Tauranga City Council is issuing a warning for people to be better prepared for a large earthquake and a potential tsunami evacuation.

CEO Garry Poole held briefings with around 300 city council staff on Tuesday discussing information from GNS, suggesting there may be an increased likelihood of a large-scale earthquake affecting the east coast of the North Island.

Slow-slip seismic events occurring simultaneously in the Gisborne, Hawke's Bay, and now Kapiti regions, have been observed by GNS, which they suggest may mean there is an increased risk of a large earthquake (M7.8 or greater) in the lower North Island.

If it happens, it would likely cause a large tsunami that would pose a threat to coastal communities in much of the North Island, the Upper South Island, and Chatham Islands.

GNS :What do these slow-slip events mean for future earthquakes?

The increased likelihood is not a prediction, but it raises questions about community readiness should such an event occur, says Garry.

'We know that our community needs to be better prepared. This is part of living in New Zealand. For our part at Tauranga City Council, we are trying to practice what we preach by ensuring that we, as Council staff and members of the community, each have emergency plans in place for our own personal and family safety.

'Many of us have official roles to play in an emergency. We will not be able to perform those roles effectively if we are worried about the safety of our families.”

Staff at the briefings were given Get Ready Get Thru emergency checklists and encouraged to make use of websites like getthru.govt.nz and happens.nz to work through questions such as: Is there anything in my home that needs to be secured in case of an earthquake? Where do my loved ones spend their day and what is the plan for my children if I can't get to them? Tsunami evacuation is a very real concern for everyone.

'Many of our staff live or spend time along the coast and we all have friends, colleagues and families who need to know when, where and how to evacuate to survive a tsunami,” says Garry.

An earthquake is the first warning sign for a tsunami, says emergency management manager Paul Baunton.

'If the shaking lasts longer than a minute or if it is strong enough to knock you over, that is the number one warning sign to evacuate immediately.

"We have excellent maps for Tauranga that you should use to plan and practice your evacuation route. The maps are based on a 14m tsunami, which is very much a worst case event for our region. Even for the worst case scenario, the maps show that there are safe areas right along the coast that you can get to on foot. It is especially important that you evacuate by foot or bicycle to avoid crippling traffic jams.”

People should also make plans with their neighbours and help to alert them during an evacuation. 'We're all in this together as a community.”

Tauranga City evacuation maps are online at www.tauranga.govt.nz/tsunami

Updated versions will be published within the next week.

Sign up for alerts:

• Text ‘TA' or ‘WB' to 2028 to receive text alerts for Tauranga or Western Bay
• bopcivildefence.govt.nz
• Download the free Red Cross Hazard App

Information sites

• www.getthru.govt.nz
• www.happens.nz
• www.bopcivildefence.govt.nz
• GNS information about slow slip events