Ship availability after a megathrust earthquake and tsunami event: A case study on Canada’s West Coast

• Earthquake-tsunami events can damage ships and marine infrastructures. • A model to estimate the ships available to help the emergency response is presented. • The model is applied to a Cascadia scenario on Canada‘s West Coast. • Only 6 ships are expected to be free from damage. • The Strait of Juan de Fuca is considered a dangerous area for ship navigation. Disasters such as earthquakes, tsunamis, hurricanes, and storm surges can severely damage vessels, port infrastructure, and other maritime assets, which are vital for the emergency response of coastal communities and islands. One region particularly susceptible to megathrust earthquakes is near Vancouver Island, where the Cascadia Subduction Zone is located. In this context, this paper presents a model designed to estimate the number of vessels (including ferries and tug-barge combinations) available for emergency response, map out the most dangerous areas for navigation, and identify the routes expected to experience a reduced flow of supplies. The case study results indicate that smaller vessels, such as small ferries and certain tugs, are likely to be unavailable during emergencies, while larger ferries are expected to remain operational. The insights gained from the model are valuable for decision-makers, as they can improve their existing emergency response plans. Future studies could apply the model to other contexts, incorporate additional features, and enhance the overall evidence base.