Assessment of the tsunami-induced current hazard

Abstract

The occurrence of tsunami damage is not limited to events causing coastal inundation. Even without flooding, maritime assets are vulnerable to significant damage from strong currents and associated drag forces. While such impacts have been observed in the past, they have not been well studied in any context. Nearshore tsunami currents are governed by nonlinear and turbulent physics and often have large spatial and temporal variability making high-fidelity modeling particularly challenging. Furthermore, measured data for the validation of numerical simulations is limited, with few quality data sets appearing after recent tsunami events. In this paper, we present a systematic approach for the interpretation of measured tsunami-induced current impacts as well as a validation approach for simulation tools. The methods and results provided here lay the foundation for much needed efforts to assess tsunami hazards in ports and harbors.

Assessment of tsunami hazards in ports and their impact on marine vessels derived from tsunami models and the observed damage data

“…Lynett et al (2014) developed a damage index of ports and their facilities based on the numerically predicted or instrumentally recorded data of tsunamis current in California. Previously, Suppasri et al (2013a) and Muhari et al (2013) introduced loss functions to indicate the damage probability of marine vessels subjected to tsunami hazards.…”

Tsunami currents in ports

“…As mentioned above, recent studies in California [44] established methodologies for assessing tsunami current hazards in ports. In New Zealand, Borrero et al [45] systematically extended this analysis to four major ports using the database-driven approach described above.…”

“…The results, as shown in figure 7, suggest that tsunami currents are more sensitive to source location than are tsunami heights. These sorts of assessments can be used to identify locations in ports that are particularly susceptible to strong currents as in Lynett et al [44]. Results from this modelling effort have been integrated into tools for use by emergency managers in New Zealand to provide port-specific warning guidance and information.…”

“…Lynett et al [44] summarize recent harbour hazard mapping efforts in California. In this paper, a simple correlation was found between hindcasted (modelled) currents and observed damage.…”

“…This current-damage connection allows for the generation of damage potential maps, which can be used for both during-event positioning of vessels as well as longterm planning of harbour infrastructure. Indeed, the work of Lynett et al [44] is leading to the development of US national guidelines for maritime tsunami hazard assessment and products by the National Tsunami Hazard Mitigation Program. Outside of the USA, this approach was used by Borrero et al [45] to assess the tsunami hazard at ports in New Zealand.…”