Tsunami modelling

What are tsunami?

Tsunami are long period waves, most often generated by displacement of the sea floor associated with earthquakes, volcanic eruptions or landslides.

Tsunami can cause devastation to coastal communities with potential for destruction of coastal infrastructure, property and loss of life from the powerful waves and their inundation of land.

Damaged buildings from tsunami in 1916.Damage from tsunami of unknown source to Berghan Family Store at Ahipara circa 1916 (Image: Far North Regional Museum).

What can I do to help prepare?

Consult with your local authorities and civil defence representatives to understand and better prepare for tsunami hazard - and get involved with your local community emergency response planning.

Find out about Community Response Plans and if your community has one

Commissioned reports

The NIWA tsunami modelling relates to specific coastal settlements in Northland. Look up your settlement of interest in the table below to find which report you need to refer to:

Modelling Study 1 Modelling Study 2 Modelling Study 3 Modelling Study 4
4.4 Ahipara 4.2 Ruakaka 4.2 Whangaruru 4.3 Marsden Bay
4.5 Taipa 4.3 Paihia 4.3 Opua 4.4 Takahiwai
  4.4 Marsden Point (also see Study 4) 4.4 Mangonui 4.5 Oakleigh
  4.5 Russell 4.5 Houhora / Pukenui 4.6 Otaika
  4.6 Mangawhai 4.6 Helena Bay 4.7 Whangārei
  4.7 Tutukaka 4.7 Tauranga Bay 4.8 Bream Head
  4.8 Ngunguru 4.8 Taupo Bay  
  4.9 Tokerau 4.9 Coopers Bay  
  4.10 Waitangi 4.10 Langs Beach  
  4.11 Matauri Bay 4.11 Te Ngaire  
  4.12 Waipu Cove 4.12 Cable Bay  
  4.13 Pataua 4.13 Rangiputa  
  4.14 Matapouri 4.14 Hihi  
  4.15 Whananaki 4.15 Ruawai / Dargaville  
    4.16 Omapere  

The reports below, can be downloaded from the research and reports section of our website:

Tsunami source study

The aim of the project was to identify the most significant tsunami sources for the Northland, Auckland, Waikato and Bay of Plenty regions.

Northland Tsunami Baseline Study

A NIWA report on the pre and post-human tsunami record for the Northland Region.

Modelling Study 1

Modelling Study 1 gave a broad outline of the methodology, and included tsunami mapping for Ahipara and Taipa, in the Far North District.

Modelling Studies 2 and 3

Modelling Studies 2 and 3 include tsunami mapping for a further 30 settlements, primarily on the East coast of Northland, where tsunami risk is considered highest. 

Modelling Study 4

Modelling Study 4 included tsunami mapping for the Whangārei harbour, from the Whangārei Heads to the CBD. Six areas on the harbour have been studied in detail.

The methodology and scenarios assessed is consistent for model studies 1 to 4. For several tsunami event scenarios, the model outputs include:

  • landward extent and water depth of tsunami inundation over land
  • maximum current speeds from inundation over land
  • wave arrival times
  • animations of inundation for some areas.

Geophysical setting of the North Island showing two bathymetric wave guides to the northwest.Geophysical setting of the North Island showing two bathymetric wave guides to the northwest (the Chatham Rise acts as a wave guide to tsunamis approaching from across the eastern Pacific Ocean). See more in the Tsunami Sources Study.

Other useful resources