution of the possibility geological structures location in the study area that is predicted to be the way of the heat source of hot spring manifestation. The result of this study shows that the heat source of the hot spring in Northern East Java is probably coming from Lasem Volcano’s heat source. The result can be proven by the similarity of the Bouguer Anomalies value between the Lasem Volcano region and the manifestations distribution area, which varies in 174-185 mGal. Besides that, Lasem Volcano is the closest volcano from the manifestation with a distance of approximately around 27 km.
Elastic and Viscoelastic Models of Crust Deformation in Strike-slip Fault
Authors: Bening Maulidia Ain , Sahara David P. , Kusumawati Dian , Triyoso Wahyu , Widiyantoro Sri , Nugraha Andri Dian
Published: November 2021

The crust, when viewed over a long period, moves towards one another. Crusts might experience sudden slip on a fault plane and caused fractures or cracks. There are three different types of faults, normal, reverse, and strike-slip faults. Induced stress due to sudden rupture on fault planes capable of creating stress and need to be measured quantitatively to comprehend the earthquake process. To understand the stress that occurs in strike-slip faults in the earth’s crust, the previous researchers study the use of elastic materials as the material of the earth’s crust, so that the earth crust’s deformation is elastic. However, elastic material has linear stress and strain relationship that results in reversible deformations or returns to their original shape. This material is not suitable for modeling the earth’s crust’s long-term deformation, where the deformation of the earth’s crust can be permanent, so a model is needed to solve this problem. In this study, we will compare the stress in the strike-slip fault in the upper crust with elastic materials, while the lower crust and upper mantle have viscoelastic materials compared to purely elastic materials through numerical simulations. This comparison is made to see the comparison between the two approaches with the earth’s layers’ actual state. The two models is chosen to represent the different failure processes of the earth crust, i.e. the elastic deformation part describes the response to stress in a short period, and the viscous deformation can explain the response over a more extended period. The study of both materials above is based on plate tectonic theory, in which the lithosphere plates will relatively move to each other because the layer material underneath is solid but can flow like a liquid for a long period.
Analysis of Hypocenter Relocation by Using Double Difference Method in a Deep Underground Mining
Authors: Hidayat Wahyu , Sahara David P. , Widiyantoro Sri , Putu Raditya Ambara Putra I , Shihab Nabiel H. , Amalia Rizka , Harisandi Azhar , Suharsono
Published: November 2021

Hypocenter relocation is one of the keys to success in the analysis of seismicity induction in underground mines. Overburden thickness, topography, geological complexity, and mining activities can result in newly induced seismicity that can endanger the safety of underground mine workers. The relatively narrow underground mine area requires the most accurate hypocenter location information possible. The double-difference algorithm approach is one of the keys to overcoming this problem. The double-difference method is a relative location method that tries to minimize the residuals between the observed and calculated travel time differences for pairs of microseismic events at each station, by adjusting the differences between all pairs of events at each station repeatedly. In this study, we utilized microseismic measurement data in the deepest underground mine in Indonesia. A total of 1783 seismic events were successfully relocated. The relocation results show the rock mass stress which is illustrated by the distribution of events around the cave, especially the abutment area and underground mining tunnels.
Maluku Sea Plate Faulting Regime Analysis: A Preliminary Study
Authors: Adii Jonathan , Kusumawati Dian , Falevi Cevian , Sahara David P
Published: November 2021

Present day Molucca or Maluku sea plate in the eastern of Indonesia possesses a complex tectonic setting. This complex tectonic setting has been formed due to the collision of an actively moving Eurasian plate and Philippine sea plate toward the Maluku sea plate. At the west, Maluku sea plate is subducting beneath Sangihe arc, which began in the early Miocene. While at the east, Maluku sea plate is subducting under Halmahera arc, since in the middle Miocene. These subduction processes take place up to the present. Therefore, it has formed Maluku sea plate into an inverted U-shape slab under a thickening accretionary complex. Seismicity distribution has clearly shown the U-shape slab. Earthquake events take place on the subducting slab, and interestingly on the above accretionary complex as well. Maluku sea plate might pose hazards to surrounding islands: northern Sulawesi, Halmahera island, Sangihe island and Talaud island. The possible hazard, for instance, a thrusting earthquake which may generate tsunami to the nearby islands. Hence, understanding its tectonic and seismicity signature, especially at the shallow part, are indeed important in the Maluku sea region. Faulting regime could be analyzed using focal mechanism ternary diagram analysis, by categorizing the focal mechanisms’ strike, dip and rake values. Thus, in this study we aim to analyze faulting regime and hazard potential in the complex. Maluku setting using ternary diagram analysis.
Determination of Shear Wave Splitting Parameters in 2018 Lombok Earthquake Using Rotation Correlation Method: Preliminary Result
Authors: Sasmi Annisa Trisnia , Nugraha Andri Dian , Muzli Muzli , Widiyantoro Sri , Zulfakriza Zulfakriza , Wei Shengji , Sahara David P , Puspito Nanang T , Priyono Awali , Afif Haunan , Supendi Pepen , Daryono Daryono , Ardianto Ardianto , Syahbana Devy Kamil , Husni Yayan Mi’rojul , Prabowo Billy S , Palgunadi Kadek Hendrawan , Narotama Sarjan Achmad Fajar
Published: November 2021

Shear-wave splitting (SWS), or the propagation of two independent shear waves, can be used as an indicator of seismic anisotropy. In this study, we utilize this concept using aftershock data of the 2018 Lombok earthquake which had been acquired in period of August 4 – September 9, 2018. The goal of this research is to better understand the crack distribution related to the rupture zone of the 2018 Lombok earthquake. After applying instrument correction to the data, the waveform data were then windowed in each P and S arrival time. To determine the SWS parameters, we performed rotation in each horizontal seismogram components. The horizontal components were rotated from azimuth 0° to 180° with an increment of 1°. Cross-correlation coefficient (CCC) was determined for each rotation angle. The polarization direction and the SWS delay time were chosen from the parameters shown in the highest value of CCC.
Landscape planning of historical tourism route of Siak Sultanate in Siak Sri Indrapura, Riau
Authors: Islami M Z , Nurhayati  , Gunawan A
Published: November 2021

Siak Sri Indrapura City designates as the National Cultural Heritage regarding the Siak Sultanate Historic Area (1723-1945). Some heritages of Siak Sultanate have become historical tourism objects, but they cannot yet convey the Siak Sultanate history. Therefore, the historical tourism route plan is needed. This study aims to identify the use of historical landscapes in Siak Sri Indrapura; identifying historical tourism objects; analyze the potential of historical tourist objects, and; create a landscape plan for the historical tourism route of the Siak Sultanate. The analysis used in this study is the significance value of the historical landscape to assess the originality and uniqueness of the historic landscape, spatial analysis to obtain suitable land for historical tourism areas, and descriptive analysis to assess other aspects of the history of the Siak Sultanate. Part of the historical landscapes in Siak Sri Indrapura have become historical tourism areas, and there are 27 Siak Sultanate heritages found during the survey. Based on the analysis result, all the heritages and Siak Sri Indrapura areas are suitable to be developed into historical tourism areas. This research's output is the historical tourism route map and the estimated historical tourism activity table in the Siak Sultanate. The Siak Sultanate tourism area divides into four: The Beginning of Siak Sultanate, The Sultan's and Datuk Tomb, The Palace, and The Colonial. The separation of the area based on location considerations and historical links between historical sites. With the historical tourism route plan, tourists can quickly learn and understand each Siak Sultanate heritage objects' historical linkages.
Park users’ perception and preference of public park in Bogor City post Large Scale Social Restriction (LSSR)
Authors: Fithriyah A F , Nasrullah N , Sulistyantara B
Published: November 2021

On 31st March 2020, Indonesia pulls out a large scale social restriction (LSSR) policy to depress the spread of Covid19. The regulation leads to the lay-off of schools, workplaces, worship places, and public facilities, including public parks. Despite the time, it is only a matter of time until the new normal and reopening of all public facilities. For that, public parks as public facilities should be prepared in a way before it is reopened so as not to worsen the situation or even create a new pandemic wave. It is an excellent opportunity to build better by applying health protocol for a healthier future, and transforming the future sustainable landscape. This research is studying two public parks in Bogor City, a satellite city of the megapolitan Jakarta area, which affected the most by Covid19, i.e.,, Sempur Park and Kencana Park. This research aims to explore users’ perceptions and preferences of using public parks to plan health protocol for public parks in the new normal era. Data collected through an online questionnaire survey. As much as 192 responses are analyzed. Data and instruments are valid and reliable, with an overall Cronbach alpha value of 0.896. Results showed that the perception of park use pre-LSSR and post-LSSR was significantly different. The trend of park use was similar but at different levels. This indicates that the motivation and willingness to visit and use public parks is decreasing, therefore applying health protocol is a necessity in the future. This study also found that existing parks perceived to be quite appropriate in accordance with health protocols and need to be moderately modified. Another finding was that the considered most required health protocols application were procurement of handwashing facility, park benches placed at least 1 meter apart, and solitary park bench. It is elicited that despite the type of park, the visitors’ preference was the same.
The political economy of soil erosion in Cirasea sub basin, upstream Citarum basin
Authors: Nurysyifa F , Kaswanto  , Kartodihardjo H
Published: November 2021

The current problems of the Upstream Citarum basin, particularly in the Cirasea Sub-Basin, are near related to economic factors and the low political position of the community. One of the reasons is the biophysical aspect, which influenced the erfpacht rights for Dutch and British plantation companies in the Agrarische Wet policy at the end of the 17th century. When Indonesia became independent, the Government had worked on environmental rehabilitation as well as dealing with land conflicts, but rehabilitation activities often failed to meet the primary needs of the community. Therefore, rehabilitation efforts in various programs often fail. The objective of this this study is to figure out the preferences of interests and motives from the government and other access authorities which ultimately affect the lives of other communities through the formulation of an environmental rehabilitation program. The approach is Bernstein Political Economy Analysis. The results show that political economy is be able to reveals the problem of erosion, which is always imposed on groups with a low political position compared to other groups who are more vital in reaching access. Even though the community has limitations in implementing environmentally-friendly agricultural practices. Moreover, the political economy can reveal the government’s interests behind the land rehabilitation program which often sided with big investors and even tended to repeat the pattern of conflicts in the colonial era. Therefore, erosion can be an important element in describing the conditions of poverty that occur in rural areas.
Lovina Beach landscape design in Buleleng Regency Bali based on landscape engineering
Authors: Ramadhan M F , Nuryanti P
Published: November 2021

Lovina Beach is a famous tourist attraction on the northern island of Bali. This beach is somewhat unique because it has an exciting dolphin viewing attraction. However, some lack elements on-site reduce the value of beach tourism, such as unattractive design, many idle facilities, empty spaces, and puddle. This study aims to analyze and redesign the beach based on landscape engineering to overcome sustainability. The design stage consists of project acceptance, research and analysis, design, and construction drawings combined with the scoring system of the hydro-oceanographic analysis. The analysis aimed to identify the value of coastal vulnerability indexes. The results of this study are site plan concepts, perspective drawings, cut images, planting plans, and detailed engineering designs, which is formed on the results of analysis and synthesis, and preferences score. The design of this coastal waterscape will be used as a recommendation to the beach management.
Multi-functional utilization of suburban green space : text mining to analyze “Forest around the Mountains” Satoyama activities
Authors: Xiang Q Y , Mao Y M , Furuya K
Published: November 2021

Due to the acceleration of urbanization, many green spaces are facing the fate of abandonment, especially the urban and suburban green space. In Japan, these suburban green spaces can also be used as a Satoyama. Satoyama is a multi-purpose ecosystem, including some secondary forests, farmlands, lakes, marshes, and so on. They are affected by human beings and benefited each other. It is proof of harmonious coexistence that human beings have been groping for in nature since ancient times. This study collected the records of the Satoyama activity group in Matsudo City, Chiba Prefecture, Japan from 2008 to 2019, and used KHCoder3 to mine the characters. The purpose of this study was to identify that it is found that people use suburban green space in variety nowadays through the activities of volunteers in Satoyama. From the records, the green space has a series of changing stages after becoming Satoyama, in which 2008-2011 is the first stage, and 2016-2019 is the other stage, but 2012, 2014, and 2015 were grouped separately. In addition to the daily maintenance of the forest, there were also some special words that can be seen that people attach great importance to the publicity of Satoyama as a place for Children’s environmental education. For the future, Satoyama activities can afford good references to urban green space multi-function, maintain ecological balance, and keeping sustainable development.