Rising sea levels present one of the most pressing threats to coastal environments worldwide, but beyond environmental consequences, these changes pose acute risks to cultural heritage sites that have stood for centuries. A recent groundbreaking study led by researchers at the University of Hawai‘i at Mānoa sheds light on the imminent dangers faced by Rapa Nui’s iconic Ahu Tongariki, a ceremonial platform that hosts some of the world’s most famous moai statues. Using advanced computational simulation and digital twin modeling, the researchers were able to project that seasonal wave inundation could begin to regularly affect this UNESCO World Heritage site as early as 2080. This revelation signals an urgent call to action for communities, preservationists, and policymakers alike.
Ahu Tongariki, located on the southeastern coast of Rapa Nui (Easter Island), is not just a tourist attraction; it is a profound symbol of cultural identity and resilience for the island’s inhabitants. The moai statues, carved from volcanic stone between the 13th and 16th centuries, have weathered centuries of harsh oceanic winds and natural disasters. Yet, this study reveals that rising sea levels, combined with increased wave energy due to climate change, threaten to submerge these sacred sites intermittently in the coming decades. Such flooding would not only physically damage the structures but could also destabilize the cultural fabric and economic foundations reliant on heritage tourism.
The research team employed a sophisticated approach by creating a high-resolution digital twin of the Tongariki coastline. This digital twin—a precise computational replica—was integrated with hydrodynamic wave models that simulated how future sea level rise could amplify wave reach inland. By layering flood projections over detailed geospatial data pinpointing cultural assets, the investigators identified the areas most vulnerable to episodic inundation. This method represents a significant advancement in heritage site risk assessment because it accounts for complex interactions between oceanographic forces and topography at an unprecedented level of detail.
Lead author Noah Paoa, a doctoral candidate in the Department of Earth Sciences at UH Mānoa, explains that this simulation approach bridges a crucial gap in understanding how sea level rise translates into real-world impacts on culturally significant locations. “The critical question was not if these sites would be impacted, but when and how severely,” Paoa noted. By narrowing the risk timeline to mid-to-late 21st century, the study equips local stakeholders with actionable information to spur protective measures, adaptation strategies, and community dialogues centered on preserving Rapa Nui’s heritage.
Importantly, the study draws attention not only to the physical risks but also to the socio-economic consequences tied to heritage loss. The island’s identity is deeply connected to its ancestral sites, which continue to foster spiritual and cultural continuity for the Rapa Nui people. At the same time, tourism driven by the allure of the moai statues constitutes a vital economic pillar. Damage or loss of these assets could reverberate through the local economy, undermining livelihoods and community stability, underscoring the multifaceted stakes of climate change impacts on cultural heritage.
Co-author Chip Fletcher, dean of the School of Ocean and Earth Science and Technology (SOEST), emphasizes the broader implications for coastal communities worldwide. “Our imperative extends beyond engineering safe infrastructure,” he states. “We must also document and protect the cultural landscapes that define community identity. This study demonstrates how combining scientific innovation with community collaboration can help anticipate and mitigate risks to what matters most.” The approach used in Rapa Nui may serve as a replicable model for other heritage sites threatened by climate change, especially those located in island and coastal environments.
The convergence of digital technologies with environmental science showcased in this study is particularly compelling. The digital twin concept allows researchers to visualize dynamic environmental systems interacting with human heritage elements, enabling precise scenario planning. This represents a transformative shift from traditional hazard assessments, which often lacked spatial or temporal resolution adequate for cultural asset preservation. By advancing this modeling framework, the team sets a benchmark for future interdisciplinary research integrating computational simulation with cultural heritage conservation.
The findings carry a sobering message: the accelerating pace of sea level rise and intensifying wave action demand immediate attention from cultural preservation sectors. Global sea levels are projected to rise significantly by 2100 due to climate change, primarily from melting glaciers and thermal expansion of oceans. For localized regions like Rapa Nui, this translates into increased flooding events, coastal erosion, and saltwater intrusion. These factors, when combined with the island’s limited landmass and exposure, compound the vulnerability of its cultural sites. Without preemptive measures, the impact could soon transition from theoretical risk to tangible loss.
The research also highlights the value of partnerships between scientists and local communities. The cultural asset locations incorporated into the simulations came from indigenous knowledge and collaborative engagement with Rapa Nui partners. Such inclusivity ensures that scientific outputs remain grounded in community realities and respects the importance of traditional knowledge in heritage protection. This collaborative framework is essential to crafting culturally appropriate and broadly supported adaptation plans that honor the spiritual and historical significance of the sites.
Looking forward, the research team intends to expand their scope by investigating the impacts of sea level rise on other coastal cultural assets, both within Rapa Nui and across the Pacific. There are plans to assess the efficacy of various adaptation and mitigation strategies aimed at minimizing damage, including physical barriers, landscape modifications, and cultural resource management protocols. This iterative, iterative approach recognizes that addressing climate impacts on heritage is a dynamic process necessitating ongoing vigilance and recalibration as new data emerge.
Perhaps most critically, Paoa underscores the necessity of ensuring that future interventions be guided by the communities they affect. “The science provides a blueprint, but it is the voice and values of the Native Hawaiian community and the people of Rapa Nui that must shape how we proceed,” he said. This principle serves as a model for cultural preservation efforts globally, affirming that scientific inquiry must always be conducted in respectful partnership with Indigenous peoples to achieve sustainable and just outcomes.
In sum, the study not only reveals a tangible timeline for sea level rise impacts on Ahu Tongariki and its moai but also pioneers the integration of computational modeling with cultural heritage risk assessment. As climate change continues to reshape coastlines globally, innovations like these offer crucial tools to safeguard the legacies embedded in sacred sites. The world’s cultural treasures depend not only on environmental stewardship but on the fusion of technology, science, and community resolve to preserve our shared human history in the face of unprecedented change.
Subject of Research: Impacts of sea-level rise and wave inundation on cultural heritage sites, specifically Ahu Tongariki in Rapa Nui.
Article Title: Impacts of sea-level rise and wave inundation in the Tongariki Complex, Rapa Nui
News Publication Date: 22-Jul-2025
Web References:
- Journal of Cultural Heritage article: https://www.sciencedirect.com/science/article/pii/S1296207425001360?via%3Dihub
- DOI: http://dx.doi.org/10.1016/j.culher.2025.07.004
Image Credits: Noah Paoa
Keywords: Sea level rise, Coastal flooding, Rapa Nui, Moai statues, Ahu Tongariki, Cultural heritage, Digital twin, Computational simulation, Climate change impact, Coastal vulnerability, Ocean wave modeling, UNESCO World Heritage site
