The research, led by Rashid Haider of RWTH Aachen University and the Geological Survey of Pakistan, together with colleagues in Pakistan, China and Germany, focuses on four long-standing puzzles surrounding the 1945 tsunami at the Pasni coast. First, the waves arrived one to two hours later than a directly propagating tsunami from the known epicentral region should have. Second, the wave heights reached at least ten metres, an exceptional value given the magnitude of the parent earthquake. Third, survivors consistently reported three successive waves rather than a single surge. Fourth, the sea first withdrew from the shore, a temporary shoreline regression known as an initial draw-down, before the flooding began.

To resolve these puzzles, the team tested three near-field tsunamigenic earthquake scenarios, simulating the full chain of tsunami physics: generation at the seafloor, propagation across the Arabian Sea, coastal inundation, and the interaction of waves through reflection and amplification. The modelling, which drew on high-resolution topographic and bathymetric data, including an unprocessed digital elevation model provided by the German Aerospace Center, allowed the researchers to track how the tsunami energy behaved once it reached the shallow waters and rugged shoreline of the Makran margin.

The simulations point to a phenomenon the authors call reflection-amplification as the key mechanism behind both the extraordinary wave heights and the delayed arrivals. Two geomorphic reflectors dominate this process. The first is a set of coastal beach cliffs that extend intermittently along the shore, bouncing incoming wave energy back toward the sea. The second, and more consequential, is a bathymetric high, a structural shelf rim on the seafloor that runs continuously along the entire Makran coast of Pakistan. Together, these natural mirrors turned the shallow shelf into a kind of echo chamber for tsunami energy.

The quantitative results are striking. According to the study, a primary tsunami wave of approximately five metres in height can be amplified to roughly ten metres through reflection-amplification, effectively doubling the destructive potential of the original wave. Crucially, this amplification is not instantaneous. The reflected and re-reflected wave energy takes more than eighty minutes, about an hour and a half, to develop fully and strike the coast. That delay explains why the destructive waves at Pasni arrived one to two hours after the earthquake, long after residents might have assumed the danger had passed.

The mechanism also accounts for the three distinct waves reported by survivors. The researchers found that the wave package reaching the coast could be categorised into three major wave-sets, matching the accounts collected from tsunami survivors, including interviews documented by UNESCO. The first wave corresponds to the direct arrival, while the subsequent sets reflect energy that bounced between the shelf rim and the shoreline before returning, enlarged, to the coast. The initial draw-down, the eerie withdrawal of the sea, fits naturally into this sequence as the leading depression of the tsunami signal and the interaction of the wave train with the shallow shelf.

Perhaps the most consequential conclusion of the study is its verdict on the tsunami’s source. Previous researchers had proposed that a submarine landslide, or a combination of earthquake slip and landslide, might be needed to explain the outsized waves. By showing that reflection-amplification alone can transform a moderate primary wave into a ten-metre monster, the team argues that a single earthquake can account for all four observed features of the 1945 event. In their integrated and comparative analysis, no secondary landslide source is required, simplifying the picture of tsunami generation in one of the world’s least understood subduction zones.

The Makran subduction zone, where the Arabian plate slides beneath the Eurasian plate along the coasts of Iran and Pakistan, remains a region of considerable seismic uncertainty. Compared with better-studied margins such as Nankai in Japan or Sumatra in Indonesia, the Makran has produced few instrumentally recorded great earthquakes, and the 1945 event remains its only well-documented tsunamigenic rupture. The new findings suggest that hazard assessments for the region cannot rely on earthquake magnitude alone. Even a moderate megathrust rupture could produce devastating local waves if the coastal cliffs and the continuous shelf rim amplify the signal as they did in 1945.

The implications extend to the rapidly developing coastline of southern Pakistan, including the port city of Gwadar and the town of Pasni, where population and infrastructure have grown substantially since 1945. If a future earthquake produces a primary wave of only a few metres, the reflection-amplification mechanism identified in this study could still deliver waves of catastrophic height to nearby shores, and the hour-and-a-half development time means that the worst flooding may come well after the shaking has stopped. The authors emphasise that further investigation is needed, particularly in reassessing the 1945 earthquake in terms of its fault parameters and fault location, and in characterising the local tsunami reflection-amplification phenomenon in greater detail.

By reinterpreting one of the deadliest tsunamis of the twentieth century through the lens of wave reflection, the study offers both a solution to an old mystery and a warning for the future. The same cliffs and seafloor ridges that shaped the 1945 disaster are still in place along the Makran coast, ready to amplify the next tsunami. Understanding how they work, the researchers argue, is now essential for protecting the communities that live in their shadow.

Subject of Research: Reflection-amplification of the 1945 Makran tsunami by coastal cliffs and a bathymetric shelf rim along the Pakistan coast

Article Title: Tsunami amplification and time-delay mechanism; an insight into the case study of the 1945 tsunami event, Makran coast, Pakistan

Article References: Haider, R., Javed, H., Gardezi, S. A. H., Ali, S., Hoffmann, G., & Reicherter, K. (2026). Tsunami amplification and time-delay mechanism; an insight into the case study of the 1945 tsunami event, Makran coast, Pakistan. Natural Hazards, 122(19), Article 634. https://doi.org/10.1007/s11069-026-08398-x

Image Credits: AI Generated

DOI: 10.1007/s11069-026-08398-x

Keywords: 1945 Makran tsunami, Makran subduction zone, tsunami reflection and amplification, tsunami arrival delay, Pasni coast, Pakistan, numerical modelling, bathymetric high, initial draw-down, earthquake source, Natural Hazards, tsunami hazard

Recent advancements in three-dimensional thermal modeling have enabled researchers to gain unprecedented insights into the intricate thermal state and depth of the subducting slab in the Makran Subduction Zone. This innovative approach allows for a more nuanced analysis of how temperature variations affect slab dynamics and contribute to seismic events. By integrating these models with field data, scientists can elucidate the thermal conditions present at various depths beneath the surface, thus creating a comprehensive framework for understanding subduction-zone evolution.

The thermal conditions within the MSZ significantly influence the geological phenomena associated with subduction, such as slab metamorphism and fluid release. This interplay is crucial, as it affects both the physical properties of the subducting material and the broader tectonic context. As the slab descends into the mantle, variations in temperature and pressure lead to complex metamorphic reactions. The outcomes of these processes often determine the region’s seismicity, as fluids released from the slab can alter the frictional properties of the overlying rocks, potentially triggering earthquakes.

Investigating the seismic events recorded in the Makran region reflects the ongoing tectonic dance between the Arabian and Eurasian Plates. Data from seismic monitoring activities have pinpointed epicenters of earthquakes occurring within this influential tectonic boundary. The cluster of recorded seismic events over the past two decades illustrates not just the energy released from sudden slips along fault lines but also highlights the regions most prone to future seismic hazards. Understanding this earthquake distribution is vital for assessing risk and enhancing preparedness in this populated coastline.

The various features of the Makran Subduction Zone, such as the isodepth contours of the subducting plates that emerge clearly from modern tectonic maps, demonstrate the ongoing geological processes at work. These contours reflect the complexity of the geological structures involved, showcasing how the Arabian Plate dips beneath the Eurasian counterpart at varying depths, ranging between twenty to sixty kilometers. Such intricacies underscore the need for thorough research and robust modeling to predict potential seismic hazards and inform local communities accurately.

Moreover, the relationship between slab dehydration and the occurrence of earthquake events cannot be overstated. As the subducted slab undergoes metamorphic changes, volatiles such as water and carbon dioxide are expelled back into the overlying mantle. This process not only influences the physical properties of the surrounding rocks but also has explosive geological implications. The pressure from fluids can result in increased instability along fault lines, making it a critical factor in the study of seismic activity. Understanding this relationship is paramount for the scientific community striving to predict and mitigate seismic risks.

The research surrounding the Makran Subduction Zone is not merely academic; it carries direct implications for the numerous communities residing along its fault lines. With the threat of major seismic events looming, there exists an urgent need for appropriate hazard assessment and disaster readiness. The insights gleaned from 3-D thermal modeling and seismic data can inform both policy makers and the general public regarding the risks posed by living in a seismically active area, thereby promoting safety measures, improved building standards, and community awareness programs.

The future of research in the Makran Subduction Zone seems promising, with improving technologies paving the way for more refined models and analyses. As scientists continue to deepen their understanding of how subduction processes unfold, they will not only unpack the mysteries of this particular zone but also contribute to the broader knowledge of tectonic behavior globally. The critical assessment of these processes can enhance predictive capabilities, ultimately leading to better-prepared communities worldwide.

Furthermore, elucidating the interplay of tectonic plates in the MSZ provides a vital context for understanding similar subduction zones across the globe. Lessons learned from the Arabian-Eurasian interaction could be extrapolated to other regions, enhancing our cumulative knowledge of tectonics and potentially improving seismic hazard mitigation efforts internationally. This has far-reaching implications for global geological research and the safety of communities residing in seismic hot spots.

The significance of the Makran Subduction Zone goes beyond local geology and tectonics; it is a vital component of the Earth’s dynamic behavior. By exploring the mechanisms that drive the subduction processes here, researchers broadly contribute to the understanding of planetary formation and evolution. New perspectives on the behavior of the subducting slabs inform global models of tectonic activity, enhancing our comprehension of the complex dance between Earth’s plates and the forces that shape our world.

In conclusion, the ongoing exploration and research pertaining to the Makran Subduction Zone harness both basic scientific inquiry and practical applications, making it a vital area of study. By understanding the key factors that govern its seismic activity, scientists are not only shedding light on geological processes but also making strides toward securing the safety of millions who live under the specter of these tectonic giants. It is the collaboration of cutting-edge research and community awareness that will ultimately lead to informed preparedness in the face of natural disasters, enhancing resilience in vulnerable regions.

Subject of Research: Thermal modeling and seismic activity in the Makran Subduction Zone
Article Title: Subduction thermal state, slab metamorphism, and seismicity in the Makran Subduction Zone
News Publication Date: 4-Mar-2025
Web References: DOI
References: Smith and Sandwell (1997), Hayes et al. (2018), Trabant et al. (2012), Siebert et al. (2011)
Image Credits: Beijing Zhongke Journal Publishing Co. Ltd.

Keywords

Subduction, seismicity, Makran, thermal modeling, earthquake risk, tectonics, slab metamorphism, geological processes, Arabian Plate, Eurasian Plate.