Tuesday, December 10, 2024

Winds of change for Auckland tsunami evacuation maps

Auckland Council says new modelling shows the area of Tāmaki Makaurau at risk from damaging tsunami waves is less than previously expected.

Auckland Emergency Management has updated and simplified the region’s tsunami evacuation maps to reflect this change and make them easier to understand.

Auckland Emergency Management’s Head of Operations, John Cranfield is encouraging Aucklanders to view the updated evacuation maps through Auckland’s Hazard Viewer to see if they live, work or play in a tsunami evacuation zone.

“Our new tsunami wave modelling is more accurate and indicates the tsunami risk for much of the Auckland coastline to be lower than previously expected,” he said.

“Aucklanders should check out the Hazard Viewer to help them become familiar with areas predicted to be flooded during a tsunami, as part of being prepared for an emergency.”

The new mapping uses modelled earthquakes on real fault lines around the Pacific to replicate how tsunami waves are generated and track across the ocean and to the coastline.

The modelling takes into account how islands influence the path of tsunami waves, as well as how landforms on the coast and the shape of the seafloor influence the way tsunami waves behave.

Mr Cranfield says the new maps are also simpler to understand.

“The new maps use a two-colour system. The red zone shows the area needing to be evacuated in a shore and marine tsunami threat, when strong and unusual currents and dangerous surges at the shore are expected.”

“The yellow zone shows the area needing to be evacuated where there is a land tsunami threat, where tsunami flooding is expected to affect inland areas.”

The new maps cover the entire Auckland coastline including the Hauraki Gulf Islands and Aotea Great Barrier Island.

Auckland Council’s Civil Defence and Emergency Management Committee chairperson, Councillor, Sharon Stewart says it’s pleasing that new evacuation maps show fewer areas at-risk from tsunami flooding but that Aucklanders should still be alert to the risk of tsunami threats.

“The new modelling suggests fewer of our coastal communities are expected to be impacted during damaging tsunami in Tāmaki Makaurau,” she said.

“Particularly the areas surrounding the inner Manukau, Kaipara and Waitematā harbours and on the west coast beaches, where impacts are now expected to be confined to shore and marine areas.

“However, areas more exposed to the Pacific Ocean like Aotea Great Barrier Island and Auckland’s north-eastern coastal communities are still at risk of large tsunami, as is anyone that enjoys the beaches and marine areas of the region. People need to remain prepared to move quickly in a tsunami emergency.”

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