Shortly after 3 a.m. on 3 August, residents across Cairo, the Suez Canal cities and parts of the Nile Delta awoke to a tremor that lasted only seconds but was strong enough to send some people out of their homes and into the streets. Egypt’s National Research Institute of Astronomy and Geophysics (NRIAG) measured the earthquake at magnitude 5.6, located its epicentre about 38 kilometres north of Suez and estimated its depth at 10 kilometres. No deaths or widespread damage were initially reported. The Egyptian Red Crescent subsequently received reports of a collapsed balcony in Suez and partial damage to a building in Cairo’s Rod El-Farag district, from which three families were evacuated as a precaution. The Health Ministry recorded one minor injury. The modest losses, however, should not obscure the warning contained in the event. It raised a more consequential question about what might have happened had a similarly shallow earthquake occurred directly beneath a densely populated neighbourhood containing a larger concentration of old, poorly maintained or structurally altered buildings. A rift that has not stopped moving The Gulf of Suez lies at the northern end of the rift system associated with the opening of the Red Sea and forms, according to Sherif Elhady, head of NRIAG’s Seismology Department, one of the northern arms of a vast geological structure that began developing around 20–30 million years ago. Earth scientists have long debated whether the Suez Rift should be regarded as a failed rift or as a system that entered a largely inactive post-rift phase. A study published in Geophysical Research Letters in 2025 challenged the idea that extension had stopped entirely, estimating that the rift continues to widen at a slow rate of approximately 0.26–0.55 millimetres per year. While the rate cannot predict future earthquakes, it confirms that the crust is still deforming and accumulating stress. The preliminary focal-mechanism solution produced by the Egyptian National Seismic Network provides further context for the August event. According to Asem Salama, associate professor of environmental geophysics at NRIAG, the analysis indicates movement on a normal fault oriented roughly north-northwest to south-southeast, consistent with the extensional forces affecting the Suez Rift. A similar mechanism was identified in a recent analysis of a magnitude-5 earthquake that struck the western coast of the Gulf of Suez in December 2022, which researchers attributed primarily to normal faulting associated with continuing crustal extension. The epicentre of that earthquake was approximately 53 kilometres from another magnitude-5.1 event recorded in 2013, while Elhady places the August 2026 earthquake within the broader area containing both previous events, suggesting that the Gulf includes active fault belts capable of periodically generating moderate earthquakes. Their geographical proximity should not, however, be interpreted as evidence of increasing seismicity. Salama considers the 2013, 2022 and 2026 events consistent with the normal behaviour of a slowly deforming but active rift, rather than proof that earthquakes in the region are becoming more frequent. Why was the earthquake felt so widely? The earthquake’s shallow depth helped make it noticeable across a wide area because energy released close to the surface travels through less rock and undergoes less attenuation before reaching buildings. Damage, nevertheless, depends on more than depth, with distance, ground conditions, duration of shaking and construction quality all influencing the outcome. Salama notes that soft sedimentary soils in parts of Cairo, the Nile Delta and the Suez Canal cities can amplify seismic motion relative to competent rock because loose or unconsolidated deposits may move more strongly and prolong shaking within particular frequency ranges. A study published in Scientific Reports in 2026, which analysed thousands of waveforms from around 250 earthquakes in northeastern Egypt, identified variations associated with the earthquake source, the path followed by the waves and the response of individual recording sites. Its findings help explain how the same earthquake can produce markedly different levels of shaking at places situated at similar distances from its epicentre. Height alone does not determine vulnerability Sameh Mehanny, professor of structural engineering at Cairo University and a member of the technical committee developing Egypt’s seismic design code, cautions against assessing vulnerability solely through a building’s age or height because its structural system, seismic detailing, construction quality, configuration and underlying ground conditions are often more important predictors of performance. Structures of particular concern include unreinforced brick or stone buildings, older concrete frames lacking ductile detailing, buildings with open ground floors used for shops or parking, and structures characterised by irregular layouts or heavy overhangs. Low- and mid-rise buildings of between two and 10 storeys can be especially vulnerable when they pre-date modern seismic requirements or were constructed with poor materials and workmanship. Height alone, therefore, provides an unreliable measure of risk: a properly designed and constructed 30-storey tower can perform better during an earthquake than a poorly built three-storey masonry structure exposed to the same shaking. Shehata E. Abdel Raheem, vice dean for Graduate Studies and Research and professor of earthquake, structural and geotechnical engineering at Assiut University, points to another vulnerability that becomes especially important in Egypt’s densely developed neighbourhoods: the small or nonexistent gaps between adjacent buildings. Buildings that touch each other, or are separated by insufficient distance, may have been designed independently despite having different heights, stiffness and dynamic behaviour. During strong shaking, their movements can therefore fall out of phase, causing them to strike one another in a phenomenon known as seismic pounding. Such impacts can concentrate damage at particular floors or structural elements, especially where neighbouring buildings do not have matching floor levels. Research examining Egypt’s existing building stock supports broader concerns about structural configuration. A study of multi-storey reinforced-concrete buildings found that vertically irregular structures were more vulnerable than regular ones. Even an earthquake in the magnitude-5-6 range can therefore be destructive in a country with low-to-moderate seismicity because damage depends on the intensity of local shaking rather than magnitude alone. A shallow magnitude-5 event near a densely populated city containing vulnerable buildings on soft soil could cause more damage than a deeper magnitude-6 earthquake occurring farther away. Additional floors and unrecorded alterations Construction date represents only one element of seismic risk because changes made after a building is completed can substantially alter how forces move through its structure. Mehanny warns that additional storeys or loads not included in the original design may exceed the capacity of the structural frame and foundations, while removing or modifying walls, columns or beams without engineering analysis can weaken the systems that transfer earthquake forces through the building. Abdel Raheem adds that unauthorised additional floors can also change a building’s seismic behaviour in less obvious ways. Adding storeys increases its mass and can alter its stiffness, natural period and overall dynamic response. Where the altered building stands immediately beside another structure, those changes may also increase the likelihood or severity of pounding because the two buildings can begin to move differently during the same earthquake. Poor concrete, insufficient reinforcement, defective connections, corrosion and ageing materials can further increase vulnerability, even when the original design complied with the relevant code. An apparently sound design therefore offers limited assurance when construction was defective or when the structure was subsequently modified without professional review. From broad zones to city-level assessments Rashad Sawires, professor of applied geophysics at Assiut University and currently at Khalifa University in the United Arab Emirates, characterises the seismic hazard along the Suez-Ismailia-Cairo corridor as moderate but spatially variable. The area contains active or potentially reactivated faults, sedimentary basins and soil deposits capable of amplifying ground motion, while its densely populated cities and interconnected infrastructure mean that even a moderate earthquake could have significant consequences. In Sawires’s preliminary assessment, a magnitude-5.6 earthquake is broadly consistent with the event sizes considered in existing regional hazard models and does not, by itself, demonstrate that those models have failed. Recent probabilistic studies in Egypt have increasingly sought to incorporate variations in soil properties, earthquake sources and scientific uncertainty. One study of a new urban community in Minya Governorate found that estimated hazard levels varied across the development because of differences in near-surface materials, illustrating the limitations of applying a single seismic-design value across a broad geographical zone. Egypt’s revised seismic building code is intended to assign more representative hazard values to individual cities and villages, refining or replacing the use of one value across an extensive zone. Sawires argues that Cairo, Suez and Ismailia should not automatically receive identical design parameters because their distances from earthquake sources and their geological and soil conditions differ, with such localised assessments being particularly important for critical and high-occupancy facilities. Mehanny, who is also contributing to the code revision, notes that although Egypt’s structural codes are moving closer to international standards, their effectiveness ultimately depends on design review, construction quality, site inspection and enforcement. Abdel Raheem similarly argues that the greater challenge is not necessarily a lack of seismic provisions. Modern editions of the Egyptian code already incorporate many internationally accepted principles, including seismic loading requirements, ductile detailing and minimum separation distances between adjacent structures. The more difficult problem, particularly for existing buildings, is ensuring that those provisions are consistently applied while unauthorised alterations are controlled and older structures are assessed and upgraded where necessary. The problem is not unique to Egypt. Countries with modern seismic standards can continue to carry substantial risk because much of their building stock was constructed before current requirements were introduced or has subsequently been altered, deteriorated or inadequately maintained. What should be assessed first? The Suez Canal corridor contains one of Africa’s most consequential concentrations of infrastructure, including ports, tunnels, bridges, pipelines, petroleum facilities and interconnected power and water networks, making targeted assessment of critical assets a priority. Sawires recommends inspecting reportedly damaged buildings and essential facilities, analysing strong-motion and aftershock data, expanding seismic and geodetic monitoring and developing city-scale microzonation studies capable of identifying variations in expected shaking within individual urban areas. Rather than assessing every older building in detail, Mehanny proposes a tiered programme based initially on construction age, structural type, height, occupancy and location, followed by rapid visual screening and detailed assessment of structures exceeding predefined risk thresholds. Hospitals, schools, emergency facilities, major bridges, power plants and essential networks should receive priority because many must remain operational after an earthquake to support emergency response and prevent disruptions from spreading through interconnected services. Abdel Raheem likewise recommends rapid screening after an event but stresses that assessments should look beyond obvious structural cracks. Engineers should also examine non-structural damage, soft or weak ground floors, irregular configurations, unauthorised floor extensions and other changes that may have altered the original structural system. Buildings showing significant vulnerabilities can then be referred for detailed engineering assessment, particularly where aftershocks could impose further demands on already weakened components. These concerns extend beyond Egypt, as a recent probabilistic assessment of seismic risk across Africa similarly emphasises that losses depend on the interaction between seismic hazard, population, exposed assets and vulnerable construction. Salama argues that stronger cooperation among African monitoring networks would improve data sharing, scientific understanding and regional preparedness. Retrofitting instead of demolition Reducing seismic vulnerability does not require every older building to be demolished and replaced because an assessment of each structure’s condition and weaknesses may identify interventions capable of improving its performance. Depending on the building, retrofitting may involve strengthening columns and beams, adding shear walls or steel bracing, improving foundations or installing devices designed to dissipate part of the energy transmitted during an earthquake. A 2024 Egyptian modelling study found that aluminium shear links and eccentric steel braces could reduce storey displacement and interstorey drift while improving the expected performance of two existing administrative buildings, although the proposed intervention has yet to be validated through completed field implementation. Mehanny also stresses that earthquake-resistant design does not promise zero damage but instead seeks different performance objectives under different levels of shaking. During frequent or moderate events, damage should remain limited and repairable, whereas the principal objective during a rare and severe earthquake is to preserve sufficient strength and ductility to prevent collapse and protect lives, even if the building suffers substantial or irreparable damage. The Suez earthquake does not indicate that a larger event is approaching, but it provided a real-world test of seismic monitoring, construction standards and emergency response. Its central lesson is that infrequent earthquakes do not mean negligible risk when moderate shaking encounters vulnerable buildings, amplifying soils, tightly packed urban structures and critical infrastructure that has not been systematically assessed.The post Suez earthquake raises alarm over Egypt’s hidden seismic risks first appeared on Dailynewsegypt.
