18 November 2016

2016 Kaikoura Earthquake



Well I said shake, rattle and roll
I said shake, rattle and roll
I said shake, rattle and roll
I said shake, rattle and roll
Well you don't do right
To save your doggone soul
Shake, rattle and roll
- Jesse Stone


Moving to New Zealand, we knew we were moving to a geologically active area of the world. We knew it intellectually, but this week we got to know it viscerally.

In January/February 2014, we came to New Zealand on holiday. We had an idea we wanted to work and live here, so we headed across the Pacific for a scouting trip and for a holiday to experience as much of New Zealand as we could before committing to a contract sight unseen. We had just under two weeks, and we knew we couldn't see everything, so we made plans to hire a caravan and explore the North Island. The caravan idea came about from the suggestion of friend with whom I worked and occasionally played golf. It was on the golf course that he told me about his trip to NZ and about "caravaning".  And it was during that conversation that I first heard about New Zealand and earthquakes. He had been to NZ a couple of years before and had wanted to go to Christchurch during his visit. Unfortunately, he was unable to do so because ChCh experienced a magnitude 6.3 earthquake in February 2011, just before he arrived.
 
The epicenter of the Christchurch earthquake was close to City Centre (10km/6mi) and it was relatively shallow at 5km/3mi underground. The quake only lasted about 10 seconds but it caused massive damage. In the downtown core, 45% of the 3000 buildings were eventually tagged as unsafe and by February 2015, 1240 had been demolished. 170K buildings and homes were damaged and 11.5K required demolition. Six years later, the city has only partially recovered. The economic impact has been nearly equal to that of Hurricane Katrina but because of insurance disputes many people continue to live in severely damaged homes.

On our trip to New Zealand, we didn't experience any earthquakes (that we noticed), but we did take advantage of the fact that NZ is geothermically active. One of our first stops was at Hotwater Beach. Its name comes from the underground hot springs that filter up through the sand. People dig holes in the beach that then fill up with hot water. The water can get so hot as to be unbearable. We didn''t have shovels so digging holes was somewhat laborious. We had a similar experience on the shores of Lake Rotorua and this time we had digging tools. Our beach "hot tub" was so hot we had to dig a channel to the lake to allow cooler water to flow in.


Adoptee Beach Hot-tub Proud diggers


I have felt earthquakes in other places I have lived and traveled, but they were more of the "what was that?" kind of experience and then only later finding out there had been an earthquake. Kari has never been through a quake before this week. A few minutes after midnight on 14 Nov 2016, I awoke to the bed shaking. It wasn't much, like someone vigorously scratching an itch, but it was going on a little long and I was getting annoyed. I rolled over to ask Kari "What the hell?" and realised that she wasn't in bed. Just about that time, I heard a rhythmic clacking. It took a second or two to recognize it as the sound of the wooden knobs on the blind pulleys smacking against the wall. I figured out pretty quickly that it was an earthquake. That's when the fun began. The bed started a slow roll, yaw, and heave like a small boat in moderate seas. When the bed started heaving, I actually got a little sea-sick. Afterward, I couldn't help but compare it to the bed scene in The Exorcist ... minus the priests and demons, of course.    


The Exorcist


Kari turned on the hallway light just about then and I called out to her to go lie down with Little H. I laid there in bed, heaving and rolling, listening to the house. If I heard anything crash, crack, or break, I would have to get my family out of there. I figured we were otherwise safest lying down on our beds. The entire episode lasted a minute or two, but it felt much longer. I was eventually able to fall back asleep. Kari was up the rest of the night.

Here's Kari's experience in her own words ...      
I woke up during the night for my usual bathroom break ... too much water before bed, after effects of pregnancy, age ... who knows, but this is part of my nocturnal life now. Anyone who knows me is well aware of my eyesight and the fact that it borders on legal blindness. With that being said, I was out on my own ... no contacts, no glasses, "Costco walking" (a Grant term ... ask him about it) and praying I make it the 20 or so feet to avoid the involuntary void. As I reached the bathroom door, I heard this bizarre noise that was clearly affecting our roof. It initially sounded like large rain drops pelting the roof, but then I thought maybe it was someone or something outside our bathroom. This further delayed my appointment with the toilet, as I was truly frightened and did not want to open the bathroom door and proceed. Fear of stress incontinence ruled and I made my way to the toilet (sorry for the visual).
As soon as I sat down, the whole room and house started swaying and it felt as if the floor was receiving rolling waves. It only took me a few seconds to realize this was an earthquake. Adrenaline kicked in, and damn it, I could no longer pee. Without meaning to sound dramatic, I found myself unable to call out to Grant, another bizarre moment because I never shut up. I think I can be described as one of the most non-dramatic individuals, so please bear with me ...
I stood to try and make it back down the hallway and to our bedroom. This posed a problem ... I have been on a couple of cruises, and certainly spent many years on the Gulf of Mexico fishing with my late father, but never in what I considered rough seas. What transpired as I walked from the bathroom to the hall would be exactly what I imagine it would be if you were trapped on a boat in a squall or rough seas. I could barely keep my balance. Crawling may have been a better option, but didn't think of it at the time. With the bathroom light off, I turned on the hallway light and set my sights on making it back to our bedroom. It was then that Grant called out to me to go to Little H's room and be with her. As I laid there, the wooden blinds in the windows relentlessly banged against the window and frame. She has a pendulum light in her room and with each sway, I feared it would be broken ... it came that close to her ceiling.
In retrospect, I am sure the quake woke me, not my bladder. This was one of the most eerie and nearly indescribable experiences I have ever been through. Little H never roused, but asked to be woken if there is another quake. I told her I hope there won't be, but if so, I would never wake her ... she would have been terrified. In fact, an aftershock came the next evening while we were watching TV. I also happened to be on the phone with my brother. I turned to Little H and asked if she felt the quake and she said 'yes'. She proceeded to ask if we would be ok, to which I replied 'yes'. She hasn't brought it up anymore and was so brave and helpful when I packed a 'grab and go' bag and parked the car outside of the garage for the night. This definitely was not on any of our bucket lists, but happy to mark it off.
We have been avidly following the news and Geonet online. This event was actually 2 overlapping earthquakes involving 6 fault lines. In total, it lasted about two minutes, but the two events overlapped for about 50 seconds. Interestingly, not only was it two separate events, but the events were two different kinds of earthquakes.  


Kaikoura Quake fault lines
With more recent analysis, it was upgraded to Magnitude 7.8        


Some of you may know me from another life ... one where I studied Marine Science and worked for an oil exploration company mapping geological structures under the sea floor. Please indulge me while I totally geek out on this stuff. For my non-science/geology/oceanography friends, earthquakes occur when parts of the Earth's crust called tectonic plates rub up against each other. These plates can interact such that one plate gets forced under while the other rides up (Convergent), both are lifted and forced apart (Divergent), or they slide along each other (Transform).


Tectonic plate movement

Quake changes


Movements along fault lines are felt as "earthquakes" and are described as a Normal Fault, a Thrust or Reverse Fault, or as a Strike-slip Fault.


Earthquake types

Fault types


The 2016 Kaikoura Earthquake was one of the largest in recent New Zealand history. The Magnitude 7.8 earthquake occurred along 6 fault lines and was comprised of two separate events; a Thrust and a Strike-slip. It has had huge environmental and economic impacts. Two people died and there was significant damage to buildings as far away as Wellington (150km/95mi) on the North Island. Multiple slips (rock slides) have cut off the only major road in and out of Kaikoura.  


Slip over highway
From the Labour.org website (I could not find photo credit)


Notice the bent railroad tracks ...

Train tracks bent Road damage
From NZ Herald website. Left photo credit Mike Scott. No photo credit available for image on Right.


Road damage ...  

Road & Track damage
From the GNS Science web site. Photo credit not available.


Locally, the rail line between Palmy and Wellington was shut down and roads between here and there were closed. There were some heavy rains South of us, and that combined with the loosening of the ground from the shaking led to some pretty significant flooding. We didn't have any damage, and other than getting a little motion sickness (no puking though), it didn't seem to affect us much, until the consequences of the closures were brought home to me at work the other night.

On Tuesday night, almost 48 hours after the earthquake, I was working in A&E. We got a radio report from one of the medical helicopters that they would be landing at our facility. On board, they had a patient with an ongoing STEMI (heart attack). He had been seen earlier at another hospital to the north of us. His STEMI had been diagnosed and he had been treated appropriately, even given thrombolytics (medicine to open the blockage in his heart) but was continuing to have pain and his ECG (electrical activity of his heart) was still abnormal. They were transferring to Wellington by helicopter to get him to a facility where they could surgically open the blockage.

When it comes to muscle damage from ischaemia (lack of blood flow), time matters. Unfortunately, the weather further South was so bad, it was unsafe for the helicopter to continue flying. Normally in this situation, we would package him up to continue his transfer by ground. However, the roads to the South of us were also closed because of flooding and slips due to the heavy rains and earthquake. There was nothing else we could do for this poor guy but watch him and hope. Just before transferring him to the inpatient CCU (Cardiac Care Unit), he told us that his pain was gone and a repeat ECG showed normalization of the wave forms. It took a while, but it would appear the thrombolytics he was given prior to his helicopter ride finally had an effect.

I always imagined that an earthquake would be like what you see in the movies ... short and violent. From what I have been reading, the kind of long-period wave activity we experienced is more typical of large earthquakes and this one was also unusually prolonged. I have never been through a quake this big before, but I'm glad we did and that everyone is alright. I will learn from this experience ... how to recognize it, what to do, what not to do, and how to be better prepared.



She'll be right, mate ...

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