Seeing earthquakes

Seeing earthquakes

Dr Hamish Campbell, Te Papa’s geologist in residence from GNS Science, shares his experience witnessing the green lights in the sky following the 2016 Kaikoura earthquake.

Dr Hamish Campbell
Dr Hamish Campbell. Courtesy of Friends of Te Papa

Green sheet lightning

I was driving home to Wellington from Auckland late on Sunday night after having had dinner in Taupo with Dinah and our children Niamh and Riley.

Petrol and coffee in Bulls just before midnight and then onwards beyond Sanson along that long straight stretch of road heading southwest.

There was a lovely full moon and an almost clear sky with only a thin veil of wispy high cloud.

Suddenly the sky lit up on the horizon with what I would describe as green sheet lightning. Weird stuff…and no rain clouds evident.

It did not last long, a matter of seconds. It was directly ahead of me, far to the southwest and high in the sky, widely spread and seemingly moving from west to east.

Time went by, and I stopped thinking about it.

I continued in my radio-free car and arrived at my home in Ngaio at about 1:15am. Straight to bed…only to be disturbed by my mobile.

It was a text from my daughter Saskia asking: ‘Are you okay Dad?’. Such a strange question at that hour of the night from Osaka! I replied: ‘Of course!’.

So it was that I learnt of the magnitude 7.5 Kaikoura earthquake from Saskia in Japan – there is nothing like social media.

And it then dawned on me that the green lightning that I had observed was almost certainly an atmospheric effect caused by the earthquake.

I had SEEN an earthquake. Yay!

The phenomenon is real

As a geologist, over the years I had heard of atmospheric effects associated with earthquakes.

Various theories abound including a gas release explanation (yeah right!), an instantaneous ion discharge effect that translates into electrical light emission in the upper atmosphere (much more likely), and so on.

Poorly understood and commonly poo-pooed as an illusion, I can now vouch first hand for this phenomenon being real.

Furthermore, my colleagues at GNS Science, Sarah Milicich and Wendy Saunder,  also witnessed this green light phenomenon from their homes in Wellington.

Video courtesy of Caters News Agency

What to expect now

This earthquake is the largest recorded in New Zealand since the magnitude 7.8 Dusky sound earthquake in 2009.

However, the Kaikoura earthquake was much more widely felt and more damaging because of its location in central New Zealand.

According to my colleagues at GNS Science and our surveillance arm GeoNet, the aftershock sequence experienced so far is considered to be normal for an earthquake of magnitude 7.5. The frequency is diminishing as expected.

However, the possibility of a large aftershock of between 6.0 and 6.9 within the next 30 days is very likely.

There is also a possibility of the Kaikoura earthquake sequence triggering an earthquake that is of greater magnitude than magnitude 7.5 within the next 30 days but this is considered very unlikely.

As for Wellington, there is no evidence of an impending large earthquake of similar size to the Kaikoura earthquake at this stage but we cannot rule this out.

We cannot make a calculation to predict this but the chance of a further shock in the Wellington area has increased somewhat since the Kaikoura earthquake.

How Te Papa held up

Fortunately all Te Papa’s staff came through the earthquake unharmed. The quake has not had any impact on the building’s structure and the seismic restraining work carried out at the museum in recent years had protected the collections.

21 Comments

  1. To Robin Warnes: Sorry to be so late getting to you. Your description at Raumati Beach – does this mean The flashes were out to sea? This is scientifically quite important
    Neil Whitehead

  2. Hi Hamish. Just a belated query about the earthquake lights. I now have very many accounts and they differ about colour. Some of the webcam videos show what I would best describe as a teal colour, and wonder if you might agree the colour might be a pale blue-green. If not, would you be able to give a shade for the green, e.g. grass green, or something?
    Reports and videos have come in from as far away as Hamilton and Napier.
    Regards,
    Neil

  3. Excellent way of explaining, and fastidious post to obtain data on the topic of my
    presentation subject, which i am going to present in school.

  4. Congratulations on you luck in observing this effect.

    (I’m far from an expert)
    My guess would be the pizeoelectric effect similar to “click” gas igniters. This involves “squeezing” out the electrons from a crystalline material by rapidly striking it.

    If my theory is true, I wonder if the Lightning detection network would have registered the electromagnetic energy of the discharge. My understanding is that it measures the propagation delay from lightning strikes to triangulate where they occurred with high accuracy.
    In this case it wouldn’t be so tightly defined so was probably rejected as noise.

    This might be the beginning of electromagnetically detecting earthquakes… You heard it here first.

    Kind regards

  5. Hi Hamish,

    Firstly, congratulations on seeing this fascinating phenomenon.

    I was amazed to see so many accounts of it in the accounts of c19 accounts of NZ earthquakes.

    (I saw what i thought was a distant torch shining onto our curtains, but never thought to look ‘up’ for the source.)

    But, I’d no idea that Earthquake Lights were such a ‘pop phenomenon’, or that it was an object of skepticism https://skeptoid.com/episodes/4534 .

    Even EQC have funded studies to look at anomalous ionization of the atmosphere as a precursor to seismic events. http://www.eqc.govt.nz/sites/public_files/3789-Ionospheric-earthquake-precursors.pdf .

    Fascinating stuff.

    Cheers
    Paul

  6. Very interesting and amusing account, Hamish :-). According to my calcs, to be observable from Foxton-Sanson area, the lights (if above the epicentre) would have to be at about 10 km altitude – which is not impossible. The question of timing arises: at, before or after 12.02 a.m.? light would get there very quickly but gases, ionised or ignited would take much longer – they could have been accumulating there of course, and then ignited. Any thoughts?

    1. (from Hamish Campbell)
      Dear Stuart,
      I quite agree: it had to be very very fast …more or less instantaneous in fact…and hence extremely unlikely to be related to a gas escaping from the ground.
      I did not notice the time so a unable to comment in any meaningful way. Sorry!
      I suspect that the answer likes ‘in the rock’. Imagine the effects associated with grinding rock against rock at the speed of 3 kilometres per second or in other words 10,800 km/hr. That is what we are dealing with.
      Now, think of what we can achieve when striking a match…this is probably the nearest common every-day activity (well…it used to be) or analogy that I can think of. All we do is create friction, match against the box, and we generate a chemical reaction that instantaneously releases intense heat and light.
      The Earth’s crust does something similar.
      Cheers, Hamish

  7. Yes, I say lightening through my bedroom window at Raumati Beach during the earthquake. To me it looked like lightening as in a thunderstorm. I realised very quickly that it would more than likely be static charge generated by the quake. This is a very rare sight and I feel very lucky to have seen it.

    1. Yes, I saw lightening through my bedroom window at Raumati Beach during the earthquake. To me it looked like lightening as in a thunderstorm. I realised very quickly that it would more than likely be static charge generated by the quake. This is a very rare sight and I feel very lucky to have seen it.

    2. Author

      Dear Stuart,
      I quite agree: it had to be very very fast …more or less instantaneous in fact…and hence extremely unlikely to be related to a gas escaping from the ground.
      I did not notice the time so a unable to comment in any meaningful way. Sorry!
      I suspect that the answer likes ‘in the rock’. Imagine the effects associated with grinding rock against rock at the speed of 3 kilometres per second or in other words 10,800 km/hr. That is what we are dealing with.
      Now, think of what we can achieve when striking a match…this is probably the nearest common every-day activity (well…it used to be) or analogy that I can think of. All we do is create friction, match against the box, and we generate a chemical reaction that instantaneously releases intense heat and light.
      The Earth’s crust does something similar.
      Cheers, Hamish

  8. My husband and I saw the lights clearly from Stokes Valley. I thought it was lightening and my husband ( an electrian ) thought it was a substation blowing up. I thought they had to be associated with the earthquake because they were visible when the rocking was at its most severe. When I read about them the next day I thought it strange that we saw them southwest when the quake was southeast from where we are. It was an incredible sight I will never forget and as terrifying as the earthquake was I feel privileged to have witnessed them.

    1. Author

      Thanks for your thoughts Mary.
      I too feel very lucky to have witnessed the green light effect.
      Cheers, Hamish

  9. Did the Zhang heng earthquake recorder work?

    1. Author

      Dear Naomi,
      Dear Naomi,

      It would have were it set up in working order!
      It is not on display at Te Papa at present.
      It will be carefully stored and wrapped up at present.

      Cheers, Hamish

  10. Great blog Hamish 🙂

    1. Author

      Thanks Rebecca!

      Cheers, Hamish

  11. I live in Waikanae and was woken by the earthquakes, my room was filled with several intense flashes of blue green light, at first I thought it was lightning, but the colour was strange and there was no following thunder or even clouds. I am really happy I saw the earthquake ! Isn’t Mother Nature amazing.

    1. Author

      Dear Linda,

      Thanks for those thoughts.
      Yes, she is amazing!
      Soooo interesting and so much for us yet to learn and understand.

      Cheers, Hamish

  12. In Maori this phenomena is called Rūrangi. Rū being earthquake and rangi being the sky. Wow such an amazing sight to see Hamish. Glad you didn’t notice it while driving home.

    1. Author

      Thanks Ati! That is a lovely word. I must remember it.
      Cheers, Hamish

  13. On talk back radio with Radio Live a caller rang in from Wanganui saying he had seen the lights… TVONE said tonight Wellington measured the quake as 7.8 in the city…and I slept through it all thank goodness, am in Wairarapa

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