Forecasting the impact of storm waves and sea-level rise on Midway Atoll and Laysan Island within the Papahānaumokuākea Marine National Monument—a comparison of passive versus dynamic inundation models

Classic atolls with islands on shallow rims are more vulnerable to the combined effects of sea-level rise and storm waves, leading to earlier and more severe inundation than predicted by passive models. This study compared dynamic inundation models—accounting for wave-induced set-up and run-up—to passive 'bathtub' models using Midway Atoll (shallow rim) and Laysan Island (deep rim). Findings revealed that sea-level rise increases wave heights and wavelengths, amplifying run-up despite reduced set-up. Dynamic modeling showed substantial inundation at lower sea-level rise thresholds than passive models, suggesting infrastructure and ecosystems on shallow-rim atolls face heightened risks sooner in the 21st century.

Storlazzi, C. D., Berkowitz, P., Reynolds, M. H., & Logan, J. B. (2013). Forecasting the impact of storm waves and sea-level rise on Midway Atoll and Laysan Island within the Papahānaumokuākea Marine National Monument—a comparison of passive versus dynamic inundation models. Open-File Report. https://doi.org/10.3133/ofr20131069