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Protecting coastal infrastructure requires a thorough understanding of coastal processes and wave propagation from deep water. The southeast Queensland coast is exposed to a highly dynamic variety of wave sources including high-energy tropical cyclones, persistent trade winds, east coast lows and Southern Ocean storms. Strong effects of currents on wave propagation often occur near tidal entrances, however the impact of strong currents on wave propagation offshore is rarely considered. The effect of the East Australian Current (EAC) and its variability on deep-water wave propagation to the coast is the focus of this study. We explore wave-current interaction by process-based modelling of the EAC and its influence on wave propagation to coastal waters. Data from a suite of deep water and nearshore monitoring buoys in Southeast Queensland were analysed to study the wave transformation under the influence of the EAC. These data were compared to the Centre for Australian Weather and Climate Research (CAWCR) hindcast wave model data and used for calibration of a local numerical model employed in this study. The results indicate that the wave hindcast model tends to underestimate significant wave height during highenergy events. To address this limitation, an artificial neural network (ANN) model is employed, incorporating output from a hindcast-driven numerical model. The ANN model successfully improves the wave hindcast data used as wave boundaries, thereby enhancing the performance of the local numerical model in accurately representing deep and nearshore wave data. We conducted tests with the coupled wave and hydrodynamic models to compare wave propagation under various scenarios, including tidal forcing, boundary current input from regional models, and local and regional wind conditions. These results demonstrate the variability of the EAC, but also reveal an underestimation of the current compared to observed data. A better understanding of the coupled wave-current interaction can assist future coastal management strategies. [ABSTRACT FROM AUTHOR]

The explosive eruption of the Hunga-Tonga Hunga-Ha'apia volcano transmitted a pressure wave radially from the explosion site, which was reported by pressure sensors across Australia and the globe. Based on modelled traditional seismic tsunami travel speeds, a tsunami was forecast to arrive at the eastern Australia coast within five hours of the eruption. The pressure wave took three hours to reach the east coast of Australia, while the tsunami arrived only 33 minutes after the atmospheric pressure wave. An increase in tsunami amplitude coincides with the modelled arrival time suggesting a two-phase nature of the tsunami. The tsunami resonated over the continental shelf with a peak wave period of 85 to 93 minutes at sites on the central east coast. The peak wave period at an offshore site that has no continental shelf (Norfolk Island) shows a tsunami peak wave period of around 5 minutes. Sea surface perturbations from two tsunami are represented by short period tsunami at an offshore island site, while at coastal east Australia sites, local resonance transferred tsunami energy into longer periods and excited a dominant fundamental oscillation mode through continental shelf resonance. [ABSTRACT FROM AUTHOR]