Scientists will soon start to dig trenches across some of the lines to see if they are active.<\/p>\n
So far the discovery has not increased the known risk to the city.<\/p>\n
One of the scientists, Auckland University senior lecturer James Muirhead, said any fault that had moved in the past 125,000 years was considered active.<\/p>\n
Some of the faults could have been still for six million years – which meant they were technically not active. Others were suspected faults.<\/p>\n
Muirhead’s team would begin by looking at some of the most likely – near Pukekohe or Drury in the city’s rural south.<\/p>\n
Diggers would carve out four-metre deep trenches across the fault which would then be analysed to see how recently they had moved.<\/p>\n
![\"Likely](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2026\/03\/likely-faults-possible-faults-and-possible-structures-identi-SKUSHPZCING5BA5FVWQOIZHRUU.jpg\")
<\/p>\n
Likely faults, possible faults and possible structures identified in the study superimposed on a shaded relief map of Auckland and plotted alongside Auckland Volcanic Field centres and earthquake epicentres since 1988. Photo: Supplied (Source: rnz.co.nz)<\/p>\n
“So hopefully two years from now we have a really good answer to that question – whether these faultlines in Auckland are active and whether they represent a significant seismic hazard,” he said.<\/p>\n
There was a common perception that Auckland was not very seismic, but that was probably because it was compared with other places in New Zealand, which was a very seismic country, he said.<\/p>\n
It had actually experienced some significant events, like the 1891 Port Waikato quake which was strong enough to shatter windows in the city, he said.<\/p>\n
The new potential faults were discovered when researchers analysed borehole samples.<\/p>\n
“Basically holes that have been drilled around Auckland to look at how the sub surface has moved both up and down below our feet through time,” Muirhead said.<\/p>\n
The morning’s headlines in 90 seconds, including why Trump says the Iran war isn\u2019t \u201cboring\u201d, and Liam Lawson\u2019s new lessons for the F1 season. (Source: Breakfast)<\/p>\n
The team divided the lines into likely faults, possible faults and possible structures – lines that showed signs of ground movement but it was unclear why.<\/p>\n
Two of the most prominent probable faults ran from the Waitemat\u0101 to the Manukau harbours, one through Avondale, the other from Glendowie to Blockhouse Bay.<\/p>\n
They had already been suspected but the latest research had shored them up and more accurately measured them, Muirhead said.<\/p>\n
Some of the possible faults were around Northcote, Birkenhead and Wiri.<\/p>\n
There were many more in the “possible structure” category which meant they needed a lot more investigation, such as in Sandringham, Newmarket and \u014ct\u0101huhu.<\/p>\n
The research said it was possible intense urbanisation could mask faults.<\/p>\n
The report also revealed Auckland experienced more small earthquakes than previously thought, but Muirhead said that was likely because there was better monitoring.<\/p>\n
The work has been partly funded by the Natural Hazards Commission which has highlighted them in its latest Resilience Highlights Report which looked into the impact of natural hazards.<\/p>\n
The commission said even though major earthquakes remained unlikley, the findings could help decide how land is used as the city grew.<\/p>\n","protected":false},"excerpt":{"rendered":"Dozens of previously unknown faultlines have been discovered under Auckland – and new work is set to find…\n","protected":false},"author":2,"featured_media":310329,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[51,8215,273,1242,111,43,139,69],"class_list":{"0":"post-310328","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-new-zealand","8":"tag-auckland","9":"tag-earthquakes","10":"tag-environment","11":"tag-natural-disasters","12":"tag-new-zealand","13":"tag-news","14":"tag-newzealand","15":"tag-nz"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/310328","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=310328"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/310328\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/310329"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=310328"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=310328"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=310328"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}