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NZ Earthquake

mcb1

Guys/Gals

Just a quick update on the major Earthquake that struck NZ north of Christchurch just after midnight.

 

They have decided that there was two quakes and they are still deciding if it was along the Hope faultline which runs SW to NE and forms the hills that are between the Southern Alps and the east coast.

It would seem that this triggered many others right up the North Island so the effects were felt widespread.

 

 

I'm in Chch and was up at the time. It went on for 2-3 mins which is much longer than the previous ones.

The closest place is Kaikoura and it has caused some damage to houses, but has currently cut the road link that goes up the east coast (State Highway 1), and damaged other roads that could form an alternative route.

 

There was a Tsuanami warning issued, but got downgraded to a coastal warning.

Unfortunately these warnings end up much less than predicted, so if we actually get a real one, then I'm afraid many will ignore it.

 

 

For those that haven't experienced Earthquakes, they can be very disturbing to some people.

There is often little/no warning and while it might be a little bit of shaking at first, you have no idea how long it will last, or if it will get worse.

 

 

NZ sits on the junction of two plates and one is going under the other. The movement is constant, but various bits get stuck and then suddenly release as the stress overcomes the friction.

This release often results in extra loading on another part and triggers an aftershock which can be almost as large.

So far there have been 50 or more aftershocks in and around the area, so you get no rest from them.

GeoNet - Quakes

As you can imagine you lose power, your house gets trashed and you get no rest, so it's quite stressful in the affected are.

 

 

The christchurch event in 2010 had around 14,000 aftershocks varying down to only just detectable without instruments.

So this will last for some days and it may trigger more events.

 

 

 

If you have friends and relatives in NZ, do try to make contact but appreciate that cellphone systems get overloaded and texts are the best way to contact them.

 

 

Cheers

Mark

  • Hi Mark,

     

    It's good to know that you are safe.

     

    In recent times it seems that different parts of the faults are shifting causing havoc.

     

    I used to live in Wellington and was used to the frequent small tremors (Yes - I'm part Kiwi) and many may not know that NZ is very geologically young and frequently subject to these seismic events.

    Most of the houses in Wellington are made from timber to accommodate this movement.

    Christchurch on the other hand had many buildings made from masonry that can't withstand such movement and the area was subject to liquefaction.

     

    According to current theories NZ has been very active for the past 1.8 million years. Even today the plate boundaries move about 2-3 metres every century.

    NZ has quite a few Super volcanoes with the most obvious one being Lake Taupo in the centre of the North Island which apparently last erupted only 1,800 years ago and there is scientific speculation that it may erupt or its activity will cause a massive earthquake soon so much so that emergency protocols are being formulated.

  • I'm really happy to hear you and yours are safe, Mark.

     

    Hope you can get everything back to normalcy quickly.

     

    -Nico

  • Hi Mark,

    Thank you very much for posting so quickly as we were very worried about you and your family. I hope things settle down quickly. Millie comes from Guatemala and survived a serious quake in 1976 so she knows what you are going through. Please keep us posted.

    John

  • in reply to jw0752

    Thanks everyone.

    The residents of Christchurch know what to expect after an earthquake of this magnitude.

    There have been more than 600 aftershocks greater than magnitude 3 in less 23 hours.

    GeoNet – Quake Search

    image

    Kaikoura is just south of the biggest cluster, so they have been hammered.

     

    I stole these from facebook

    image

    This is State Highway 1 which is the major highway heading North South (think M1) and along the coast there are 4 tunnels.

    2 of them pass under this rock outcrop, and the railway runs through a bit deeper and exits in the concrete wall like feature running along the cliff edge.

     

    imageimage

    As this picture shows, the inner tunnel is buried. Now bear in mind these two tunnels accomodate truck plus trailer configurations (B train) that have to be straight as there is zero clearance for them, so there is a large amount of road covered.

     

      imageimage

        This one is the tunnels further south from kaikoura. The next image shows part of the road between the tunnels.

        Thanks to Google Earth this is what they should look like.

    imageimage

     

     

     

    These come from this post https://www.facebook.com/rebuildchristchurch/posts/1423992670959138

     

    imageimage

         These are north of Kaikoura, and if you look carefully in the first one you will see the railway line that used to be on the far side of the road is actually in the water.

     

    imageimage

    That will take a few truckloads to remove.  The railway line is in a tunnel around this section, so they can get some access to both sides to speed it up.

      image

    Thanks again to Google Earth the amount of material is enormous.

     

     

     

    image

    I'm not sure if this is in the same area, but you can see the railway line has been pushed out into the sea.

     

    image

      This image was a screenshot from a video, and shows a whole section of line shifted sideways.

      The line actually goes in a sweeping bend on the other side, hence it had a bit of spare line to move.

     

     

     

    Lastly there was concern amongst those stuck between slips with little high ground and a Tsunami warning.

    From their observation the tide had receeded leaving the foreshore uncovered.

     

    image

    These are Paua (Abalone in Australia) are are never out of water.

     

    The actual cause is that the seabed has risen by 2m all the way up to Blenhiem that we're aware of.

     

     

    There is more roading damage in the hills, and further north there is a major step in the road where vertical displacement has occurred.

     

     

    Cheers

    Mark

  • in reply to mcb1

    Wow, that's scary. That'll take a lot of work to get straightened out again.

     

    Incredible that the seabed rose by 2 meters!

     

    Thanks for sharing image

     

    Cheers,

    -Nico

  • Mark,

     

    The whole element14 team is relieved  to hear that you are safe. Thanks for sharing!

     

    Dave

  • Glad to hear you are OK.

    Earthquakes can be terrifying and we in India are no stranger to quakes. I make regular trips to the mountains and landslides and falling boulders are unfortunately a regular scene however they are every bit scary each time.

     

    Its always better to be prepared and I hope you guys dont face any serious events.

     

    Stay safe and keep us updated.

    Cheers,

    IP

  • It's always amazing how strong these can be. Glad to see you are O.K.

  • Hi Mark,

     

    When I heard the news I was worried about you, but figured it  would be better to wait because I did not know how much impact there was to your infrastructure.

     

    Glad to hear that you and your family are safe.

     

    From what I have seen, the damage is pretty bad in some places, but all in all, it looks like NZ survived with minimum casualties.

     

    Let us know if there is anything we can do to help.

     

    DAB