Palu Area Research Articles

Identification of Subsurface Structure Causing Liquefaction in Palu City Based on Gravity Anomaly

Abstract Liquefaction in Balaroa and Petobo, Palu City occurred following the September 28 2023 earthquake which was triggered by movement of the Palu-Koro fault. It is necessary to study the existence of local geological factors which may be the cause of liquefaction in these areas. One of the contributing factors could be the existence of small structures as a follow-up to the main structure of the Palu-Koro fault. Using gravity methods at both regional scales for the Palu area and detailed scales in the Balaroa and Petobo areas to identify the presence of subsurface structures. In June 2023, gravity measurements were carried out after the Palu-Donggala earthquake in the Palu City and its surroundings. The measurement results of the gravity anomaly map in the Palu City are in the range of gravity anomaly between -4 – 66 mGals. The Balaroa region is in the gravity anomaly between 19.5 – 34.5 mGals, while Petobo is in the range -2 – 10 mGals. The gravity anomaly map shows the appearance of a structure which is characterized by the contrast of the anomalies which form a lineament which is believed to be a structure. The results of the analysis of gravity anomalies confirm the existence of small structures trending west-east and north-south in the Balaroa and Petobo liquefaction areas which may be one of the causes of liquefaction.

Detrital zircons and heavy minerals from the Palu Formation, Sulawesi, Indonesia: constraints on exhumation of the Palu Metamorphic Complex and drainage evolution

The Palu Formation, previously known as the Celebes Molasse in the Palu area, is understudied and was previously considered to be associated with the Pliocene collision between an Australian-derived microcontinent (Banggai Sula) and the eastern margin of Sundaland (West Sulawesi). Here, we present sedimentological, heavy mineral and zircon geochronological data to provide insights into sediment provenance and to elucidate Neogene tectonic activity in Sulawesi. These analyses suggest that the Pleistocene Palu Formation comprises synorogenic alluvial fan to braided river deposits that record the rapid uplift of metamorphic and granitoid rocks in the Neck and west Central Sulawesi. The Palu Formation is characterized by predominant granitoid and metamorphic clasts and heavy mineral assemblages dominated by pyroxene, amphibole and garnet. Detrital zircons record youngest grain ages of c. 2.5 and 3.0 Ma with a significant Pliocene age population and subsidiary Eocene, Cretaceous, Jurassic and Late Triassic age peaks. Rapid uplift and erosion associated with mountain building shaped the topography and influenced the evolution of Palu River networks. Supplementary material : Complete location, heavy mineral and detrital zircon geochronology datasets are available at https://doi.org/10.6084/m9.figshare.c.7033388 Thematic collection: This article is part of the Mesozoic and Cenozoic tectonics, landscape and climate change collection available at: https://www.lyellcollection.org/topic/collections/mesozoic-and-cenozoic-tectonics-landscape-and-climate-change

COVID 19 Influence on Performance of PT Pegadaian Area Palu During 2019-2021 Period

The Covid-19 pandemic has had a significant impact on various sectors, including the financial and banking sectors. One of the financial institutions affected is PT Pegadaian Area Palu. This pandemic has drastically changed economic and business conditions, so it is necessary to conduct research to understand its effect on the performance of PT Pegadaian Area Palu. The purpose of this study is to analyze the effect of the COVID-19 pandemic on the performance of PT Pegadaian Area Palu during the 2019-2021 period. This research used a quantitative approach, while the data collection technique was carried out by literature study and questionnaires to employees of PT Pegadaian Palu Area. The research sample was selected using random sampling technique. The data collected will be analyzed using statistical analysis methods with the help of the SPSS program. The results showed that Covid-19 had a significant influence on the performance of PT Pegadaian Palu area 2019-2021 period. PT Pegadaian Palu Area has been able to turn challenges due to the Covid-19 pandemic into opportunities and maintain positive performance by focusing on employee health, increasing operational efficiency, and strong collaboration, the company has successfully faced the impact of the pandemic and is able to adapt well.

An Ethnosemantic Study of Palu Toponym and Its Association with Natural Hazards

<p><em>This research investigates how the naming of locations in Palu, Central Sulawesi, Indonesia describes the geographical and social conditions in the local area. After the earthquake and tsunami on September 28 2018, in Palu, considerable geographical studies have desired to discover the causality of this catastrophic natural phenomenon. Nevertheless, behind it all, the Kaili tribe, an indigenous tribe on the mainland of Central Sulawesi, believes that several areas in Palu are unfit for habitation because of the history of natural events that have occurred. They sketch this information using toponymy that modern society has often ignored. Moreover, acculturation and globalization have made people overlook local culture and history. The present study operated a different perspective to reveal that the toponymic naming in the Palu area. Those toponyms are derived from the Kaili language reflecting geographical conditions, history and vegetation. The researcher discovered that based on ethnolinguistic fact, several zones were the hotspots of the worst earthquakes and liquefactions and reflected in several toponyms that today's society has forgotten. Using ethnosemantics tracing, historical, and geographical observation and involving cultural and indigenous figures, the researcher answered this phenomenon based on evidence. The implications and results of the findings of this study will be discussed further in the discussion section.</em></p>

Monitoring PV Output Power in Tropical Climates Under Surface Temperature Distribution Area

The performance parameters of a solar panel are influenced by many factors, including the type of panel, area, solar radiation, ambient temperature, and weather. This study aims to analyse the effect of solar radiation and temperature on the performance of monocrystalline solar panels. This research was located in Palu, one of the cities with high temperatures in tropical Indonesia. The study used 50 Wp PV, which was placed in the eastern Palu area based on the spatial distribution of surface temperature with the highest temperature distribution. Data sampling is 25 times per day from 11:00 am – 03:00 pm. The result is that increased surface temperature of the solar panel impacts the decrease in the output power of the PV. The environmental temperature of 32.87 °C in the East Palu area causes a decrease of PV power by 2.3%.

Comparison of Regulations and The Role of Officials Making Land Deeds In The Reconstruction of Land Registration After Natural Disasters

Indonesia is a country that is on the equator and most of it is a water area. Indonesia is also a country located on the Asian and Australian continents and is directly adjacent to the pacific and indian oceans. So this is what causes Indonesia to be included in the Ring of Fire or Pacific Circle of Fire which is known as a region with many tectonic activities. This legal writing uses normative research methods so that the approach used is a purely normative approach or what is known as normative juridical. This research raises the issue of positive legal provisions of the role of land deed-making officials in the implementation of land registration reconstruction after natural disasters. The implementation of land registration after the natural disaster that occurred on September 28, 2018, Indonesia was hit by an earthquake and tsunami precisely in the Palu area of Central Sulawesi is certainly inseparable from applicable government regulations which are still carried out with various collaborations with other ministries as a form of land registration and provide certainty to legal protection for victims of natural disasters

Risk factors of chronic rhinitis in furniture workers of West Palu, Central Sulawesi.

Chronic Rhinitis is an inflammatory disease of the nose characterized by sneezing, snotty and nasal congestion, intermittently or persistently. The prevalence of rhinitis in the United Kingdom reaches 29%, in Indonesia is not known clearly. The types of work that cause rhinitis are chronic like farmers, laboratory workers, carpenters or painters, food industry workers and, health workers. Chronic Rhinitis can affect the quality of the worker’s life, and it can reduce work productivity Objective: To determine the risk factors for chronic rhinitis on the workers in wood furniture which was contacted by sawdust in the West Palu area Method: This study uses analytical research methods with a cross-sectional approach. The sampling technique is total sampling, and the total sample in this study is 27 workers. Results: The study showed a significant relationship with the incidence of rhinitis to the carpenters who work on wooden furniture in the western Palu on age (p = 0.027), duration of exposure (p = 0.041. There was no significant relationship between the use of PPE (p = 0.100) Conclusion: The factors that can influence the incidence of chronic rhinitis to furniture workers are age and duration of exposure

Hazard Study of Earthquake and Liquefaction in Correctional Institution Palu, Central Sulawesi

Earthquakes in Palu and surroundings area on 28 September 2018 gave the significant impacts to publicfacilities damage, such as the Correctional Institution Class II A Palu. The correctional institution areawhere was located only ±300 metres from the liquefaction zones in Petobo also hit by the phenomenon ofliquefaction triggered by the earthquake. Based on The Regulation of Ministry of Laws and Human RightsRepublic of Indonesia article 4 point (d) stated that correctional institutions are located far away from thepossibility of natural hazards (earthquakes, floods, landslides) and integrated with wastewater disposal toavoid environmental effects (Minister of Law and Human Rights Regulations, 2011). The disasters thatoccurred should be the challenge and the problems for Correctional Institutions Palu in undertaking thecompulsories and the functions in disaster-prone area. The first objective of this study was to analyse theearthquakes and liquefaction threat in Correctional Institution Palu area. Threat level index of Correctional Institutions Palu obtained from the threat level zone maps within the 2018 events by DIBI and USGS. Thehazard map conducted through analysing types of earthquake threat related to disaster events in the studyarea. Moreover, observation and interview conducted for the data collection. This study found theCorrectional Institutions Palu area was categorized as earthquakes-prone area, as the impact re-establishingof special patterns for correctional institutions location should be re-investigated.

Implementation of Building Information Modelling for Road Rehabilitation and Reconstruction Project: Liquefaction Disaster of Palu Area

Purpose: Utilization of Building Information Modeling (BIM) is believed to improve planning accuracy, mitigate construction risks, and better plan the entire life cycle of infrastructure asset projects. The application of BIM technology in post-disaster management can combine GIS technology (Geographic Information System) with BIM technology itself, or commonly referred to as geospatial BIM. The purpose of this paper is to apply BIM technology, explain the stages of road planning and modeling with BIM, and identify the advantages of using BIM compared to conventional methods. The road planning location is the location of the Jono Oge liquefaction disaster, Palu, Indonesia.
 Design/methodology/approach: Data collection, data processing with Agisoft Metashape, DEM data input, and orthophoto image data processed by Agisoft Metashape to Autodesk® InfraWorks®, road planning with Autodesk® InfraWorks®, road planning model output and field data presentation. 3D models, IMX format files, FGDB format files, and animation videos.
 Findings: The application of BIM technology in planning and modeling road projects at liquefaction locations can be made using Agisoft Metashape software to process aerial photo data taken using drones and using Autodesk® InfraWorks® software for planning and modeling of the road.
 Research limitations/implications: Modeling Road design in the application of BIM and the use of Autodesk® InfraWorks® applications on the project. We are not modeling the pavement, just visualizing the geometry of the road.
 Practical implications: BIM implementation can drive time, effort, and realistic 3D visualization.
 Originality/value: Original paper
 Paper type: A case study

Pore Pressure Responses of Liquefied Numerical Sand Columns

The Palu 28 September 2021 M 7.5 Earthquake has brought several new challenges to the understanding of liquefaction and its following geotechnical phenomena. In addition, that main shock was followed by a series of aftershocks within a short time frame. The common geotechnical conditions of Palu area include layered soils conditions, and the associated variability of geotechnical conditions exists. This paper reports the dynamic effective stress analysis (ESA) study of four different liquefiable layered sand columns, and the above three conditions (layered soils, variability, aftershocks) are explicitly modeled. The dynamic ESA employs the PM4Sand constitutive model for liquefiable sands, implemented in the OpenSees platform. Three ground motion sets (“main shock only”, “main shock plus aftershock”, “aftershock” only) of variable amplitude, single frequency harmonic motions are used. The models are validated by comparing qualitatively their results against laboratory test results and field measurements. The saturated sand layers in all cases subjected to “main shock only” are liquefied with different detailed excess pore pressure (EPP) responses, highlighting the importance of the system response of liquefying sand columns. The cases subjected to “main shock plus aftershock” show a much a longer higher EPP state, while cases subjected to both “main shock plus aftershock” and “aftershock only” indicate a longer liquefaction state during the aftershock. The implication of the longer duration in the higher EPP state and the longer liquefaction state is that a longer duration of lower shear strength conditions would exist. The different EPP responses resulted from different geotechnical conditions represented by the four sand columns suggest that the variability of geotechnical conditions would have an important influence on the system response.

Equivalent-linear seismic ground response analysis in Palu area

The 7.5 Mw Palu earthquake on September 28, 2018, was caused by the Palu Koro fault. This earthquake produced forceful wave propagation in the soil layer and generated enormous surface damage in Balaroa, Petobo, and Jono Oge. Estimations of soil amplification at a specific location are helpful as guidance for infrastructure development. This study examined the effect of local soil in modifying the one-dimensional linear soil response in Balaroa, Petobo, and Jono Oge regions, considering the data of various sites in those regions. The soil response was observed to obtain the synthetic input motion and its effects in the time history of surface acceleration, the ratio of shear stress to effective vertical stress to spectrum response time, and the Fourier amplitude versus frequency ratio. Amplification is standard for ground acceleration, which considers the strong ground motion with the acquired frequency and duration of the content. The results showed that the peak of ground acceleration amplification factors for Balaroa, Petobo, and Jono Oge was around 1.49, 2.05, and 1.27 times, respectively. With a lack of information at the particular site, designers will use the response spectrum obtained along the soil layer to develop earthquake-resistant geotechnical structures in locations close to Palu.

Landslides triggered by the 2018 Mw 7.5 Palu supershear earthquake in Indonesia

On September 28th, 2018, a supershear earthquake of moment magnitude (Mw) 7.5 struck the Palu area in central Sulawesi, Indonesia. To gain insight into landslides triggered by the Palu earthquake, a detailed landslide interpretation project was carried out in the meizoseismal area. To establish a co-seismic landslide inventory, we collected high-resolution images, including Worldview pre- and post- earthquake images, Sentinel pre- and post- earthquake images and Google Earth pre- and post- earthquake images. The results show that the Palu event triggered at least 7063 co-seismic landslides, including 8 flowslides. The total landslide area is 29.7 km2, with the highest density being 96 landslides/km2. The rock type (Kambuno granite) is a dominant factor influencing the landslide distribution; the average landslide H/L (H is the fall height and L is the horizontal length of an entire landslide) is 0.56. The flowslides that occurred in the Palu Basin are seismic liquefaction-induced landslides that failed along very gentle slopes (generally, slopes that are <3°) and traveled hundreds to thousands of meters, and the average H/L was 0.021.

Phytochemical Screening and Antioxidant Activity Test of Red Onion (Allium ascolinicum L.) Extract Variety of Palu Valley

The red onion of Palu valley variety is a plant that is widely found in Palu area and regarded as a leading commodity in Central Sulawesi. The purpose of this study was to examine the secondary metabolite compounds contained in red onion (Allium ascolinicum L.) of Palu valley variety and its antioxidant activity. Antioxidant activity test in this study used DPPH (1,1-Diphenyl-2-Pikrilhidrazil) as a source of free radical, and vitamin C as the comparison. The antioxidant activity of red onion extract was analyzed using a UV-Vis spectrophotometer. The red onion tuber powder was extracted by maceration using ethanol solvent. Qualitative test of onion powder showed positive results on alkaloids, flavonoids, and tannin compounds. The samples and vitamin C were tested for antioxidant activity in various extract concentrations of 10, 30, 50, 70, and 90 ppm. The results showed that red onion extract of Palu valley variety presented an IC50 value of 38.548 ppm, and vitamin C presented an IC50 value of 22.646 ppm. Based on these values, the red onion (Allium ascolinicum L.) extract is categorized as a very strong class of antioxidant which can be used as a source of natural antioxidant.

Reduksi bising seismik secara adaptif menggunakan filter Wiener

Seismic noise disrupts the earthquake observation system due to the frequency and amplitude of seismic noise similar to the earthquake signal. The filter process is one of the methods that can be used to reduce seismic noise. In this study, the Wiener filter algorithm was designed with the Decision-Directed method for Apriori SNR estimation. This filter was chosen because it is adaptive, so it can adjust to environmental conditions without requiring manual parameter settings. The data used are earthquake signals that occur in the Palu area, Central Sulawesi, which are recorded on PKA29 temporary seismic station from February 3 to April 28, 2015. After each signal data has been filtered, then it is evaluated by calculating SNR differences before and after filtering, the signal's dominant frequency, and the cross-correlation of the signal before and after filtering. As a result, the Wiener filter is able to reduce the noise content in earthquake signals according to noisy frequencies before earthquake signals. The impact is that SNR has increased with an average of 8.056 dB. In addition, this filter is also able to maintain the shape of earthquake signals. This is indicated by the normalization value of the cross-correlation between signals before and after the filter which ranges from 0.703 to 1.00.

Spatial analysis of the liquefaction vulnerability zone based on the phreatic level at the Palu groundwater basin, Central Sulawesi Province

An earthquake with a magnitude of 7.4 in Palu City and Donggala District in Central Sulawesi Province on September 28, 2018 has caused a liquefaction disaster. Basically liquefaction can occur in earthquake prone areas, shallow phreatic depth and poorly consolidated soil. This study attempts to examine the relationship between phreatic depth and the probability of liquefaction. The research method is an analog and numerical relation model, by combining the aquifer system model and groundwater geographic information system with landuse patterns in areas affected by liquefaction disasters. This method is described in Spatial and Environmental Analysis, which is supported by the use of satellite imagery and the analysis process with the Arc View Gis 3.3 program. The results showed that there was an influence between rainfall on the spatial distribution of phreatic depth, with the average rainfall in the Palu area being 68.74 mm / month and the depth of phreatic level ranged from medium (2.5 - 7.0 meters from ground level) - shallow (<2.5 meters from ground level). Based on the phreatic depth of the Palu groundwater basin, the chances for liquefaction are in the medium to high zone class.

Estimation of ordinary kriging parameters for determining characteristics and distribution of groundwater layer in Tondo area, Mantikulore district, Palu

Tondo area as a research location is one of Palu area. The topography of this area besides sloping and interspersed with hilly areas is also a barren and critical groundwater area. Geologically, the rock structure that comprises this area consists of Molasa Celebes deposits namely clay, sand and gravel. So far, clean water in the Tondo area has been supplied by the Palu City Regional Drinking Water Company (PDAM) from the surface water source in Kawatuna area. There is also a PDAM Donggala that supplies clean water to this area which is sourced from groundwater. However, the water source is quite deep at around 150 m besides that the depth of groundwater position varies based on the results of groundwater drilling in this region and groundwater cannot always be found. If these results are followed up with Ordinary Kriging research using a Semivariogram to find groundwater, the results are expected to be better and more accurate. Based on the research results obtained that: The best model is the Spherical model with the smallest MSE value of 429.5016 and the resulting parameter values are nuggets = 15.70937, sill = 28.46195, and range = 3343.121. The deepest depth is 23.07785 m.

Tsunami Evacuation Routes Optimization using Genetic Algorithms: A Case Study in Palu

Palu area and its surroundings, besides being very prone to earthquakes, are also prone to tsunamis. A devastating earthquake occurred On September 28, 2018, followed by a destructive and deadly tsunami that struck Palu Bay. This makes the need for proper planning in overcoming the tsunami disaster. One of them is by showing the evacuation route for people in tsunami-prone areas. This study aims to show the best route to the safe point of the tsunami using Genetic Algorithm. The results of the studies show that the best route for tsunami evacuations can be provided best depend on the available of the safe points. Some clusters, namely 9, 10, and 12 have few safe points, limiting people to access a safe location from the tsunami.

Geomorphological impact of Palu earthquake

Sulawesi and Maluku islands are tectonically under a collision area of four earth crust plates, those are Eurasia, Philliphines Islands, Pacific Ocean and Australian-India Ocean. Palu city in Central Sulawesi island in particular is geologically an area of complex structure. A fault zone of north-west to south-east direction has formed Palu area as a block being squeezed by Palu-Koro strike-slip fault zone. The aim of this research is to know the impact of earthquake happened on October 28, 2018 has caused the fault to activate of being dynamic movement of the area. Using hand camera photos, a morphological survey and analysis show the landslides and slumps could be clearly identified. Rock and soil slide and movement was also strengthened by liquefaction of hydrological fluid content within the Palu block. Morphology of Palu-Koro fault plane was also affected significantly causing landslides and slumps on the fault plane exposed in the earth surface.

Correlation of geological conditions and levels of damage in Palu earthquake

The earthquake was occurred in Palu with magnitude 7.4 SR on September 28, 2018. The earthquake caused damage in infrastructure, settlements and casualties. The earthquake also caused liquefaction in Petobo and Balaroa. One of the factors that influence to the level of damage is geological conditions such as geological structures (faults) and rock types. The presence of faults determines the earthquake zone, so that it greatly affects the level of damage. The type of rock in Palu generally consists of allufial deposits and sedimentary rocks, make the level of damage that occurs has different levels. The results from survey showed that the level of damage to buildings was strongly related to the earthquake zone and rock conditions. Earthquake induce damage more intensively in locations with rocks in the form of soft allufial deposits and closed to the earthquake zone. This condition can be taken into consideration in earthquake disaster mitigation actions. The arrangement of the city of Palu must be carried out with careful planning because the Palu area is on a high tectonic route. To reduce the risk of disasters, structuring and development need to consider a map of earthquake-prone zones of damage.

RANCANG BANGUN ALAT PEREKAM DATA LIKUIFAKSI BERBASIS ARDUINO NANO

Central Sulawesi, precisely in the city of Palu, is one of the areas that frequently occurs in earthquakes and has high seismicity. The regional geology of the Palu area and its surroundings is dominated by quarterly deposits consisting of fluivatil and alluvium deposits. These natural conditions have several potentials that are detrimental, including the potential for liquidity. (Widyaningrum, 2012).&#x0D; Liquidation is an event that occurs when a soil becomes saturated or loses its ability to support the mass above it because the land changes form into heavy water or becomes liquid. Lack of further knowledge about the faction by the surrounding community causes a lack of vigilance in dealing with the faction.&#x0D; The things that people need to know about potentially liquefaction soils are data on soil moisture, changes in underground temperature, and vibrations that are felt underground when earthquakes occur shortly after liquefaction using a device in the form of an arduino nano-based data recorder. The Design of Arduino Nano Based Likuefaction Data Recording Tool can be used to record and record data on lycufaction disaster events. And is used to make it easier to analyze the potential occurrence of liquefaction in certain regions by utilizing the sensor to measure soil temperature, soil moisture, and vibrations that occur in the soil.