Earthquake Return Period Research Articles

Investigation of Earthquake Disaster Risk Using ArcGis Satellite Imagery Study Case in North Tapanuli Regency

Abstract Earthquakes are one of the natural phenomena that occur surprisingly without any signs or symptoms that can be felt by humans, so that generally earthquakes cause tremendous panic. Tectonic earthquakes from faults generate a Peak Ground Acceleration (PGA) value, which helps assess their risk impact. North Tapanuli Regency is one of the districts in Indonesia that is passed by two faults, namely Renun and Toru. To determine the risk of earthquake disasters in the area, calculations are carried out using spatial methods to obtain values of PGA, Mmax, and Tmax values. From the processing results, it is known that the maximum magnitude of the Toru segment is 7.37 M and the Renun segment is 7.69 M, and the Toru segment has a maximum earthquake return period in the Toru segment of 429 years and the renun segment has a return period of 1013 years. Also, a disaster mitigation map is obtained that is formed using the PGA value as a parameter, with an explanation that areas that have a higher PGA value (colored red) have a greater risk of being affected by an earthquake.

Study of Earthquake Hazard Probability Based on PGA (Peak Ground Acceleration) Using the PSHA Method in Semarang Regency, Indonesia

Semarang Regency was one of the areas affected by the earthquake. This happens because it is located north of the subduction zone and has active faults, so research is needed to identify the impact of earthquakes in Semarang Regency as an initial action in disaster mitigation efforts. This research aims to determine the distribution of PGA values in the Semarang Regency area and to assess the seismic hazard due to earthquakes based on a map of the distribution of PGA values in the Semarang Regency area. The method used is the Probabilistic Seismic Hazard Analysis (PSHA) method, which uses earthquake catalogues from BMKG, USGS, IRIS, and ISC. The earthquake source data was the n processed using ZMAP and R-CRISIS software. The results of seismic hazard analysis in the Semarang Regency area for a probability of exceeding 10% in 50 years or an earthquake return period of 475 years in bedrock with a period of 0 seconds obtained a PGA value ranging from 0.368–0.844 g, for a short period of 0.2 seconds the PGA value obtained ranged from 0.647. –1.773 g, for 1 second, the PGA value obtained ranges from 0.320–0.852 g. The highest PGA value is in West Ungaran District, with a value of 0.844 g. The lowest PGA value is in Kaliwungu District, which has a value of 0.458 g. The active fault zones influence the danger of earthquakes in the Semarang Regency area in Semarang Regency.

The 2024 Mw 7.0 Wushi Earthquake in Southern Tianshan Convergent Zone: Finite-Fault Model for the Coseismic Rupture and Aftershock

Abstract On 22 January 2024, an Mw 7.0 earthquake struck the oblique thrust Maidan fault (MDF) at the boundary between the Southern Tianshan and Tarim basin, making it the largest earthquake on the fault in the last 100 yr. Here, we use Interferometric Synthetic Aperture Radar (InSAR) to retrieve coseismic and aftershock deformation caused by the earthquake and then constrain fault geometry and slip distribution. Line-of-sight InSAR observations revealed a coseismic deformation area of 70 km × 60 km with a maximum value of ∼0.8 m and also captured the deformation from the aftershock event seven days after the mainshock. Our preferred two-segment coseismic fault model ruptures the MDF locked segment and deeper regions, exhibiting a homogeneous elliptical rupture with a maximum slip of ∼2.7 m on a rectangular plane with a dip angle of ∼60°, a length of ∼55 km, and a depth between 5 and 20 km. The aftershock formed a rupture plane of 10×8 km2 with the maximum slip of ∼0.3 m, causing slip in the shallow area of the fault where the coseismic ruptures were smaller, and supplementarily released the stress in the shallow part of the fault. The strong earthquake (Mw 7) return period on MDF inferred from the interseismic slip rate is 170–200 yr. Oblique thrust slip revealed by the slip distribution model is the result of long-term absorption of oblique convergence strain in the Southern Tianshan by the MDF and then concentrated release. The 2024 event resulted in a 60 km unruptured segment on the MDF being in a stress-triggering zone, increasing the potential seismic hazard, in contrast to the delayed seismicities on 100 km region of the southern Kalping fault (KPF).

Seismic Safety Evaluation of Mechanically Stabilized Earth (MSE) Wall for Highway Construction

The usage of Mechanically Stabilized Earth (MSE) Walls has grown in popularity over the last few decades and has been widely used in many countries for highway construction, including Indonesia. As a country with a high risk against seismic hazards, a considerable stability analysis against earthquakes for construction must be conducted. This paper is directed to evaluate the static and seismic stability of MSE wall by adopting design criteria from SNI 8460:2017 using the pseudo-static approach with Limit Equilibrium Method (LEM) which modelling earthquake as a seismic coefficient, a one-way constant load and dynamic response approach with Finite Element Method (FEM) which modelling earthquake as ground motion, a fluctuating load which varies in time. The stability analysis is performed by considering three failure mechanisms that mostly occurred in MSE Walls; base sliding, tensile overstress, and slope failure. The earthquake load is modelled based 1000-year return period earthquake. Based on the analysis result, the most potential failure mechanism that may occur in the MSE wall is tensile overstress, while the least potential failure is base sliding. The analysis result also shows that the finite element method obtained higher safety factors compared to limit equilibrium, while on the other hand, the remaining two failure mechanisms shows the different result, with the finite element method obtaining lower safety factors than limit equilibrium. Modelling seismic load as an accelerogram indicates that earthquakes have higher impacts on structure stability compared to seismic coefficient, based on seismic safety factor reduction of each method. Although show differences in the value of the safety factor, the minimum safety factor required still complies with both methods.

Seismicity and return period investigation of destructive earthquake in Makran subduction zone

This work uses the frequency-magnitude relation for the earthquakes to analyze seismicity and return period for the earthquakes in Makran subduction and its adjacent region. The data for seismicity analysis and return period range from 1934 to 2022, with moment magnitude and depth ranging from 4.0 to 8.1 and 0 to 115 km. The b-values for eastern and western Makran are obtained by the maximum likelihood technique of 0.7 ± 0.04 and 0.764 ± 0.04, respectively. The temporal decrease of the b-value of the eastern and western vicinities of Makran suggests that stress levels in both regions are increasing, indicating potential big earthquakes may occur subsequentially. Similarly, the spatial variation of the b-value also suggests that stress in both areas is increasing. Notably, the change in the b-value is inversely proportional to the stress level in the region. If the stress level increases, the b-value decreases, and vice versa. The earthquake return periods with magnitude 5 and 5.5 vary from 1 to 2.7 and 2 to 8 years, and magnitude 6 and 6.5 vary from 5 to 30 and 10 to 60 years, respectively. The earthquake return periods with magnitude 7 and 7.5 vary from 20 to 120 and 50 to 300 years, and magnitude 8 and 8.5 range from 100 to 600 and 200 to 1200 years, respectively. The finding demonstrates that both the eastern and western vicinities of the Makran fault zone have high tectonic stress, and significant big earthquakes may occur in the future.

Analisis Bencana Longsor akibat Gempa bumi Cianjur 2022 dengan DInSAR

Indonesia is a country with a high potential for disasters such as earthquakes, which usually cause changes in the shape/position of the earth's surface (deformation). The Cianjur area has a seismic vulnerability level value based on maximum ground acceleration, maximum intensity and earthquake return period. On Monday, November 21, 2022 at 13.21 WIB there was an earthquake with a magnitude of 5.6 M in the Cianjur area of West Java based on BMKG data, until November 22, 2022 there were 140 aftershocks with magnitudes of 1.2-4.2 and an average depth of approximately 10 km. As a result, causing subsidence, the purpose of this study is to determine the magnitude of subsidence in landslides due to the 2022 Cianjur earthquake using the DInSAR method. Vertical land subsidence (displacement data) due to the earthquake from DInSAR observations on displacement data, which ranged up to -101mm vertically with two soil types andosol and cambisol Overlay analysis of soil type and displacement data showed the highest area of displacement, found a match based on information circulating that Cugenang Sub-district is the most severely affected area (the existence of a new fault "Cugenang").

Evaluation Of The Impact Of Liquefaction Potential On The Construction Of The Solo - Yogyakarta - NYIA Kulon Toll Road

Abstract The Solo - Yogyakarta - NYIA Kulon Progo Toll Road is one of the projects that aims to improve road network connectivity between Central Java and Yogyakarta. Liquefaction occurred in Yogyakarta after the 2006 earthquake, characterized by sand boiling and lateral spreading. This research was conducted to analyze the potential of liquefaction and evaluate the impacts that occur after liquefaction. The analysis of liquefaction potential uses the method developed by Idriss and Boulanger (2008), the maximum peak ground acceleration value using the earthquake return period of 100 years, 250 years, 1000 years, 2500 years, 5000 years, and 10000 years. Post-liquefaction analyses were conducted by calculating ground settlement developed by Yoshimine et al. (2006) and lateral displacement designed by Zhang (2004). The effect of liquefaction on bored pile foundations was assessed by comparing conditions without liquefaction and with liquefaction. The analysis showed 13 potential liquefaction borehole points with low - high liquefaction susceptibility levels. Post-liquefaction analysis shows that liquefaction can cause 0 cm - 27.32 cm settlement and lateral displacement of 0 cm - 199.24 cm.

Seismic evaluation and retrofit of a typical reinforced concrete hospital building in Indonesia with DCFP isolation system

In this paper, a study on seismic evaluation and retrofit of a typical reinforced concrete (RC) hospital building in Indonesia is presented. Seismic evaluation is performed against basic structural performance objectives outlined in the current code for structural seismic evaluation. The target building is a typical 5-story RC building designed by the 1970s Indonesia seismic and building codes, which imposed lower seismic demand and were not as strict as the current codes in the requirements for strength and ductility. The first part of the paper describes a seismic evaluation procedure against specific target performance levels. Nonlinear time history analysis (NLTHA) is conducted and structural performances were evaluated against structural responses (base shear force and inter-story drift ratio) and acceptance of seismic performance level for local (element rotational limit) and global (roof drift ratio) performance criteria under 225, 975, and 2475-year return period earthquake scenarios. Results reveal that seismic performances of some structural elements are unsatisfactory and under the acceptable performance level, especially for 2475-year return period (BSE-2 N/MCER) earthquake scenario. Seismic retrofit is thus recommended and the use of double-concave friction pendulum (DCFP) base-isolation system as a retrofit strategy is explored. The seismic performance of DCFP-retrofitted building is examined by NLTHA, where effectiveness of DCFP base-isolation system in improving seismic performance is confirmed by comparing structural responses, local and global structural performance of the existing building and the DCFP-retrofitted building under 2475-year return period earthquake scenario. Results of NLTHA demonstrate that local structural performance level has improved from Collapse Prevention to Immediate Occupancy level, whereas the global structural performance has improved from Limited Safety level to Operational level.

Influence of spatial variability of soil shear-wave velocity considering intralayer correlation on seismic response of engineering site

Shear-wave velocity uncertainty significantly impacts seismic response analysis at engineering sites. Previous studies focused on the correlations of shear-wave velocities within soil layers. However, the influence of the vertical spatial variability of shear-wave velocity within individual soil layers was not considered. This study selected a typical Site Class II engineering site to investigate this influence based on the equivalent linear seismic response analysis method of layered soil deposits. Existing field test data on shear-wave velocity were used to discretize the shear-wave velocity within soil layers into a one-dimensional (1D) random field through covariance matrix decomposition and local average process theory. Monte Carlo simulations generated random shear-wave velocity profiles with different vertical correlation distances. Three artificial records with different earthquake return periods were used as input motions at the engineering bedrock for the 1D free-field model. Considering soil shear-wave velocity uncertainty, the peak shear strain increased by 19–27% with the input ground motion amplitude. Moreover, the site peak shear strain variability increased by 25–34% with the vertical correlation distance. The proposed 1D random field model effectively simulated the interlayer correlation and spatial variability of shear-wave velocity within soil layers, demonstrating its significance in seismic response analysis.

Potential deformation assessment of Semantok Main Dam in North Nganjuk Region at East Java Indonesia

Semantok Dam was constructed using a zone l embankment type and required safety measures for deformation control. This study aims to understand material specifications, geological conditions, and deformation behavior. The results of the material specifications indicate that the core material and fine filter material meet the design criteria. The geological conditions comprise sand, sandstone, and claystone. The rock’s bearing capacity and settlement in the core zone are considered safe. The elastic vertical deformation of the foundation, analyzed using a flexible foundation approach by Lord, is estimated to be between 4.36 and 6.10 cm. Dynamic analysis is also performed using the Plaxis 8.6 version software to estimate deformation. The software input includes soil properties from the borrow and quarry areas surrounding the dam site. Earthquake design criteria are based on the Operating Basis Earthquake (OBE) with a 100-year return period and the Maximum Design Earthquake (MDE) with a 10,000-year return period. The dynamic analysis results indicate that the maximum deformation during a 100-year return period earthquake is 7.37 cm (horizontal deformation) and 12.68 cm (vertical deformation). In the case of a 10,000-year return period earthquake, the maximum deformation is 83.41 cm (horizontal deformation) and 175 cm (vertical deformation) during rapid drawdown.

Seismic cycle controlled by subduction geometry: novel 3-D quasi-dynamic model of Central Chile megathrust

SUMMARY Subduction earthquakes show complex spatial and temporal rupture patterns, exhibiting events of varied sizes, which rupture distinct or overlapping fault segments. Elucidating first-order controlling conditions of rupture segmentation and return periods of large earthquakes is therefore critical for seismic and tsunami hazard estimations. The Chilean subduction zone frequently hosts several Mw > 8 earthquakes, with heterogeneous recurrence rates and locations. Here, we implement 3-D quasi-dynamic rate and state frictional models to investigate the role of plate interface geometry on the distribution of interseismic coupling and coseismic ruptures in Central Chile. First, we develop synthetic-parametric models that show how dip and strike variations may increase the probabilities to produce partial seismic barriers, which tend to avoid the production of large earthquake ruptures and modulate rupture lengths. Then, we simulate the subduction seismic cycle processes on Central Chile (25°S–38°S), imposing depth-dependent frictional properties on a realistic non-planar 3-D subduction interface geometry. Similar to results obtained for synthetic-parametric models, after 5000 yr of simulation, regions with abrupt dip or strike changes increase the probabilities of stopping coseismic propagation of simulated Mw 8.0–9.0 earthquakes. Our simulated earthquake sequences on the Central Chile subduction zone delimit rupture areas that match geometrical interface features and historical earthquakes, results that point to the crucial role of fault interface geometry on seismic cycle segmentation along strike.

Tsunami Modeling Study in Geological Disaster Mitigation in the Kwandang Region

The northern coast of the northern arm of Sulawesi is the meeting place of 3 plates that collided with each other during the Neogene period. This condition makes the northern part of Gorontalo, especially Kwandang sub-district, very prone to earthquakes with magnitudes above 6 on the Richter scale (SR), which is one of the triggers for tsunamis. In the period from 1990 - 2008, there were 4 major earthquakes recorded in Gorontalo, namely 1990 (7.3 SR), 1991 (7.1 SR), 1997 (7.0 SR) and 2008 (7.7 SR). Therefore, further research is needed on the return period of the earthquake and the tsunami model that occurs and the sign of tsunami occurrence in the past. This research aims to determine the return period of the earthquake that caused the tsunami and the tsunami model as well as the sedimentology analysis of paleotsunami deposits. The calculation of the earthquake return period uses the Guttenberg-Richter method. Modeling calculations were carried out using the COMCOT numerical model. This model performs calculations by solving shallow water equations in the form of both linear and non-linear equations. Paleotsunami deposits were analyzed using the sedimentology method. The results of the calculation at a magnitude of 6.0 SR show that within 100 years, the study area has a chance of a potentially destructive earthquake of 1.14024978. The results of modeling the tsunami-prone zone, obtained an area of 165.598389 ha. And obtained paleotsunami deposits containing foraminifera with a sediment thickness of 14 cm.

Analysis of return period and seismic risk of Shallow Earthquake occurrence in Cianjur and surrounding areas

Determination of the seismic risk and return period of shallow earthquakes in Cianjur and surrounding areas is very important as a reference in earthquake disaster mitigation programs. Within this return period, structural and non-structural conditions can be prepared in stages that are ready to face disasters if the earthquake recurs. In this study used the least squares statistical method to determine the relationship between frequency and magnitude, level of risk, and earthquake return period. The earthquake data used in this study is sourced from the earthquake catalog of the United States Geological Survey (USGS) spanning 50 years (1973 – 2023). A total of 57 shallow earthquakes that occurred in Cianjur area and its surroundings at coordinates (06°-08°S and 106°-108°E) with magnitude greater or equal to 5.0 at a depth of 0-60 km were used as sample data. Based on the results of data processing and analysis, the return periods are 3.17 to 29.1 years for earthquakes with magnitudes between 5.0 and 6.0, and 29.1 to 267.38 years for earthquakes with magnitudes between 6.0 and 7.0.. Earthquake risk for 10 to 20 years with magnitude greater than 5.0 is 95.74 to 99.82 %, with magnitude greater than 6.0 is 20.09 to 49.70 %, and with magnitude 7.0 is 3.67 to 7.21 %. From the results of processing and analysis of the earthquake data, it shows that the Cianjur area and its surroundings are earthquake-prone areas with a high risk.

The seismic hazard from the Lembang Fault, Indonesia, derived from InSAR and GNSS data

Abstract. A growing number of large cities are located near poorly understood faults that have not generated a significant earthquake in recent history. The Lembang Fault is one such fault located near the city of Bandung in West Java, Indonesia. The slip rate on this fault is debated, with estimates ranging from 6 to 1.95–3.45 mm yr−1, derived from a GNSS (global navigation satellite system) campaign and geological measurements respectively. In this paper we measure the surface deformation across the Bandung region and resolve the slip rate across the Lembang Fault using radar interferometry (InSAR – interferometric synthetic aperture radar) analysis of 6 years of Sentinel-1 satellite data and continuous GNSS measurements across the fault. Our slip rate estimate for the fault is 4.7 mm yr−1, with the shallow portions of the fault creeping at 2.2 mm yr−1. Previous studies estimated the return period of large earthquakes on the fault to be between 170–670 years. Assuming simplified fault geometries and a reasonable estimate of the seismogenic depth we derive an estimated moment deficit equivalent to magnitude 6.6–7.0 earthquakes, indicating that the fault poses a very real hazard to the local population. Using the Global Earthquake Model OpenQuake engine we calculate ground motions for these two earthquake scenarios and estimate that 1.9–2.7 million people within the Bandung metropolitan region would be exposed to ground shaking greater than 0.3 g. This study highlights the importance of identifying active faults, understanding their past activity, and measuring the current strain rates of smaller crustal active faults located near large cities in seismic zones.

Analysis of Seismotectonic Parameters and Earthquake Return Periods in The Nias Area (1980-2021)

The Nias Islands region is an area prone to earthquakes with a very high level of earthquake activity. One reason is the source of the subduction zone which is in the northwest of the Nias Islands. The aim of this work is to determine the b-value, seismic index, and earthquake return period using probabilistic techniques. For the years 1980 to 2021, the Meteorology, Climatology and Geophysics Agency (BMKG) published data with a magnitude of 3-6.7 and a depth (H) of 10-300 Km. The research results obtained by calculating the highest b-value is 0.791 in South Nias district and the highest a-value is in the South Nias district of 3.97. Calculation of the highest seismicity index with a magnitude of 6.7 in South Nias district with a-value of 7.223191 with an earthquake return period of 14 years.

Earthquake Risk Potential Caused by Active Faults in Sumatra (Case Study: Earthquakes in the Land of West Sumatra Province and its vicinity)

The land of West Sumatra province is one of prone area stricken by the destructive earthquakes. Based on historical records, the land of West Sumatra province has a high seismic risk related to the earthquake events along active faults, such as the Sianok, Barumun, Sumani, Siulak and Angkola faults. Some destructive earthquakes occurred in these faults and caused fatalities in West Sumatra area and its vicinity, e.g., the earthquakes near Bukit Tinggi district in 1926, 1977, 2007 (doublet earthquakes-Tabel 1) and 2022. A previous study shows that the Sumani, Siulak, Sianok, Barumun and Angkola faults has a potential magnitude 7.1-7.7, a geodetic slip-rate of 6-14 mm/y respectively and these move generally strike slip. Using these magnitude scenarios to make the earthquakes impact modelled, we find the maximum intensity is about of VII-VIII MMI scale, the Peak Ground Acceleration (PGA) is about of 42-64 % g, and Peak Ground Velocity (PGV) is about of 30-50 cm/s for the assumption of 5-15 km hypocentral depth. Also with using the scaling law relation of earthquake parameters and magnitude scenarios the earthquake return period can be calculated by a kinematic model with the source mechanism was modelled as a strike slip faults. Estimation of the earthquake return period with magnitude (Mw) scenarios about 7.1-7.7 for these active faults is about of 114 until 612 years for strike slip model respectively. This method can be developed to make identically assessment for others active fault in Sumatra region and the result can be used as one of a consideration to support of planning of the long term landscape in the prone of earthquakes area.

Seismic Performance Evaluation of Wharf Based on ASCE 61-14

The adequacy of the structural performance of a wharf in withstanding seismic loads is of paramount importance. Therefore, this research aims to conduct an accurate pushover analysis on the adequacy of a wharf located in North Sulawesi, Indonesia. The study provides a comprehensive overview of the seismic performance of the wharf by examining displacement and strain parameters of its plastic hinge components under various loading conditions. To simulate accidental torsion, the wharf structure was analyzed by introducing variations in the eccentricity offset of the lateral pushover load of -5%, 0%, and 5% from the center of mass. The analysis of the torsion behavior involved a comprehensive examination of four control points located at each corner of the wharf plan. Additionally, the investigation took into account, the crucial aspect of soil-structure interaction by considering the equivalent fixity depth of the pile, which was used to evaluate the fixity length of the structure. In order to determine the target displacement of the wharf, analysis was performed in accordance with the established methodologies outlined in FEMA 356. It is also important to note that the seismic performance of the wharf was evaluated based on acceptance criteria in the form of strain limits imposed on various components, including concrete elements, reinforcing steel, and steel pipes, as prescribed by ASCE 61-14. In this study, a total of 30 models were examined, and the obtained results showed that the structure exhibited controlled and repairable damage even when subjected to a 475-year earthquake return period (CLE: Contingency Level Earthquake). Following this, the analysis of variations in displacement control point served to determine the inherent torsion exhibited by the structure, and the introduction of different lateral load eccentricity offsets and variations in pushover loading direction were found to contribute to the increased displacement and strain in the plastic hinge components.

Analysis of the Effect of Seismic Loads on Residential RC Buildings using the Change in Building Size and Return Period

Unlike a completed building, a building under construction may be at risk in terms of safety if a load exceeds the value considered in the design stage owing to various factors, such as a load action different from that in the design stage and insufficient concrete strength. In addition, if an earthquake occurs in a building under construction, greater damage may occur. Therefore, this study studied example models with various sizes of 5, 15, 25, and 60 floors for typical building types and analyzed the effects of seismic load on buildings under construction using construction-stage models according to frame completeness. Because the construction period of the building is much shorter than the period of use after completion, applying same earthquake loads as the design stage to buildings under construction may be excessive. Therefore, earthquakes with a return period of 50 to 2,400 years were applied to the construction stage model to review the seismic loads and analyze the structural performances of the members. Thus, we reviewed whether a load exceeding that of the design stage was applied and the return period level of the earthquake that could ensure structural safety. In addition, assuming the construction period of each example model, the earthquake return period according to the construction period was selected, and the design appropriateness with the selected return period was checked.

Seismic Rigoletto: Hazards, risks and seismic roulette applications

Neo-Deterministic Seismic Hazard Assessment (NDSHA), dating back to the turn of the Millennium, is the new multi-disciplinary scenario- and physics-based approach for the evaluation of seismic hazard and safety–guaranteeing “prevention rather than cure.” When earthquakes occur, shaking certainly does not depend on sporadic occurrences within the study area, nor on anti-seismic (earthquake-resistant) design parameters scaled otherwise to probabilistic models of earthquake return-period and likelihood — as adopted in the widespread application of the model-driven Probabilistic Seismic Hazard Analysis (PSHA). Therefore, from a policy perspective of prevention, coherent and compatible with the most advanced theories in Earth Science, it is essential that at least the infrastructure installations and public structures are designed so as to resist future strong earthquakes. Evidences and case histories detailed in the newly published book Earthquakes and Sustainable Infrastructure present a new paradigm for Reliable Seismic Hazard Assessment (RSHA) and seismic safety — comprehensively detailing in one volume the ‘state-of-the-art’ scientific knowledge on earthquakes and their related seismic risks, and actions that can be taken to ensure greater safety and sustainability. The book is appropriately dedicated to the centenary of Russian geophysicist Vladimir Keilis-Borok (1921–2013), whose mathematical-geophysical insights have been seminal for the innovative paradigm of Neo-deterministic seismic hazard assessment. This review focuses on Hazards, Risks and Prediction initially discussed in the introductory Chapter 1 — an understanding of which is essential in the applications of the state-of-the-art knowledge presented in the book’s 29 following chapters.

Estimating the recurrence of earthquakes with statistical methods in the city of Bingöl, Eastern Turkey: a district-based approach

This study discusses the temporal distribution of earthquake magnitudes in the city of Bingöl, near Karlıova Triple Junction. We determine the probability distributions and return periods of earthquakes for all districts of Bingöl. Bingöl has eight districts; namely Adaklı, Central, Genç, Karlıova, Kiğı, Solhan, Yayladere, and Yedisu. In six of them, active faults were mapped previously (Adaklı, Central, Genç, Karlıova, Solhan, and Yedisu). We consider 5 time-dependent probability distributions for analysis. Using the annual maximum earthquake magnitudes, the best fit arises from the Gumbel distribution for Central, Karlıova, and Adaklı Districts. For the Genç District, where the least maximum earthquake magnitude is reported, the Weibull distribution gives the best fit. The return period and maximum annual earthquake magnitude relations suggest the following results. For the Central and Karlıova Districts along which maximum earthquake magnitudes are reported, every 250 years a 6.7 M, and 7.2 M occurs respectively. These results are compatible with the results of paleo-seismological data reported along the NAFZ and the EAFZ. For a 10-year return period, earthquake magnitudes reach 3.9 and 5.1 in all districts. It is important to note that in the Yedisu District, the maximum earthquake magnitudes seem as 5.1 M for the 1000-year return period, incompatible with previously published findings probably because low quality seismic data in this region.