Temporal and spatial seismic risk scenarios of Istanbul

V1.0 – November 28th, 2024 Final version: https://doi.org/10.1080/13669877.2025.2522667 To cite this article: Kundak, S., Göksu, Ç., Arslanlı, K. Y., Aşıcı, A. A., Yılmaz, A., Kalkanlı, D., … Pak, E. Ö. (2025). Temporal and spatial seismic risk scenarios of Istanbul. Journal of Risk Research, 1–16. https://doi.org/10.1080/13669877.2025.2522667 Temporal and Spatial Seismic Risk Scenarios of Istanbul Seda Kundaka*, Çağlar Göksub, Kerem Yavuz Arslanlıa, Ahmet Atıl Aşıcıc, Ali Yılmaza, Duygu Kalkanlıa, Cihan Mert Sabaha, Betül Ergün Konukçud, Ece Özden Pakd aDepartment of Urban and Regional Planning, Istanbul Technical University, Istanbul, Türkiye; bDisaster Management Institute, Istanbul Technical University, Istanbul, Türkiye; cDepartment of Management Engineering, Istanbul Technical University, Istanbul, Türkiye; dIstanbul Metropolitan Municipality, Istanbul, Türkiye. * Seda Kundak [email protected] (corresponding author) Temporal and Spatial Seismic Risk Scenarios of Istanbul Istanbul is an earthquake-prone megacity due to its proximity to the North Anatolian Fault. Historical events such as the 1999 Kocaeli and 2023 Kahramanmaraş earthquakes have demonstrated the probable risks which Istanbul is facing aligned with its exposure and vulnerabilities at different levels. This study aims to evaluate Istanbul's seismic risks through six different scenarios, integrating both temporal and spatial dimensions to provide a comprehensive understanding of risk reduction and disaster preparedness. Using the Impact Chains (IC) methodology, the study examines the immediate, short-term and long-term impacts of earthquakes occurring at different times and under different conditions. Scenarios range from a winter evening with heavy traffic to a summer weekday afternoon in tourist-heavy areas. Key findings highlight critical challenges in communications, infrastructure and emergency response, and emphasize the need for robust disaster management strategies. This study underscores the importance of a multi-faceted approach to earthquake risk management in megacities and provides valuable insights for policy makers, urban planners and disaster management professionals to reduce risks and increase resilience in Istanbul. Keywords: earthquake, risk assessment, systemic risks, urban mobility Subject classification codes: include these here if the journal requires them 1. Introduction Istanbul, a megacity of more than 15 million inhabitants, is highly exposed to seismic activity and cascading hazards such as liquefaction, landslide, inundation, fire, and tsunami. The city also faces increasing hydro-meteorological hazards, including extreme temperatures, fires, and floods, further complicating the overall risk profile. Rapid population growth, combined with rapid urban expansion, internal migration and mass immigration from Middle Eastern countries, along with the inadequacy of integration policies, have led to the formation of new vulnerable communities, increasing uncertainties and unpredictability in social conditions and needs, further complicating the city's risk profile, creating additional layers of vulnerability that must be addressed in risk assessments. The significant income and wealth gap between socio-economic groups adds another layer of vulnerability, as the poorest and most marginalized communities are often the most affected by disasters. Despite Istanbul's critical importance to the national economy, its vulnerabilities might have consequences beyond its borders. Disruptions in Istanbul can propagate through various channels and affect other cities and regions. Therefore, understanding and mitigating Istanbul's seismic risks is critical not only for the city itself, but also for broader geography. Consequently, this study aims to address the earthquake risk of Istanbul with a more comprehensive and multidimensional approach. This study adopts a broader perspective by incorporating socio-economic factors, mobility, and cascading effects, thus accounting for the entire urban dynamic. This comprehensive approach ensures that overlooked aspects, such as urban mobility during different phases of an earthquake, are thoroughly considered. By integrating spatiotemporal modeling, scenario-based analysis, impact chains, and participatory tabletop workshops, this research bridges gaps found in traditional assessments through a stakeholder-driven analysis of potential earthquake impacts. The spatio-temporal approach reveals how risks evolve over time and throughout Istanbul's diverse urban landscape, while incorporating mobility and social dynamics enhances our understanding of how human behavior, transportation systems, and economic activities interact during and after an earthquake. The scenario-based analysis further investigates potential outcomes under various conditions, such as different times of the day, seasons, and varying population densities, which all influence vulnerability. The impact chain method maps relationships between risk factors, capturing both direct impacts and cascading effects like infrastructure failures and economic disruptions. Participatory tabletop workshops involving stakeholders from multiple disciplines ensure that context-specific, practical realizations are incorporated, making this study uniquely suited to addressing Istanbul's complex seismic risk profile. 2. Background of the study Seismic risk refers to the potential consequences of earthquakes, combining both the probability of an event and the severity of its impacts. Seismic risk assessments have focused primarily on physical damage to buildings and infrastructure, that predict impacts based on ground motion and structural vulnerability. While this provides valuable comprehension into potential damages, it often overlooks broader socio-economic disruptions, cascading effects, and urban systems. Conventional approaches provide a solid foundation for understanding immediate, direct risks but are limited when it comes to more complex interactions in a densely populated and economically diverse urban environment where factors such as mobility play a crucial role (Carpignano et al. 2009; Maio et al. 2016; Silva et al. 2020). More comprehensive methods in seismic risk assessment have introduced dynamic, probabilistic, and scenario-based approaches, which extend beyond immediate physical impacts and include secondary risks arising from complex interactions between systems like infrastructure, social services, and economic activities (Chang, Shinozuka, and Moore 2000; Klügel, Mualchin, and Panza 2006; Oynakov et al. 2023; Rajput, Jakka, and Sinvhal 2023; Rohmer and Baudrit 2011; Schroeder and Lambert 2011). These models evaluate diverse earthquake scenarios and associated risks, from structural failures to secondary disasters. Despite these advancements, they often focus on limited factors and may not fully capture the complexities of interrelated risks that can amplify the effects of a disaster. The 2004 Sumatra earthquake, which occurred on the Christmas break, had a greater-than-expected impact due to its timing, as several tourists from different countries were enjoying holidays in the earthquake-hit zone, which complicated rescue and response activities. In the case of the 2023 Kahramanmaraş earthquakes, the first earthquake occurred on February 6th at 04:17 in local time while people were sleeping. The harsh winter condition caused great challenges for both earthquake victims and search and rescue teams. Kocaeli earthquake occurred on August 17th in 1999, at 03:02 in local time in which the summer conditions did not add any additional burden to the post-disaster process compared to the 2023 Kahramanmaraş earthquakes. These examples highlight the importance of incorporating the temporal dimension into seismic risk assessment to understand dramatic shifts in these effects. While physical damages may remain consistent in each scenario, the following effects can vary significantly depending on the timing of the event, affecting emergency response effectiveness and overall societal impact. Furthermore, these examples demonstrate the importance of a comprehensive and multidimensional approach to seismic risk assessment that includes temporal and spatial perspectives. Scenario-based approaches are therefore crucial for capturing these temporal and spatial variations, ensuring a more holistic understanding of seismic risks and enabling more effective disaster management planning. 2.1. Present Vulnerabilities of Istanbul Istanbul is located near the North Anatolian Fault, one of the most active and potentially destructive fault lines in the country, with significant seismic events in the past such as the 1999 Kocaeli and 2019 Silivri earthquakes in the recent decades. The fault runs under the Sea of Marmara, posing a constant threat not only of seismic activity but also of tsunami hazard that would severely affect coastal areas. The proximity of this fault line to a major metropolitan area increases the potential for devastating earthquakes that could cause significant loss of life and property (Ambraseys and Jackson 2000; M. Erdik et al. 2003; Parsons et al. 2000). Istanbul's rapid urbanization has resulted in a densely populated urban environment with a mix of modern high-rise buildings and historic structures (Aydogdu et al. 2024). The city's population exceeds 15 million (Turkish Statistical Institute 2023), with many residents with a significant share of residential areas concentrated along the Marmara Sea coast, which is close to the fault line. The building stock varies widely in age and construction quality, with approximately 70% constructed before the revised building regulations introduced after the 1999 Kocaeli earthquake, indicating that many buildings predating 2000 remain highly vulnerable (Istanbul Metropolitan Municipality 2019). While newer buildings are generally constructed to higher standards, many older buildings do not meet modern seismic codes. The inconsistent application of building codes and the presence of informal settlements further exacerbate the city's vulnerability to seismic events (Mustafa Erdik and Durukal 2008). According to the microzonation report which had been prepared by Japan International Cooperation Agency (JICA) and Istanbul Metropolitan Municipality (IMM), Istanbul's infrastructure, including transportation networks, utilities, and communication systems, is critical to the functioning of the city but is highly vulnerable to seismic activity (JICA and IMM 2002). The aging infrastructure, along with the dense urban fabric, poses significant challenges for emergency response and evacuation. While infrastructure built after 2000 has been reinforces or newly constructed to account for seismic threats, the rapid population growth and increased mobility have led to an overburden on transportation and infrastructure systems. Key infrastructure elements such as bridges, tunnels, and power lines remain at risk of severe damage during an earthquake, with particular emphasis on logistics and transportation networks, which are crucial for effective emergency response and continuity of supply chains The socio-economic landscape of Istanbul is characterized by significant inequalities in income and living conditions (Keyder 2005). Low-income areas often suffer from inadequate urban infrastructure, and, since the 1980s, neoliberal policies have driven irregular migration to Istanbul, resulting in unplanned settlements. Vulnerable communities, including low-income households, migrants, and informal settlers, are affected more than average by seismic risks due to their limited access to resources and inadequate housing. The economic impact of an earthquake would also be significant, given Istanbul's role as an economic hub. Disruptions to business operations, loss of jobs, and damage to critical economic infrastructure would have far-reaching consequences not only for the city, but for the entire country. Furthermore, along with the comprehensiveness of Istanbul's current situation, there are seismic risk studies on the city. Seismic risk assessments in Istanbul have focused on estimating potential damage to infrastructure, with Erdik et al., (2003) conducting a comprehensive study that quantified the earthquake risk for the metropolitan area. Further research has highlighted the varying perceptions of risk among Istanbul’s residents, indicating that socio-economic factors significantly influence earthquake preparedness (Eraybar et al., 2010; Kundak, 2017). Efforts to mitigate risks have been inconsistent, with critiques pointing out the challenges in implementing large-scale earthquake risk reduction strategies in such a complex urban setting (Ay and Demires Ozkul 2021). Additionally, specific concerns have been raised regarding the preparedness of vulnerable populations, such as children in schools, emphasizing the need for targeted educational initiatives to improve resilience (Ersoy and Koçak 2016). Collectively, these studies underline the necessity for a multifaceted approach to seismic risk management, encompassing structural assessments, public awareness, and policy implementation (Pyper Griffiths, Irfanoglu, and Pujol 2007). 2.2. Historical Context with Lessons for Istanbul The historical context of seismic activity in Türkiye reveals a critical understanding that informs the scenario development in this study. By examining significant earthquakes such as the 1939 Erzincan, 1999 Kocaeli, 2011 Van, 2019 Silivri, and 2023 Kahramanmaraş events, it becomes evident how both spatial and temporal dimensions influence the magnitude and complexity of impacts (Figure 1). These historical earthquakes not only illustrate the devastating primary effects of seismic activity but also emphasize the importance of addressing secondary risks, including industrial hazards, cascading effects of poor infrastructure, and socio-economic disparities. This section explores these events in detail, providing a foundational understanding that supports the comprehensive risk assessment framework adopted in the present study. Figure 1. Major earthquakes in Turkey in the last 100 years, underlying the scenarios. 1939 Erzincan earthquake The 7.9 magnitude earthquake that struck Erzincan on December 27, 1939, was one of the most devastating in Turkey's history. Approximately 33,000 people lost their lives, and over 100,000 were injured. The winter conditions, including heavy snowfall and low temperatures, severely hampered rescue operations and led to widespread road closures. More than 116,000 buildings were destroyed or heavily damaged (Ministry of Interior Disaster and Emergency Management Presidency 2021). This earthquake exposed the critical seismic vulnerabilities in Turkey and prompted the first legal steps toward earthquake-related regulations. 1999 Kocaeli earthquake On August 17, 1999, a 7.4 magnitude earthquake struck the Gölcük/Kocaeli region, causing widespread devastation. Official records indicate that 18,373 people lost their lives, 48,901 were injured, and nearly 97,000 homes and 16,000 workplaces were either destroyed or severely damaged (Grand National Assembly of Turkey 2010). The disaster left 250,000 people homeless, with many relocating to neighboring towns. Damage was exacerbated by low-quality construction, poor site selection, and inadequate building practices. The TUPRAS oil refinery disaster highlighted the vulnerability of industrial facilities, causing fires and hazardous material releases (Cruz, Steinberg, and Arellano 2004; Scawthorn, Eidinger, and Schiff 2005; Steinberg and Cruz 2004). 2011 Van earthquake On October 23, 2011, a magnitude 7.1 earthquake struck Van, killing over 600 people and injuring about 2,000. The earthquake highlighted the vulnerability of rural buildings due to poor construction materials, inadequate engineering inspections, and unplanned development. The eastern region's limited disaster response capacity compared to the west further complicated rescue efforts. The quake occurred during the daytime on a weekend, reducing casualties since many people were outside. However, the damage to poorly constructed buildings in rural areas was extensive, demonstrating the critical need for improved building standards and emergency response capabilities. produced by the workshop participants regarding the impact chains for six scenarios have been summarized under two categories: “scenario-based challenges” and “common challenges / responses” (Figure 3). According to the IC diagrams produced for each scenario, it had been observed that the scenario-based challenges mostly refer the first 72 hours as they add obstacles basically to search and rescue activities. Figure 3. Evaluation of the six scenarios 4.1. Scenario-based challenges Scenario 1: Fall/Winter evening On a rainy day between 18:00-19:00 on weekdays, an earthquake with a magnitude greater than Mw7.0 occurs on the North Anatolian Fault. This time coincides with a high level of mobility, as people are leaving work and heading home, while others are preparing for dinner. Traffic congestion during these hours may severely delay emergency response units and evacuation processes, further complicating rescue efforts. Although this scenario does not directly reference a specific historical earthquake, it draws from general insights gained from past seismic events, emphasizing the compounded risks associated with both high mobility and household density during week days. Scenario 2: Weekday midnight An earthquake with a magnitude greater than Mw7.0 occurs on the North Anatolian Fault during a weekday at midnight under normal weather conditions. This scenario emphasizes how nighttime conditions increase vulnerability by complicating rescue operations and delaying response efforts as experienced in both 1999 Kocaeli and 2023 Kahramanmaraş earthquakes. While traffic is minimal, allowing for quicker emergency assessment and response, a large population is at home, increasing potential residential casualties. Darkness and a sleeping population may delay initial response and self-rescue efforts, but reduced external activity can allow emergency services to navigate the city more efficiently once mobilized. Scenario 3: Weekend afternoon An earthquake with a magnitude greater than Mw7.0 occurs on the North Anatolian Fault on a weekend afternoon around 14:00-16:00. Favorable weather encourages people to spend time outside in recreational and commercial zones. This scenario is a simulation of the 2011 Van earthquake occurred at the weekend and midday when most people were outdoors. Population concentration is higher in central districts, as well as parks, shopping streets, and the Princes' Islands. Some inhabitants also spend weekends in the forest areas in Northern Istanbul, resulting in slow traffic flow due to high mobility. This highlighted the complexity of managing safety in open spaces during an earthquake, especially regarding crowd control and ensuring that public areas are prepared for seismic shocks. In this scenario, few casualties are expected as people are outside, but chaos and security problems will occur in central districts. Scenario 4: Weekend bad weather An earthquake with a magnitude greater than Mw7.0 occurs on the North Anatolian Fault during the weekend. Due to bad weather conditions, most people are expected to be home with their families, which poses unique challenge for emergency services, including reduced mobility for rescue teams and difficulty accessing affected areas. Adverse weather may affect road functionality beyond debris caused by the earthquake. This scenario highlights how adverse weather exacerbates post-earthquake challenges by hindering access and delaying emergency interventions, as experienced in both 1939 Erzincan and 2023 Kahramanmaraş earthquakes. Heavy rain, snow, or storms can impede mobility. The dual impact of severe weather and a seismic event places immense strain on need of shelter, emergency services and infrastructure. Scenario 5: Summer weekday afternoon An earthquake with a magnitude greater than Mw7.0 occurs on the North Anatolian Fault during July and August, weekdays between 1:00 PM and 4:00 PM. Parts of the city with low population and high tourist activity, mostly business and tourist areas, are affected. The historical peninsula, old city center, and surroundings are fully engaged with museums, old bazaars, historical buildings, and open-air activities. The typical weather makes it an ideal time for outdoor activities like walking and sightseeing. This scenario considers increased population density in tourist areas, emphasizing vulnerabilities and challenges for emergency response in crowded environments. Such an earthquake affects popular tourist destinations, historic sites, and business districts, likely causing significant disruption. The presence of many non-residents complicates evacuation and relief due to language barriers and unfamiliarity with the area. Scenario 6: Early morning week day An earthquake with a magnitude bigger than 7.0 occurs on the North Anatolian Fault in the early morning at 9 am, around the end of commuting time. The traffic load is slightly higher than the daily average, presenting significant emergency response and evacuation challenges. The working population is already at work, and students are at school, which complicates reunification efforts and puts a strain on public transportation systems. Weather conditions are considered normal without any extremes. The 2019 Silivri earthquake inspired this scenario, demonstrating the potential impacts of heavy morning traffic on emergency response, public transportation disruptions, and increased confusion during peak commuting times. This scenario demonstrates the potential impacts of morning traffic on emergency response, public transportation disruptions, and increased confusion during peak commuting times. Heavy traffic on major roads and public transportation systems can cause severe congestion, hampering emergency response and evacuation efforts. 4.2. Common challenges / responses In the initial hours following the disaster, it is expected that substandard buildings will experience extensive damage, leading to structural collapses and a significant number of casualties, particularly along the coastline. The risk of a tsunami is anticipated to further exacerbate the situation, obstructing major seaside roads and disrupting mobility. Mobile communication networks are likely to become inoperative, and widespread power outages are projected. Security concerns may arise due to potential fires and explosions triggered by damaged infrastructure. Within the first 24 hours, disruptions in water supply, communication, and energy are expected to pose severe challenges for both survivors and search and rescue operations. Accessibility is likely to be significantly hindered by road blockages caused by debris and damaged infrastructure, delaying evacuation and relief efforts. Communication issues are anticipated to persist until base stations can be re-established. National and international logistic support is expected to face substantial difficulties due to damaged transport routes and vehicles immobilized in traffic. During the first 72 hours, inadequate human resources are likely to impede emergency response efforts as search and rescue operations continue. It is estimated that approximately 100,000 buildings will sustain heavy damage, leaving around 3 million individuals in need of temporary shelter. The demand for basic goods, fuel, and equipment is expected to surge, further straining supply chains. Health services are likely to face overwhelming pressure due to the high number of injured individuals, and burial processes for casualties may become an additional logistical challenge. The evacuation process is anticipated to be accompanied by temporary migrations to other provinces. By the fifteenth day, migration from affected areas is expected to become unavoidable, driven by the risk of disease outbreaks and deteriorating living conditions. Psychological support services are likely to be deployed to address the mental health needs of affected populations. Temporary shelter centers are expected to be operational, although shortages of water and food may persist, intensifying the risk of epidemics. Social erosion and logistical problems are anticipated to escalate as resources are stretched thin. By the third month, debris removal is expected to continue alongside the gradual resumption of work and daily life. Temporary and permanent shelter shortages are likely to persist, contributing to increased economic difficulties and unemployment. The tourism sector is anticipated to experience significant declines due to damaged infrastructure and reduced visitor confidence. Production and employment losses are expected to further exacerbate economic challenges, while efforts to assess direct and indirect losses are likely to provide a clearer understanding of the disaster’s impact. In the medium term, spanning several months to a year, the reconstruction process is expected to progress, focusing on rebuilding critical infrastructure and housing. Economic challenges, including unemployment and reduced production, are anticipated to persist, reshaping the demographic and social structures of the city. Exposure to heavy metals and asbestos during debris removal is likely to pose long-term public health risks. Access to education and healthcare services is expected to remain limited, hindering recovery and resilience-building efforts. In the long term, the economic, social, and environmental consequences of the disaster are likely to continue affecting the region. Psychosocial impacts are anticipated to linger among survivors, and environmental degradation, including air pollution from reconstruction activities, is expected to pose additional challenges. Newly constructed, earthquake-resistant living spaces are projected to enhance urban resilience, although full economic recovery and a return to pre-disaster production levels are likely to require significant time and resources. Historical heritage sites are expected to sustain lasting damage, resulting in a prolonged decline in tourism and related revenues. 4.3. Spatial reflection of the six scenarios Istanbul is a vast and highly interconnected urban system that originally developed in a linear pattern, stretching from east to west. The construction of two bridges connecting the European and Asian sides of the city catalyzed urban sprawl northward, running parallel to the Bosphorus Strait. Today, the city’s macroform shows significant expansion on the European side, driven by the development of the new Istanbul Airport and improved connectivity through the North Anatolian Motorway. Despite Istanbul’s polycentric structure, which has been evolving since the 1990s, the dominance of the city core remains prominent, offering a wide range of urban facilities and hosting the headquarters of numerous national and international companies. This concentration contributes to long commuting times, further intensified by large industrial zones at the city’s fringes. These zones significantly increase transportation demands, not only for workers but also for heavy vehicles, adding to the city’s already high traffic volume. (Figure 4). Figure 4. Scheme of the Macroform of Istanbul The spatial analysis of the challenges presented in the six scenarios underscores the most vulnerable and critical zones within the city, emphasizing areas of heightened risk in the event of a disaster. Particularly, the dense spatial configuration of the city core, combined with its consistently high traffic volume, is poised to become a significant bottleneck, exacerbating logistical challenges and impeding emergency response efforts following an earthquake. This congestion is likely to hinder the mobility of rescue teams, delay the delivery of critical aid, and restrict evacuation routes, effectively creating a "trap" that magnifies post-disaster obstacles. In addition to these physical and logistical challenges, the likelihood of chaotic social conditions is high, as panic and confusion among citizens could escalate rapidly in the absence of clear guidance. The situation would demand a well-coordinated presence of security forces to maintain order, ensure public safety, and provide reassurance to an anxious population. This highlights the need for robust disaster preparedness plans, including traffic management strategies, designated evacuation routes, and trained personnel capable of managing both physical and social crises in the aftermath of such an event (Figure 5). Figure 5. Scheme of the scenario-based challenges of the six scenarios 5. Discussion The findings of this study underscore the critical role of temporal and spatial dimensions in formulating effective earthquake management strategies, particularly in a complex urban environment like Istanbul. By examining six distinct scenarios, the study has highlighted both unique and common vulnerabilities in the context of seismic risks, with an emphasis on the significant influence of factors such as timing, weather conditions, and infrastructure robustness. One of the major outcomes of this study is the emphasis on the first 72-hour threshold. During the initial 72 hours, scenario results show significant variations in the challenges faced and the effectiveness of emergency responses. Factors such as traffic congestion during peak hours, adverse weather conditions, and the time of day create difficulties for each scenario. However, beyond the first 72 hours, these differences begin to diminish, and the long-term recovery efforts converge across all scenarios. Common issues like migration, shelter needs, economic disruptions, and psychosocial support emerge as central themes, highlighting the need for a unified, long-term approach to urban resilience and recovery. The approach employed in this study is characterized by several methodologies: scenario-based analysis, Impact Chain (IC) framework, and participatory stakeholder tabletop exercises. Together, these elements provide a distinctive methodological contribution to the study. The scenario-based analysis allowed for a detailed exploration of how different variables (such as season, time of day, and weather) influence the outcomes of an earthquake. Spatio-temporal perspective provided an enhanced understanding of how impacts change over time and across different locations. The IC framework helped in mapping the cascading effects of initial disruptions, providing a systematic approach to understanding secondary risks. Moreover, the participatory tabletop workshops engaged diverse stakeholders, adding a practical, community-based perspective that enriched the analysis by integrating real-world expertise and concerns. This study stands apart from traditional seismic risk assessments in the literature due to its comprehensive, multi-faceted approach. Unlike conventional studies that predominantly focus on structural vulnerability and static risk assessments, this research incorporates socio-economic dynamics, human mobility, and cascading secondary effects into the analysis. This holistic perspective enables a more inclusive understanding of seismic risks, particularly in a megacity like Istanbul, where non-structural factors play a crucial role in determining the overall impact of an earthquake. The integration of community perspectives through participatory workshops further distinguishes this work by bridging the gap between technical assessments and societal needs. 6. Conclusion The study reveals that building Istanbul's resilience to seismic risks demands an integrated, multi-faceted framework. The most critical insight from this study is the need for a coordinated and inclusive long-term recovery approach that effectively addresses shared vulnerabilities, ensuring that Istanbul becomes safer and more resilient against future seismic threats. Without such a comprehensive strategy, the city remains vulnerable to recurring risks that could jeopardize both lives and economic stability. Despite the significant contributions of this study, several gaps and limitations should be addressed in future research. First, while the workshop engaged a diverse group of stakeholders, the inclusion of additional participants, such as community representatives, local businesses, and international experts, could provide further insights and perspectives on Istanbul's seismic risk management. Future studies could also explore the use of digital platforms and remote participation to facilitate broader stakeholder engagement. The study relies primarily on qualitative data and expert knowledge gathered during the workshop. While this approach provides valuable insights, future research could benefit from integrating more quantitative data and advanced modeling techniques to refine the scenarios and impact assessments. This could include the use of probabilistic seismic hazard analysis, vulnerability assessments, and economic loss modeling to provide more precise estimates of potential impacts and inform decision-making. The study focuses on six specific earthquake scenarios, which, while informative, may not Natural Hazards Review 5 (3): 121–30. https://doi.org/10.1061/(ASCE)15276988(2004)5:3(121). Turkish Statistical Institute. 2023. “Address Based Population Registration System Results.” https://data.tuik.gov.tr/Bulten/Index?p=Adrese-Dayali-Nufus-KayitSistemi-Sonuclari-2023-49684.