This study presents the results of an experimental research program dealing with spatial debris motion on a horizontal apron depicting a typical harbor wharf. Accordingly, scaled-down 6.1-m (20-ft) shipping containers were equipped with a novel yet nonintrusive real-time tracking system and motion sensors. The instrumentation allowed for the spatiotemporal tracking of debris specimens moving across the apron while entrained by an incoming tsunami-like broken bore. The system proved its capabilities and accuracy; this was particularly challenging since this was the first time the system was used in water. The experiments involved using various numbers of shipping containers that were either arranged in one layer or stacked in two layers. In addition, the effect of different numbers of container rows was also investigated to study the influence of the overall container count and placement with respect to their longitudinal displacement and dispersion (spreading) across the apron. Linear relationshi...

Recent extreme hydrodynamic events, such as the 2004 Indian Ocean Tsunami, 2005 Hurricane Katrina, and 2013 Typhoon Haiyan, have indicated the vulnerability of coastal communities. As a result, emphasis has been placed on understanding and developing methods of assessing the potential loads associated with these extreme events. The majority of research has focused on assessing the risk of hydrodynamic loads; however, little research has gone into assessing the potential for debris loading. The following study aimed to address the trajectory of debris within extreme hydrodynamic conditions to aid in the assessment of risk for debris loading. Laboratory experiments were performed using a dam-break wave as the hydrodynamic forcing condition. The trajectory and velocity of the debris were examined to determine the statistical characteristics of the debris motion. The study showed that the lateral displacement of the debris can be evaluated using a normal distribution, and the velocity of the debris can be conservatively modeled as the wave front velocity.

The September 28 2018 Palu tsunami surprised the scientific community, as neither the earthquake magnitude nor its strike-slip mechanism were deemed capable of producing the wave heights that were observed. However, recent research has shown that the earthquake generated several landslides inside Palu bay. The authors conducted a post-disaster field survey of the area affected to collect spatial data on tsunami inundation heights, nearshore and bay bathymetry, and carried out eyewitness interviews to collect testimonies of the event. In addition, numerical simulations of the tsunami generation and propagation mechanisms were carried out and validated with the inferred time series. Seven small submarine landslides were identified along the western shore of the bay, and one large one was reported on the eastern shore of Palu City. Most of these landslides occurred at river mouths and reclamation areas, where soft submarine sediments had accumulated. The numerical simulations support a scenario in which the tsunami waves that arrived at Palu city 4–10 min after the earthquake were caused by the co-seismic seafloor deformation, possibly coupled with secondary waves generated from several submarine landslides. These findings suggest that more comprehensive methodologies and tools need to be used when assessing probabilistic tsunami hazards in narrow bays.