New Zealand earthquakes

English Felt earthquake
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#1

Yesterday a series of very strong earthquake hit New Zealand. We hope everyone’s safe by now.
A tsunami alert has also been launched but luckily the waves were not high enough to be too dangerous.
This sequence of earthquake and tsunamis is unsettling for a lot of people. Our thoughts are all those affected.

The National Seismic Institute has provided an aftersock forecast : GeoNet: News

Additionnaly if you have any picture of damage please share them. It does help the disaster management, other citizens and seismologists as they can then study the seismic mechanisms !

Stay safe and do not hesitate if you have any question!

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#2

How does the series compare to previous (here or elsewhere). Seems very different to ‘normal’ swarm earthquakes like the current Iceland one. It is unusual to have some many very large quakes one after the other no? The quakes are shallow to in an area more used to deep ones. Finally, seems yesterday to have triggered a number of other quakes all over (total number of quakes on map more than normal, even allowing for all the Kermadec ones) and then today, a second series all down the east coast of NZ North Island. Fascinating (and must be pretty scary for those caught up in it - as you say, hope all can cope OK)!

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#3

Dear DAC,

I’ve found this resource from IRIS Seismology:

where they address the questions you’ve raised. Have an enjoyable reading! :slight_smile:

Best regards.

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#4

Very enjoyable reading, thanks so much for the link. The IRIS website is worth keeping an eye on then, along with the daily earthquake reports from (confusingly from the Volcano Discovery website, which also has some amazing volcano stuff on it too - including guided tours, very tempting if you are wealthy enough!).

The thing that is missing is a more regional / even global? perspective on daily activity, are the various earthquake sources behaving normally or is something unusual afoot. The USGS Earthquake map and listing sometimes has explanations and give local context, but again mostly individual event focused rather than wider process explanations.

Nevertheless, the Kermadec / NZ information in the IRIS Teachable Moment was fascinating, thanks again for providing it!

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#5

You have real guided tours on Volcano discovery? :star_struck:
Have you done some?
Is it real or virtual?
Do they explain basic science of volcanos during the tours???

#6

Unfortunately, I have only seen the itinery on the website. Too expensive for me, but they do offer the chance to get close to volcanoes with an experienced guide, who I am sure would be able to provide technical explanation to those present (I don’t work for them and I am not being paid to advertise their services, I am just relating what I have seen on the internet). Problem is that volcanoes are nearly as unpredictable as earthquakes, so I have never seen an actual eruption myself. On the otherhand (more predictably), because I live in a very geologically stable part of the world (Scotland), I have not experienced a significant earthquake either! Best of luck with your geological tourism planning!

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#7

Good morning all, here are some brand and fresh news about this earthquake sequence : New Zealand sees exotic earthquake sequence - Temblor.net

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#8

Fascinating stuff, thanks!
Interesting that the article doesn’t mention the whole series (swarm) of earthquakes on the same trench, but between the original M7.3 quake and the M7.4/8.1 ‘triggered’ quakes?
The concept of dynamic triggering is what I think I had in mind when asking the original question, how big quakes can influence susceptible / sensitive tectonic settings even at a distance, essentially acting as the final straw, not necessarily breaking the locked fault(s) by itself, but doing just enough to change the remote situation and allow a new quake to occur where it might otherwise have taken much more time? This not guaranteed to happen for every big quake, but when circumstances are ‘just right’?!

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