New Zealand's biggest tsunami siren network will soon get its twice-yearly testing check along hundreds of kilometres of Northland coastline.
The six-monthly tests for 205 sirens will take place on Sunday as summer's daylight saving begins.
The outdoor tsunami sirens will simultaneously sound along Northland's coast, in coastal communities from Te Hapua in the north to Mangawhai in the south and Ruawai in the
The sirens alerted thousands of Northlanders for real in March this year, in the face of a tsunami warning after an 8.1 earthquake in the Kermadec Islands, 1000 kilometres north of New Zealand. Thousands evacuated to higher ground in the region's biggest tsunami evacuation.
Northland's tsunami siren network's twice-yearly testing coincides with the start and finish of daylight saving.
Northland Civil Defence Emergency Management (CDEM) Group spokesperson Victoria Harwood said it was important to continue siren network testing so any faults could be identified and repaired.
This was still the case in the current Covid-19 Delta variant outbreak.
"The tsunami risk to Northland's coastline – and the rest of the country – remains as it always has been, and we need to be certain this alerting technology is ready to go if it's needed," Harwood said.
The sirens will sound twice - at 10am (for 10 minutes) and at 10.30am (for 30 seconds) on Sunday.
Volunteers around the region will be out alongside the sirens, monitoring for faults.
Indoor tsunami sirens will also be tested at the same times as the outdoor network.
Test alerts will also be sent to Red Cross Hazard app users. The app can be downloaded for free https://www.redcross.org.nz/what-we-do/in-new-zealand/disaster-management/hazard-app/
Harwood said people should be aware of the risk from tsunami generated on, or close to, Northland's coast. These local-source tsunami could arrive ahead of any official warning.
"Everyone who spends time on the coast needs to know the natural warning signs of tsunami – a strong earthquake that is hard to stand up in or one that lasts longer than a minute, or out-of-the ordinary sea behaviour such as a sudden rise or fall and/or unusual noise," Harwood said.
Northland's outdoor tsunami sirens are funded and owned by the region's three district councils (Far North, Whangārei and Kaipara) and operated in a partnership which also includes the region's two electricity networks, Northpower and Top Energy.
The network has been progressively developed since 2007.
The sound of Northland's outdoor and indoor tsunami sirens can be heard online at www.nrc.govt.nz/tsunamisirens