Waikato Regional Council have produced tsunami assessments and maps for the following places in the Coromandel: Whitianga, Mercury Bay, Cooks Beach, Hahei, Hot Water Beach, Matarangi, Whangapoua, Kennedy Bay, Kuaotunu, Opito Bay, Whiritoa, Pauanui, Tairua and Whangamata.
These can be viewed through this link: https://www.waikatoregion.govt.nz/services/regional-services/regional-hazards-and-emergency-management/coastal-hazards/tsunami/eastern-coromandel-tsunami-strategy/
More than a dozen slow slip events (also known as "silent" earthquakes) have been recorded in New Zealand between 2002 and 2012. Scientists have only been able to detect them recently due to the advent of global positioning system (GPS) equipment which can detect sub-centimetre changes in land movements. As part of the GeoNet(external link) project in New Zealand, continuously operating GPS have been installed throughout the country. The GeoNet (external link)cGPS data show that these silent earthquakes occurring deep under New Zealand are changing the shape of parts of the North Island over time periods of weeks to years.
To read more about what slow slip earthquakes are, read the following articles:
A magnitude 7.5 earthquake occurred at 12.02am on the 14th of November. It was 15km deep with the epicentre being 15km north-east of Culverden. Two separate earthquakes occurred at the same time, causing a combination of strike slip faulting (side-by-side motion) and thrust faulting (where one side of the fault is uplifted).
The earthquake was widely felt and had a long duration. Initially a tsunami warning was in place for all of New Zealand's coastal areas but was scaled back, however, Kaikoura experienced 2.5 metres of tidal displacement.
Seabed uplift occured north of Kaikoura and some houses were displaced 10's of metres.
Raglan's water supply has been comprised due to the earthquake causing discolouration of the Riki Springs. Currently there is a boil notice and residents are urged to conserve water by only using it for essential needs such as drinking water until the supply is up to standard levels.
For infomation read the following article:
A tsunami warning was issued for the East Coast of the Coromandel causing residents to evacuate to higher ground, which was later cancelled.
The felt reports for the Waikato Region consisted of mainly weak to strong intensities. Many people woke to buildings creeking and swaying with no major building damage.
For more information on the earthquake, check out the following links:
Exercise Tangaroa(external link) was a national (Tier 4) interagency exercise which tested New Zealand's arrangements for preparing for, responding to & recovering from a national tsunami impact. It was based on a tsunami initiated by an earthquake in the Kermadecs.
To read more about the exercise, see the following article:
A 7.1 Magnitude quake struck 10km north-east of Te Araroa at a depth of 22km at 4.37am. A small 30cm tsunami was generated and hit the East Cape. There was a tsunami threat/warning issued by Civil Defence for the east coast of the upper North Island, which was later cancelled.
Tsunami preparation and risk has been an evident theme in the media - follow Civil Defence's message below in the case of an earthquake.
To understand New Zealand's tsunami risk, watch the video below by GNS Science:
White Island is a tourist hotspot in the Bay of Plenty Region, attracting over 10,000 visitors per year. Its barren landscape with geothermal areas, mud pools, continuous smoking and an abandoned sulphur mining factory make you feel like you are on another planet.
It is New Zealand’s most well-known active marine volcano located approximately 50 kilometres off the coast of Whakatane. In past eruptions it has produced both lava flows and ash deposits. The last eruption occurred on April 27th this year and could have potentially caused death if anyone was on the island.
A 2.4 tonne shipping container has been transported to the island and is located at the old mining site, used as a protection structure and a storage facility for food and supplies.
Check out the link below to see the reasoning behind this initiative and what was involved with getting it to the island.
To see the volcanic activity of both White Island and Mount Ruapehu, see GeoNet’s monitoring page:
The coastal erosion at Sunset Beach has become problematic, resulting in the surf lifesaving’s club tower having to be relocated twice in one year. The bottom carpark has experienced severe erosion and has now completely disappeared. The Port Waikato community is strongly involved with managing the erosion with the Waikato District Council and both have decided that managed retreat is the best long-term option for management.
To read more about this see the articles below:
The Kerepehi fault extends for approximately 80 kilometres from Tirau to the Hauraki Gulf, running through the Hauraki Plains. New research has found that the fault is more complex than previously thought, involving a belt of many faults.
The fault could potentially produce an event with a magnitude between 6.3 and 7.0. However, scientists don’t know exactly when this will be. It is expected to occur in the next thousand years.
The loosely connected faults could also join together, forming a larger fault rupture and could potentially trigger a tsunami in the area.
For more detailed information about the new research on the Kerepehi Fault, see the links below:
Contact the flood hazard information team:
Please note that we may be able to provide a faster response if you provide your phone number in your message. Flood hazard information reports will normally take between 1-5 working days to process depending upon the complexity of the request. Once the enquiry has been processed you will receive a PDF of the report via email from the Regional Hazards Office.
You will need to provide us with the following information so that we can process your enquiry efficiently:
An online coastal inundation tool has been developed by Rick Liefting, the Senior Regional Hazards Advisor at Waikato Regional Council, and is now available to the public. To access it click here.(external link)
It will allow people to see the impacts of projected sea level rise on coastal areas in the Waikato Region, focusing on Coromandel and Hauraki on the east coast and Mokau, Marokopa and Awakino on the West coast.
Projected sea level rise of 30 centimetres by 2050 and one metre by 2100 will increase risk in coastal areas and exacerbate the risk in areas already experiencing problems such as Cooks Beach.
Coastal erosion can intensify when storms combine with spring tides. This process is more common on coastlines that are low lying, making them more prone to flooding.
The tool does not give predictions on when specific sea level rises would be reached
To see the full article click here(external link).
NIWA's seasonal climate outlook gives an indication of expected air temperatures and rainfall for different regions of New Zealand.
To see the full outlook click here.(external link)
Keep an eye on the river levels in your area by taking a look at the WRC river level and flow(external link) map.
New Zealand has a lot of active volcanoes and a high frequency of eruptions. There are three major types of volcano(external link) in New Zealand.Volcanic activity in New Zealand and occurs in six areas - five in the North Island and one offshore in the Kermadec Islands.
Volcano monitoring in New Zealand is undertaken by GNS Science’s GeoNet Project. Any future eruptive activity has to be watched out for, so that the sizes and styles of any eruptions, and their consequent threats to lives and property, can be forecasted.
Click here to see the Volcanic Alert Level Table(external link) on the GeoNet website.
The recently updated Volcanic Alert System table can be found here.
For more information on these alerts and New Zealand's volcanoes, see the volcanoes page(external link) on the GNS website.
Protecting New Zealand from Natural Hazards : An insurance Council of New Zealand perspective on ensuring New Zealand is better protected from natural hazards