The Sumatra Tsunami of Boxing Day 2004 propagated around the entire globe, as indicated in this figure showing the maximum wave height from computer modelling done by the NOAA/PMEL team. The propagation path of the tsunami from its origin to New Zealand is extremely tortuous: the continent of Australia is directly in its path, but more importantly the seafloor is highly variable, with many trenches and shoals between Sumatra and New Zealand. Tsunami waves feel every fluctuation of the seafloor and respond to them. Therefore, it is no surprise that the response of the ocean around New Zealand was highly variable. And as the waves propagated into harbours, they modified further in response to the shape of the harbour and its bed.
The purpose of this webpage is to present a summary of the tsunami waves that were measured in the various ports and harbours around New Zealand. An important point that arises from viewing these plots is that each port or harbour responded differently. Therefore, each port needs to assess the risk of their port to tsunami attack. There is no overall formula that can be applied to all ports.
In the table below, we present a summary of the tsunami waves at each port. Detecting the time of arrival (TOA) of the first waves was not easy for some sites because there were long waves present already, and the first tsunami waves were very small. This was true for all ports. The same happened in the Peru Tsunami of 2001. The first waves were very small and they built up over a day or more. This is interesting because it differs from the image many researchers have of a tsunami being a train of solitary waves led by the largest. Indeed, the tsunami waves recorded at NZ ports look very similar to meteorologically-generated long waves, only with periods several times longer.
|Harbour||First Waves||Highest Wave|
|TOA h||Height mm||Period min||TOA h|
TOA=Time of Arrival in hours after the earthquake.
To retrieve details of the tsunami waves in a particular harbour, click on the name in the map below:
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