Disaster planners set to benefit from research ship's seismic survey off New Zealand's East Coast

"Unprecedented" 3D imagery of Hikurangi subduction zone hopes to hold the key to secrets of "slow slip" quakes.

The US research vessel, the Marcus Langseth with a group of international scientists on board, has arrived back in the port of Napier after five weeks away mapping fault lines off the North Island's East Coast.

"It's not just a map it's even better than that, it helps us make a 3D image of the subduction system so we can see all the faults in their complexity," lead geophysicist Dr Harold Tobin told 1 NEWS.

Researchers have been setting off over 40 sound sources in the water attached to 24 kilometres of cables with pressure sensors attached called seismic streamers.

They record the echoes that bounce back off the ocean bed.

The data is recorded every 30 seconds every day for 30 days, creating a detailed map of layers beneath the sea floor.

"We can see the strong spots or the week spots on the fault or the places where it's got complex structure and places it's got simple structure and all that helps seismologist and geologist."

It's hoped the mapping will help better understand the phenomenon of "slow slip" earthquakes which occurring frequently in the Hikurangi subduction zone.

Dr Dan Barker from GNS Science who has been on the vessel the past five weeks says the shaking from "slow slip" earthquakes isn't felt.

"They are effectively releasing energy the same way a large earthquake would but the big difference is they are happening slowly, a timeline of weeks to months."

The 7.8 magnitude Kaikoura earthquake in 2017 is believed to have triggered a slow slip off event off the coast of Gisborne.

Dr Harold Tobin says the preliminary results have already turned up interesting findings.

"What we have found that really is new is the complexity of that subsurface geology, there are faults that are winding round in all sorts of different places in 3D configurations."

The research will be used globally as well as locally by our own disaster planners.

Lisa Pearse from Hawke's Bay Civil Defence says research like this is amazing for preparing for those future disasters.

"We are really keen to learn about the risk of living in the subduction zone and what it means for our communities."

However, the findings won't be known for a few years yet as the data now will go away to be analysed.

A US research ship spend five weeks carrying out scientific research. Source: 1 NEWS

Two women on a mission to educate Kiwis about the dangers of old life jackets

Travelling the length of the country in a Coastguard van two women are out to swap dangerous old life jackets for new ones.

Since before Christmas last year Coastguard Boating Education's Sue Tucker and Mary Miller have taken over 3000 unusable life jackets out of commission and swapped them for new ones.

"There are some ignorant people but I really think everyone can be educated," says Ms Miller.

Along their journey they have discovered some shocking excuses for life jackets, including jackets with no foam, holes and one that was 60 years old. 

"At the end of the day, everyone wants to see their mate or family member come home," says safety educator, Sue Tucker.

It's the season for boating which means, sadly, the season for boating accidents. Source: Seven Sharp



Police release name of 14-year-old swimmer missing off Christchurch beach

Police have released the name of a 14-year old boy who went missing while swimming off Scarborough Beach in Christchurch on Monday.

He was Jack Sutton of Linwood.

Police and LandSAR volunteers are continuing to search the beach and coastline in Sumner for Jack. 

Police said tonight Jack's family would like to express their thanks for the care and support given to them by the Sumner community and have asked for privacy at this difficult time.

The 14-year-old went missing off Sumner Beach yesterday about 3.20pm. Source: 1 NEWS