Early scientific work dating back to 2002 identified that the east coast of the Coromandel Peninsula is at risk from tsunami hazards. The emphasis on tsunami hazards increased following the South-east Asian tsunami in 2004, and this resulted in development of the first scientific modelling study of Whitianga and Mercury Bay in 2008. The 2008 study provided new information about the risk of large tsunami hitting Whitianga as a result of a major earthquake in the Tonga-Kermadec trench to the north-east of New Zealand. The devastating earthquake which struck Japan in 2011 was another graphic example of the threat posed by tsunami generated just offshore.
Eastern Coromandel Tsunami Strategy
In order to address the risk of tsunami along the eastern coast of the Coromandel Peninsula, Thames-Coromandel District Council, Hauraki District Council and Waikato Regional Council developed the ‘Eastern Coromandel Tsunami Strategy’. The purpose of the strategy is to identify tsunami hazards and minimise risks by informing and working with communities along the east coast of the Coromandel Peninsula.
Initial work undertaken in 2010/11 for Whitianga and Mercury Bay was followed up in 2013/14 with work in the Tairua and Pauanui communities, Whangamata and Whiritoa in 2014/15, Matarangi and Whangapoua in 2015/16, Kuaotunu, Opito Bay, Kennedy Bay and Mercury Bay in 2017/18, and Cooks Beach in 2018/19.
The work undertaken from 2008 onwards assessed the risk of tsunami affecting the eastern Coromandel Peninsula from both distant and near sources (see the overview of each of the coastal areas below). After each assessment, public open days or information sessions were held for each community. The open days provided a good opportunity for people to learn about tsunami hazards and risks on the Coromandel Peninsula, and an opportunity to provide input on how risks should be managed.
Firth of Thames/Coromandel Peninsula west coast
An assessment of the tsunami hazards along the west coast of the Coromandel Peninsula and in the Firth of Thames began in 2017/18. The assessment covers the communities of Colville, Coromandel, Manaia, Te Mata and Tapu, Waiomu, Te Puru and Thornton Bay, Thames and Kopu, Miranda, Kaiaua and Whakatiwai.
Information sessions will provide opportunities for community awareness and input during 2019/20.
Evacuation maps and procedures
The tsunami assessments have been used to assist communities in understanding what to do when there is a tsunami threat. To know more about evacuation procedures due to a tsunami threat, please click here(external link).
The first scientific modelling study of Whitianga and Mercury Bay was completed in 2008. The results of the study were discussed with the Whitianga community at two ‘open days’ in June 2011, the first to be held on the Coromandel Peninsula.
Significant changes to scientific modelling took place following the 2011 Japan tsunami, and this improved understanding led to improved modelling across the Coromandel Peninsula from 2012 onwards.
A report on the effects of the 1960 Chile tsunami(external link) undertaken in 2014 uncovered new information about the impact of distant tsunami on Whitianga, and provided verification of the scientific modelling. A reassessment of Whitianga and Mercury Bay tsunami hazard modelling was completed in 2017. In addition to Whitianga township, the 2017 assessment includes Wharekaho (Simpsons) Beach, Flaxmill Bay, Cooks Beach, Hahei and Hot Water Beach.
The 2017 assessment draws upon improvements in modelling since 2012, the 1960 Chilean tsunami report for Whitianga completed in 2014, and brings the modelling into line with other areas across the Coromandel Peninsula.
(note that Whitianga is the only significant area along the eastern Coromandel that is susceptible to tsunami inundation from a Distant Source event)
The previous information is available by request here.
Cooks Beach, Hahei and Hot Water Beach communities were included as a part of the 2017 Whitianga and Mercury Bay modelling assessment. An open day was held in Cooks Beach in November 2018 to share the results of the modelling with the community.
Scientific modelling of tsunami inundation along the Kennedy Bay to Opito Bay coast was completed in 2015. Open days were held in Matarangi and Whangapoua in January 2016, in Kennedy Bay in June 2016, and in Kuaotunu and Opito Bay in October 2016.
Scientific modelling of tsunami inundation in Whangamata and Onemana was completed in 2015. An open day was held in Whangamata in January 2015 to share the results with the community.
These posters and the following maps were on display at the tsunami open day in January 2015:
Scientific modelling of tsunami inundation in Whiritoa was completed in 2015 as a part of the Whangamata and Onemana assessment. The results of the assessment were presented in January 2015 at the annual community meeting.
These posters and following maps were on display at the tsunami open day in January 2015:
Scientific modelling of tsunami inundation in Pauanui and Tairua was completed in 2012. Open days were held in Pauanui and Tairua in January 2014 to share the results with the community.
Read Waikato Regional Council's technical report - Numerical modelling of tsunami effects at two sites on the Coromandel.