{"id":6316,"date":"2025-09-06T16:47:08","date_gmt":"2025-09-06T16:47:08","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/6316\/"},"modified":"2025-09-06T16:47:08","modified_gmt":"2025-09-06T16:47:08","slug":"rare-northland-quake-sparks-curiosity-about-regional-seismic-risk","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/6316\/","title":{"rendered":"Rare Northland quake sparks curiosity about regional seismic risk"},"content":{"rendered":"

Micro-quakes, big questions<\/p>\n

\u201cA magnitude-1.6 earthquake is exceedingly small and we wouldn\u2019t have detected it without the densification of our sensor network in Northland that occurred in 2022-23. Areas of Northland now have network density comparable to the East Coast (Hikurangi Subduction Zone)<\/a> and Southern Alps (Alpine Fault) plate boundary regions, where recorded earthquake counts are in the 1000s per year.\u201d<\/p>\n

Since this network rolled out, six earthquakes in Northland, or about two a year, have been detected.<\/p>\n

\u201cAnd that\u2019s not for a lack of trying,\u201d Taylor said, adding that the quake gives some new insight into the dormant faults in Northland.<\/p>\n

\u201cThe earthquake tells us that just because you\u2019re far away from the plate boundary doesn\u2019t mean there isn\u2019t stress accumulating in the crust.\u201d<\/p>\n

Taylor said Earth Sciences New Zealand doesn\u2019t categorise any faults in Northland as active, but there are plenty of faults in Northland from when it was active tectonically some 10 million years ago.<\/p>\n

\u201cFaults developed then to accommodate compression, like what is happening on the East Coast today. This earthquake may have happened on one of the old faults or just somewhere in the crust.\u201d<\/p>\n

Despite the quake this week, Northland\u2019s earthquake hazard hasn\u2019t changed significantly.<\/p>\n

\u201cWe expect earthquakes everywhere and this just reminds us that they can happen in Northland, as they did in 1963-1964 around Mang\u014dnui and Peria west of Whangaroa, when a period of seismicity produced a magnitude-4.8 and many smaller earthquakes. Earthquakes have also occurred in the region sporadically since then, which is what we expect for a stable region like Northland.\u201d<\/p>\n

Looking forward, he said the trend of sporadic, small earthquakes is likely to continue as a result of the many old faults in Northland.<\/p>\n

\u201cMore earthquakes will happen in Northland, but I expect the trend of the last ~80 years will continue for a few million more at least. Unfortunately, that doesn\u2019t mean a larger earthquake than what we have seen isn\u2019t possible.\u201d<\/p>\n

\u201cThere are many old faults in Northland and, as the recent earthquake has shown, there is still enough stress building in the crust to break it. The good news is it could be a long time before such an earthquake happens, if it ever does.\u201d<\/p>\n

Why Northland is different<\/p>\n

Northland\u2019s distance from the plate boundary is what sets it apart<\/a> from other parts of the country that are more seismically active.<\/p>\n

\u201cNorthland is sort of \u2018behind\u2019 all the action tectonically, especially in the Far North, because the compression and extension from plate tectonics is being accommodated elsewhere,\u201d Taylor said.<\/p>\n

He said people in the region should be more aware about earthquake risk, despite the region\u2019s low activity.<\/p>\n

\u201cIt\u2019s something everyone should be aware of and know what to do in an earthquake and what they might need to do in the time afterwards.\u201d<\/p>\n

Drop, cover and hold\u202fduring a large earthquake, Taylor advised.<\/p>\n

If it is long or strong, get gone, the official advice suggests.<\/p>\n

If you are near the coast or a lake and feel a strong earthquake that makes it hard to stand up or a weak rolling earthquake that lasts a minute or more, move immediately to the nearest high ground or as far inland as you can, out of tsunami evacuation zones.<\/p>\n","protected":false},"excerpt":{"rendered":"Micro-quakes, big questions \u201cA magnitude-1.6 earthquake is exceedingly small and we wouldn\u2019t have detected it without the densification…\n","protected":false},"author":2,"featured_media":6317,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[1443,8212,8208,6752,8215,305,111,43,139,529,1067,69,1523,8206,8205,8210,8213,381,5914,7192,8209,8214,8207,5157,8211],"class_list":["post-6316","post","type-post","status-publish","format-standard","has-post-thumbnail","category-new-zealand","tag-about","tag-anyone","tag-curiosity","tag-earthquake","tag-earthquakes","tag-have","tag-new-zealand","tag-news","tag-newzealand","tag-north","tag-northland","tag-nz","tag-over","tag-quake","tag-rare","tag-rattled","tag-recorded","tag-region","tag-regional","tag-risk","tag-seismic","tag-sparked","tag-sparks","tag-windows","tag-woken"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/6316","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=6316"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/6316\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/6317"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=6316"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=6316"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=6316"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}