Fault Area Research Articles

Felt earthquake on March 4, 2024, Mw=5.0, in the Kyungey-Ala-Too ridge

The paper presents the results of the analysis of instrumental and macroseismic data of the strong Kungey earthquake on March 4, 2024, on the border of Kyrgyzstan and Kazakhstan in the Kemin-Chilik fault area. The hypocenter of the earthquake is confined to the focal zone of the catastrophic Kemin earthquake of 1911 with Mw=8.2. The earthquake of March 4, 2024 occurred under the action of submeridional near-horizontal compression, which is typical for the sources of the Northern Tien Shan. The type of motion in the source along the steeply dipping plane NP1 of southwestern strike is a reverse type of motion with a left-sided strike-slip component, along the plane of an eastern strike is a thrust with a right-sided strike-slip component. Before the Kungey earthquake, a ring-shaped seismicity structures formed by earthquakes with depths of up to 33 km, which is a prediction’s factor for strong crustal earthquakes. The earthquake was felt in Almaty (Kazakhstan) and its suburbs with an intensity of 5 points on the MSK-64 scale and had the most significant impact on the megapolis after the Baysorun earthquake of 1990. Data on the macroseismic impact of the Kungey earthquake in Kazakhstan and Kyrgyzstan were collected. An analysis of the records of strong motion instruments based on data from Central Asian stations was carried out.

Evaluation of Disaster Risk and Mitigation Strategies for Post-Disaster Permanent Housing in the Palu Koro Fault Area

The Palu Koro Fault in Sulawesi, Indonesia, an area with very high seismic activity, with a historical record of large earthquakes, including the devastating event on September 28, 2018. This earthquake, accompanied by a tsunami and liquefaction, caused significant damage to infrastructure and residential areas in Palu City, Donggala Regency, and Sigi Regency. A future similar event needs to be studied based on technical aspects related to disaster vulnerability criteria. The SNI 03-1733 (2004) establishes the disaster risk criteria in residential areas, such as landslides, floods, and earthquakes. BNPB has also created a disaster-prone map in Indonesia. However, studies on safe housing emerging from various disasters, such as earthquakes, tsunamis, liquefaction, and other risks, specifically being in the path of planes or near high voltage currents, are still limited. This research aims to assess disaster risk in post-disaster permanent residential relocation using the AS/NZS ISO 31000 risk management framework, which includes vulnerability conditions, evaluation of technical aspects, disaster risk analysis, and development of recommendations, combining quantitative and qualitative approaches. Data were analyzed using a scale-based method, with descriptive statistics to calculate frequency, averages, and percentage of the risk categories at each location. Qualitative analysis produces narratives regarding the impact of risks on community safety and residential infrastructure. The current study results show that high-risk factors, including earthquakes, floods, and landslides, require immediate mitigation. Additionally, immediate action should be taken for risks categorized as unacceptable, involving building strengthening, drainage system improvement, and soil stabilization, to reduce the risk of liquefaction. Concerning moderate risks, which belong to the undesirable category, they also require further treatment to minimize the impact of future disasters. The current study also emphasizes the importance of community survivors' participation in the relocation and disaster preparation process. This underlines the need for an integrated approach to disaster risk management to strengthen the resilience of communities and infrastructure in disaster-prone areas.

Fault Diagnosis Method for Converter Stations Based on Fault Area Identification and Evidence Information Fusion.

DC converter stations have a high voltage level, a long transmission distance, and complex internal equipment, and contain power electronic devices, which seriously endanger the stable operation of the system itself and the active distribution network at the receiving end when faults occur. Accurate fault analysis and diagnosis are critical to the safe and stable operation of power systems. Traditional fault diagnosis methods often rely on a single source of information, leading to issues such as insufficient information utilization and incomplete diagnostic scope when applied to DC transmission systems. To address these problems, a fault diagnosis method for converter stations based on preliminary identification of the fault range and the fusion of evidence information of the switch signal and electrical quantity is proposed. First, the preprocessing of converter station sequential event recording (SER) events and a statistical analysis of event characteristics are completed to initially determine the range of the fault.Then, a fuzzy Petri net model and a BP neural network model are constructed on the basis of the fault data from a real-time digital simulation system (RTDS), and the corresponding evidence information of the switch signal and electrical quantity are obtained via iterative inference and deep learning methods. Finally, on the basis of D-S evidence theory, a comprehensive diagnosis result is obtained by fusing the switch and electric evidence information. Taking the fault data of a DC converter station as an example, the proposed method is analyzed and compared with the traditional method, which is based on single information. The results show that the proposed method can reliably and accurately identify fault points in the protected area of the converter station.

Study on instability mechanisms and control of coal pillar spalling and coal crumbs leakage during working face crossing faults

The stability of coal pillars in fault areas is crucial for ensuring the safe passage of working faces. Based on field observations, frequent coal pillar spalling and substantial tectonic coal crumbs leakage, as well as tilting of hydraulic supports, are observed when working faces transition from primary coal to tectonic coal. To analyze the instability mechanisms behind these phenomena, this paper establishes a mechanical model of coal pillars in fault areas and analyzes the distribution of tectonic stresses and factors affecting the stability of coal pillars. The results indicate that horizontal tectonic stress adheres to an exponential function dependent on the angle factor, where (k0) is a parameter associated with the friction angle of the coal body, the dip angle of the fault, and the friction angle of the fault plane. The stability of coal pillars is influenced by factors such as roof and floor pressures, coal pillar integrity, mining height, and shield support force, with coal pillar integrity being the most critical. To ensure the smooth passage of working faces through faults, this study proposes a combined control technique of “inclined mining” and “grouting,” including reducing mining heights, adjusting the slope of working face advancement, and pre-grouting of coal pillars. Industrial experiments conducted on-site have shown improved integrity of tectonic coal, enabling the working face to pass through faults smoothly and significantly increasing production efficiency.

Prediction Method for the Distribution of the Effective Dominant Path of Sand Bodies Transporting Oil and Gas and Its Application

To study the oil and gas distribution law in the slope area of a hydrocarbon-bearing basin, one must first define the dominant hydrocarbon transport paths of sand bodies as the superimposed area of the contiguously distributed area of the sand bodies and the paleotectonic ridges at the top interface of the formation. Then, the oil and gas supply area of the oil source faults must be defined, as the overlapped area of the favorable transport paths of oil source faults and the width of their associated fracture zones. Stacking the two areas, we can delineate the distribution of the effective dominant paths of sand bodies transporting oil and gas. The results from our case study of the Qinan area show that the effective dominant paths of sand bodies transporting oil and gas in the lower sub-member within the first member of the Shahejie Formation (Es1L) in the Qinan area are distributed throughout the region, with better development in the west than in the east. And, the effective dominant paths in the eastern part extend from north to south, while those in the western part extend from northeast to southwest. These are favorable for the convergence of oil and gas generated from source rocks in the third member of the Shahejie Formation (Es3) in the main depression of Qikou Sag in the Es1L in the Qinan area. The results are consistent with the fact that oil and gas discovered in the Es1L in the Qinan area are mainly distributed in the central and western regions, with a small amount in the southeast. Therefore, the suggested method is feasible for predicting the effective dominant paths of sand bodies transporting oil and gas.

Rupture behaviors of the southern Xianshuihe fault and seismicity around Mt. Gongga: Insights from the 2022 MW 6.6 Luding (China) earthquake sequence

The 2022 MW 6.6 Luding earthquake occurred on the Moxi segment of the Xianshuihe fault at the southeast margin of Tibetan Plateau, China. To assess the seismic potential of the Moxi segment, we examine the rupture process of the mainshock and aftershock sequence, along with historical seismicity. Our preferred slip model inverted from teleseismic body waves and regional GNSS static displacements shows a dominant southeastward rupture consisting of two distinct, prominent slip patches along strike extending by ∼15 km, with a peak slip of ∼2.8 m, approximately balancing the slip deficit since the last major earthquake in 1786. The northern section of the Moxi segment experienced minor coseismic slip, which, together with the significant slip deficits and positive Coulomb failure stress change induced by the 2022 mainshock indicates a high seismic potential. Several aftershock clusters are distributed along or near the Moxi segment, with strike-slip focal mechanisms around the downdip edge of the coseismic slip area at ∼8‐12 km. At the eastern flank of Mt. Gongga, another cluster of normal faulting aftershocks is located at shallower depths of ∼3‐7 km, with high seismicity rate over ∼9 months including two other M5 sequences in January and February 2023. Similar intense shallow normal faulting activity had occurred after the impoundment of the nearby Dagangshan reservoir in 2015. We speculate that some NW-SE trending normal faults were initially developed by the gravitational collapse of Mt. Gongga underneath the eastern flank, further weakened by fluid flow, as supported by the existence of hot springs and water impoundment, and reactivated by the tensional stress change induced by the 2022 mainshock. These results have important implications for assessing the seismic hazard in and around the Moxi segment, and the potential interplay between strike-slip fault and nearby mountain areas.

A Review Paper on Memory Fault Models and its Algorithms

The significance of testing semiconductor memories has grown significantly in the semiconductor industry due to the increased density of modern memory chips. This paper aims to investigate and analyze different types of functional faults present in today's memory technology. These faults include stuck-at faults, transition faults, coupling faults, address decoder faults, and neighborhood pattern-sensitive faults. The paper also delves into the techniques utilized to identify and detect these faults. In particular, the focus is placed on the importance of zero-one, checkerboard, and March pattern tests, which are widely employed to assess functional memory defects at different levels, such as the chip level, array level, and board level. Furthermore, the study provides an in-depth exploration of various test algorithms and thoroughly examines their fault coverage capabilities. Overall, this review paper provides valuable insights into the challenges posed by the dense nature of modern memory chips and offers a comprehensive analysis of functional faults in memory technology. By emphasizing the importance of testing and presenting a detailed exploration of fault detection methods and test algorithms, this study contributes to the advancement of reliable and high-performance memory devices in the electronic industry suggesting that MARCH algorithms outperform others when considering factors like fault coverage, power efficiency, area optimization, and time complexity parameters, making them the preferable choice for reliable and high-performance memory devices in the electronic industry.

Transition From Reverse to Left‐Slip on the Eastern Haiyuan Fault, NE Tibetan Plateau, From the Structure and Age of the Ganyanchi Pull‐Apart Basin

AbstractBecause the active, left‐slip Haiyuan fault is a first‐order structure along the NE margin of the Tibetan Plateau, its tectonic evolution provides insight into deformation processes along this margin over time. Late Cenozoic deformation in the area of the eastern Haiyuan fault initiated as thrust faulting, followed by left‐lateral strike slip displacement. However, the time of this kinematic change has been long debated. Here we use the structural evolution and the age of the Ganyanchi basin to date the onset of this kinematic transition. Seismic reflection data, integrated with published structural mapping, indicate that the basin is a pull‐apart controlled by strands of the eastern Haiyuan fault. Previously reported magnetostratigraphy of a core from the basin interior indicates deposition started at ∼2.8 Ma. However, this age likely postdates initiation of the bounding strike‐slip faults. We estimate that an additional 0.2–1.0 Myr of lateral slip occurred before the dated section formed. Thus, we find that the age of the eastern Haiyuan fault is at least ∼3.5 Ma, which is significantly older than early estimates of less than 2 Ma. Integrating our new data with prior work reveals that the kinematic change from NE‐SW shortening to left‐slip along the Haiyuan fault youngs to the east, which we interpret to result from growth of the Haiyuan strike‐slip fault via progressive lateral propagation from west to east. Miocene‐Pliocene onset of the Haiyuan strike‐slip fault coincides with initiation ages of other major strike‐slip faults in NE Tibet, likely implying that the NE margin of the Tibetan Plateau had switched to a strike‐slip dominated mode of deformation by this time.

Night Lighting Fault Detection Based on Improved YOLOv5

Night lighting is essential for urban life, and the occurrence of faults can significantly affect the presentation of lighting effects. Many reasons can cause lighting faults, including the damage of lamps and circuits, and the typical manifestation of the faults is that the lights do not light up. The current troubleshooting mainly relies on artificial visual inspection, making detecting faults difficult and time-consuming. Therefore, it is necessary to introduce technical means to detect lighting faults. However, current research on lighting fault detection mainly focuses on using non-visual methods such as sensor data analysis, which has the disadvantages of having a high cost and difficulty adapting to large-scale fault detection. Therefore, this study mainly focuses on solving the problem of the automatic detection of night lighting faults using machine vision methods, especially object detection methods. Based on the YOLOv5 model, two data fusion models have been developed based on the characteristics of lighting fault detection inverse problems: YOLOv5 Channel Concatenation and YOLOv5 Image Fusion. Based on the dataset obtained from the developed automatic image collection and annotation system, the training and evaluation of these three models, including the original YOLOv5, YOLOv5 Channel Concatenation, and YOLOv5 Image Fusion, have been completed. Research has found that applying complete lighting images is essential for the problem of lighting fault detection. The developed Image Fusion model can effectively fuse information and accurately detect the occurrence and area of faults, with a mAP value of 0.984. This study is expected to play an essential role in the intelligent development of urban night lighting.

Analysis of Mineral Types, Density, and Porosity in the Lam Teuba Formation Using Infrared Spectroscopy Method

The Lam Teuba Formation is one of the local fault areas of the Seulimuem segment located in the Grand Mosque sub-district of Aceh Besar regency. The Lam Teuba Formation has several types of rocks such as basaltic andesite lava, pyrolastic flows, pyroclastic falls, and sedimentary rocks, namely claystone, limestone sandstone, agglomerate, limestone. Rocks have physical characteristics, namely density and porosity which have different values in each rock. This difference can be caused by the minerals contained in the rock. The method used to calculate the density and porosity values used the Archimedes method, and the identification of mineral types using the infrared spectroscopy method. The results of data processing obtained the highest original density value at location 1 sample 1 with a value of 3.42 and the lowest value at location 5 sample 2. The highest dry density value was in location 1 of sample 1 with a value of 3.33 and the lowest value was in location 5 of sample 2. The highest saturation density value was in location 1 of sample 1 with a value of 3.43, the lowest value was in location 5 of sample 2 with a value of 2.07. The average porosity value was the highest with a value of 5.41 in the poor quality category in sample 4, while the lowest value was 4.62 in the very bad category in sample 1. The types of minerals found in the Lam Teuba formation are illite, montmorillonite, kaolinite minerals with a mixture of smectite which is a clay mineral group and siderite minerals which are carbonate mineral groups.

The Strike-Slip Fault System and Its Influence on Hydrocarbon Accumulation in the Gudong Area of the Zhanhua Depression, Bohai Bay Basin

The Gudong area contains abundant petroleum resources. Previous studies have mainly focused on the extension structure in this area, with its strike-slip characteristics remaining poorly understood. In this study, the geometry of the strike-slip faults in the Gudong area was investigated using high-resolution 3D seismic reflection and drilling data, as were their associated releasing and restraining structures. Based on the profile’s flower structure and the plane’s horsetail splay pattern, the Gudong fault in the study area can be characterized as a dextral strike-slip. Three types of strike-slip fault-associated structures can be identified in the study area: (a) a restraining bend occurring in the right-stepping area of the S-shaped Gudong strike-slip fault, (b) a restraining bend identified in the left-stepping, overlapping zone of the Gudong and Kendong faults, and (c) a releasing bend seen in the extensional horsetail splay structure at the southern end of the Gudong fault. The restraining stress induced the formation of a fault-related open anticline, which led to a significant increase in fault sealing efficiency, thereby preserving an estimated 75.479231 million tons of oil and 15.28317145 billion cubic meters of gas. Conversely, releasing transtensional stress has compromised the effectiveness of the traps, preventing hydrocarbon retention. Consequently, oil and gas have migrated upward along the horsetail faults to the top of Cenozoic formations and have then dispersed.

Evaluation of Medium-Deep Geothermal Resources Based on Seismic Imaging Technology: A Case Study of the Midu Basin in Yunnan Province

The effective utilization of medium-high temperature geothermal energy is pivotal in reducing carbon emissions and plays a crucial role in developing clean energy technologies. The MiDu geothermal field, situated in the southeastern region of Dali Prefecture, Yunnan Province, lies within the Mediterranean–Himalayan high-temperature geothermal belt and is characterized by abundant geothermal resources. However, due to its considerable depth, exploration poses significant risks, resulting in a total utilization rate of less than 0.5% of the total reserves. This study employs natural seismic data to perform a tomographic analysis of the geothermal system in the Midu basin. By examining the P-wave velocity (Vp) and the velocity ratio of P-waves and S-waves (Vp/Vs) at various depths, the findings reveal that the basin comprises two distinct structural layers: the thrust basement of the Mesozoic and Paleozoic eras and the strike–slip extensional sedimentary layer of the Cenozoic era. A low-velocity anomaly in the central basin corresponds to the loose Cenozoic sedimentary layer. In contrast, high-velocity anomalies at the basin edges correlate with boundary faults and the Mesozoic–Paleozoic strata. Below a depth of 4 km, the Red River Fault and MiDu Fault continue to dominate the basin’s structure, whereas the influence of the Malipo Fault diminishes. The MiDu Fault exhibits higher thermal conductivity than the Yinjie Fault. It interfaces with multiple carbonate and basalt formations characterized by well-developed pores and fractures, making it a crucial conduit for water and a control point for geothermal storage. Consequently, the existence of medium-high temperature (>90 °C) geothermal resources for power generation should be concentrated around the Midu fault on the western side of the basin, while the Yinjie fault area is more favorable for advancements in heating and wellness.

Improvement of the Evaluation of Seismic Risk in Fault Areas by Lidar-Derived Geophysical Data

This study aimed to improve the methods of assessing seismic risk in fault zones based on lidar data in geophysics. The research highlighted this by comparing the newly developed fault maps with the usual methods of fault mapping and how lidar technology developed high-resolution 3D mapping. We conducted mobile and terrestrial LIDAR surveys to produce DEMs and study the attributes of the fault zones. The technique involved mobile lidar systems with different specifications of emitted transmission rate: 45 000 m/s to 52, 100m/s pulse repetition: 190, 000 Hz–220, 000 Hz; and point density: 10223 points/m2 to 14567 points/m2. Terrestrial lidar surveys used scanner heights of 1. 500-1. 700m and obtained the horizontal and vertical sampling density, ranging from 240,456 to 315,678 points per square meter. We used LAStools, Arc GIS, and QISIS software to filter, classify, and visualize the data processing. e applied interpolation techniques such as IDW, Kriging, Spline, and Natural Neighbors to generate DEMs. Research outcomes identified 15 different fault segments with lengths varying from 10. 000-20. 000 km, along with maximum displacements of 0. 987-4. 567 m, and average slip rates of 3. 456-7. 890 mm/year. The most extended fault segment altogether was FS05, which was 20. 000 km with a maximum bidding distance of 4. 567 m and a 7. 890 mm/year slip rate. We discovered that the proposed method successfully filtered out noise points from lidar data, with the noise points varying between 0.111-0.266 million. We created DEMs with vertical rms errors ranging from 0.045-0.050 m. The study revealed that lidar technology offers accurate and dense geospatial data, essential for discriminating between fault zones. This approach dramatically improves seismic hazard analysis and the identification of the best ways to minimize risks. These are increasing lidar surveys in other seismically active regions, using multiple data sources for analysis, and deploying constant surveys in high-risk fault line regions to increase consistency in detecting surface changes and tectonic activity.

Hajat lembur: a disaster literacy on ritual communication on the Lembang fault

The Hajat Lembur is a yearly ritual by Batu Lonceng Villagers, in West Bandung-Indonesia, following the 1956 landslide disaster that occurred in the Lembang Fault area. A series of local wisdom emerged as important messages tucked into the procession that are related to the ritual communication concept. Based on the three interrelated terms of ritual communication: communication, communion, and commonality (Couldry,2003), this research seeks to reveal the meaning of the Hajat Lembur tradition as disaster risk reduction literacy. This research uses a case study approach, conducted by participatory observation in the Hajat Lembur ritual procession in 2023; in-depth interviews with two informants, in the form of opinion leaders who play a central role in the ritual procession; and literature reviews. The results showed that in terms of communication, the Hajat Lembur tradition is interpreted as a transcendent medium about the importance of maintaining harmonisation between humans, nature, and the Creator. In terms of communion, it is a celebration of the sacred Batu Wahyu that led to an agreement to establish a sacred forest, as an area that must be preserved. In terms of commonality, this ritual is a joint expression of the Batu Lonceng Village community about the importance of protecting nature and the environment inherited by the ancestors. Although there is a need for more established local knowledge in this area, this research contributes to the future of disaster mitigation management by emphasising rationality and local wisdom in dealing with natural disasters.

Study on Catastrophic Evolution Law of Water and Mud Inrush in Water-Rich Fault Fracture Zone of Deep Buried Tunnel

To study the evolution law of water and mud inrush disasters in the fractured zones of water-rich faults in deep buried tunnels, a self-developed 3D physical model test system was used to conduct experimental research about the evolution process. Additionally, MIDAS GTS NX 2022 version was used to analyze the evolution laws of displacement, stress, pore water pressure, and seepage flow velocity during the excavation process. The findings indicate that in the model testing, tunnel excavation caused different changes in the stress magnitude of the surrounding rock at different positions. The pore water pressure increases correspondingly with the loading water pressure at the same location. The function relationship between the relative water pressure coefficient of any point in the outburst-prevention rock mass, and the vertical distance from that point to the upper boundary of the fault, was obtained through nonlinear fitting. In numerical simulation, excavation affects the vertical displacement of the arch vault more than the arch ring, while it has a greater impact on the horizontal displacement of the arch ring compared to the arch vault. The maximum and minimum principal stresses show significant changes; the pore water pressure at each monitoring point decreases with the increase in excavation distance. The flow velocity of seepage shows a trend of first increasing and then decreasing. The research results can provide relevant references for the prevention of water and mud inrush disasters in fault areas.

Evaluation of the tectonic activity of faults with mineral alterations: A case of East Anatolian Fault-Palu Segment, Turkey

Palu segment is a part of the Eastern Anatolian Fault Zone (EAFZ), the most important active left-lateral strike-slip fault system in Turkey, and there are different mineral alterations in this zone. In the study, the spatial relationship between tectonic activity and mineral alterations was tested with the Getis-Ord Gi* statistic in and around Palu segment. Mineral alterations at the pixel level were determined from ASTER images by Ratio, Relative Band Depth (RBD), Mineral Indices, CROSTA, Constrained Energy Minimization (CEM), Mixed Tuned Matched Filter (MTMF) methods. According to the results, the spatial distribution of alteration minerals extending parallel to tectonically active fault lines and/or partially bounded by faults in the area. RBD, Mineral Indices, CROSTA, CEM, and MTMF image processing algorithms applied in the study gave consistent results in the spatial determination and mapping of hydrothermal alterations in the study area. At 99% and 95% confidence intervals, statistically significant cold spot clusters indicate the proximity of alterations to faults concentrated around fault lines. This degree of clustering of mineral alterations indicates regions with high alteration rates close to fault lines and areas with tectonic activity along fault lines.

Fault Handling and Localization Strategy Based on Waveform Characteristics Recognition with Coordination of Peterson Coil and Resistance Grounding Method

To address challenges in locating high-impedance grounding faults (HIGFs) and isolating fault areas in resonant grounding systems, this paper proposes a novel fault identification method based on coordinating a Peterson coil and a resistance grounding system. This method ensures power supply reliability by extinguishing the fault arc during transient faults with the Peterson coil. When a fault is determined to be permanent, the neutral point switches to a resistance grounding mode, ensuring regular distribution of zero-sequence currents in the network, thereby addressing the challenges of HIGF localization and fault area isolation. Fault calibration and nature determination rely on recognizing neutral point displacement voltage waveforms and dynamic characteristics, eliminating interference from asymmetric phase voltage variations. Fault area identification involves assessing the polarity of zero-sequence current waveforms attenuation during grounding mode switching, preventing misjudgments in grounding protection due to random initial fault angles and Peterson coil compensation states. Field experiments validate the feasibility of this fault location method and its control strategy.

Optimized Fault Detector Based Pattern Recognition Technique to Classify and Localize Electrical Faults in Modern Distribution Systems

This research presents a method that integrates artificial neural networks (ANN) and discrete wavelet transform (DWT) to identify and classify faults in large power networks, as well as to pinpoint the zones where these faults occur. The objective is to enhance reliability and safety by accurately detecting and categorizing electrical faults. To manage the computational demands of processing the extensive and complex data from the power system, the network is divided into optimal zones, each made visible for fault detection. Niche Binary particle swarm optimization (NBPSO) is employed to place the fault detectors (FD) in each zone. This allows for precise measurement of fault voltage and current phasors without significant cost. The ANN module is tasked with identifying the fault area and locating the exact fault within that zone, as well as classifying the specific type of fault. Discrete Wavelet Transform is used for feature extraction, and a phase locked loop (PLL) is used for load angle computation. The proposed method's validity has been tested on the IEEE-33 bus distribution network.

Predicting the Magnitude of Possible Earthquakes in the Shahrood District of Khalkhal County, Ardabil, Iran, Using Artificial Neural Networks

Background and objective Earthquakes are natural disasters that can cause high damage. Prediction of earthquakes is necessary to reduce damages, develop resistant infrastructure, and prevent the loss of life in human societies. This research aims to predict the magnitude of possible earthquakes in the Shahrood district of Khalkhal County using artificial neural networks (ANN). Method A multi-layer perceptron neural network was used to predict earthquake magnitude. Results The results showed that in the fault areas, especially the Kalur fault, earthquakes with a magnitude of 1-3 on the Richter scale are more likely to occur (70%). The likelihood of earthquakes with a magnitude of 4-6 on the Richter scale is moderate (26%) and the earthquakes with a magnitude of 7-10 on the Richter scale have a very low probability (4%). Conclusion In future studies, it is recommended to use machine learning models to better and more accurately predict earthquakes in the studied area.

Imaging the Fault Plane Structure of Palu-Koro Fault from Earthquake Data Using Python

Abstract Palu-Koro Fault is one of the active faults located in Sulawesi and positioned in the middle of the Island, dividing the west and east-southeast arms. Its long history of earthquakes provides sufficient focal mechanisms data to be analyzed. This research used seven focal mechanism data of shallow magnitude earthquakes surrounding the pull-apart basin area of the Palu-Koro Fault. The focal mechanism data used is secondary data obtained containing the information needed. This research aims to create a 3D model of the pull-apart basin displaying the geometries of the fault planes and providing a closer look at the fault system surrounding the bounding fault zones. Python script was made to classify the mechanism of each earthquake based on its correlation to the trend of the Palu-Koro Fault. Nodal planes are categorized as whether it is presumed to be the fault plane or the auxiliary plane of the focal mechanism. The result found that not all earthquake data was classified through the assumed parameter set. Only five of seven earthquake data managed to be classified, while the rest showed a different focal mechanism. It is found from the python script created revealed the presence of three fault types: normal fault, normal left lateral oblique fault, and left lateral strike-slip. The 3D fault plane interpolation showed two distinct dipping directions, suggesting their association with the basin’s bounding fault, either the west or the east side. From the gathered information, previous research, and geological interpretation, the earthquake data can be concluded into three fault associations to the bounding fault: synthetic extension fault, antithetic extension fault, and sinistral strike-slip fault.