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Earthquake notes


Pic: moon over Japan moments before tsunami. From Alan Siddons


GNS are our country's qualified scientists. This article is an attempt to re-interpret what GNS have provided in their links. But it is intended only for those who wish to read it, and wish to be reminded there are GNS warnings of more earthquakes in the Christchurch region.

This page is created in consideration of those who have asked for it through emails to me. I am worried about what may come to the region in the next two weeks if there are no contingency plans. There is an air of relaxation at the moment, but I believe this may be premature. My opinion is that the better time to relax is after April.


I am not a GNS scientist, but there are many websites that take it upon themselves to make comments regarding their work, and I am just one more. This is a very tricky area, that is, whether to discuss and suggest what appear to be recent patterns and let readers see a trend, or keep quiet in case extra stress may be caused. Everyone appreciates that the earthquakes have caused enough stress for everyone, for possibly a lifetime. I have opted to state what I believe also for the greater good. But right now this is a chance for anyone who does not wish to read what I believe to press the exit button. No one has to believe anything they read here. And I very much hope that my own opinion is entirely misplaced.


This is not a call for people to flee Christchurch. It is just a plea to take care at or near the coast over the next fortnight.


And I do apologise if this message causes inconvenience, hardship or stress that wasn't already there. I am only sincerely trying to help.


So here are only my observations about past patterns as posted by GNS as part of their published data, and what is here does not constitute predictions of earthquakes. No one can be certain of anything in the future.  I believe that any predictions are only made, or not, by the reader. This article is not intended for publicity purposes, and neither is it to generate income, for I personally have never made one cent from earthquake comments or suggestions.


(This is a page covered by international copyright and I do not give permission for reprinting by any media.)


The reason for posting this now is that we are coming up to the kingtide time just before Easter, and I think it is a potentially powerful one. 



What does earthquake science tell us?   

I have the utmost respect for all scientists, including Dr Berryman, of GNS, who is doing an extremely difficult job. My heart goes out to him and his colleagues, sincerely, as they appear to be caught between the discretive requirements of politics and the called-for transparencies of science. I think for scientists the situation changes every day, making the study rather obscure going forward. Older concepts have had to be revised to accomodate developments that were not expected. It is perhaps a time of change for the whole seismic scientific community. e.g. there are several international geophysical conferences now in the planning stages, in Brisbane, Italy and India, that are questioning the whole theory of plate tectonics.

Mainstream earthquake science does seem to have some serious theoretical issues. The following three contradictory claims have confused me, at least.


Claim 1: that earthquakes WON’T occur can be predicted       

"Dr Kelvin Berryman stated that the fault lines under the Lyttelton Tunnel were too small to worry about and there would not be another damaging fault for 200-600 years.."  (this link seems to be now unavailable)
"The Greendale fault line from the Darfield quake was a previously unknown fault.."
“Sir Peter Gluckman said: "There is no added risk of a quake on March 20th ..”



Claim 2: that earthquakes WILL occur can be predicted


“Based on the earthquake rule, Christchurch should now expect an aftershock measuring between 5 and 5.3 in magnitude  



"There still remains a possibility (around a five per cent chance) magnitude 5 or larger earthquake could occur in the Canterbury area today, so be prepared," Dr Berryman said.


Coming weeks
"What sort of numbers can we expect in the coming days? Below is a table that shows the number of aftershocks that have occurred and how many we expect in the coming weeks:"


0-40 years

"According to the GNS website, there is a strong likelihood of a Magnitude 8 earthquake on this fault within the next 40 years."


0-50 years

Otago University geology professor Richard Norris said a huge earthquake, 8 on the Richter Scale, would hit the South Island within the next 50 years. A magnitude 7.5 or 8 earthquake is expected to occur on the Alpine Fault about once every 300 years and it has been about 300 years since the last one.


50-100 years

"It is possible to estimate where big earthquakes are likely in the next 50 to 100 years, based on geological investigations and the historical record of earthquakes"   



Claim 3: that earthquakes WILL or WON’T occur cannot be predicted

“An earthquake can NOT be predicted.. the most successful earthquake prediction to date is: "The next major earthquake in New Zealand will occur eventually". “


“The overwhelming consensus of the meeting was that earthquake not possible at present.”


“it is not possible to give specific predictions about aftershocks in terms of severity, location and timing.”




What is useful?

There is understandable bewilderment, and it depends what you choose to read. Scientists said after the 7.1 that another damaging one would not occur and one did. They said one would not come on 20 March, and five 5.1’s arrived, along with about 40 others, some 4+'s around lunchtime. They have said some big ones are coming soon and are even overdue. At the same time they have also said earthquakes can’t be predicted. Assuming all of these statements are correct in their own way, what information can be actually put into practice for safety reasons for families???




I agree with all of the above

I think it is true that a big earthquake will arrive..eventually (as the Taupo City Council has stated).

I think it is also true they cannot be predicted if prediction means exact place and size. I think it is also true that you cannot exactly, to the minute, predict when summer rains will come. But you can predict that summer rains will come eventually and you can tell from various signs what the patterns are indicating.  You don’t have to be a qualified scientist to know your own observations.  Neither do you have to be a qualified scientist to be allowed to look back at patterns that have been made available by qualified scientists.

So let’s do that.



The pattern thus far

This is the recent public record of when each next biggest event has occurred in Christchurch over the past 7 months. I am listing the main tide days and dates and their associated earthquakes. The days are focus range dates and have a leeway of a day or so, just like weather forecasts. Focus dates imply increased likelihoods.  I copied down all of the below from the experts’ websites, and they can be verified here:


September 2010

3rd-4th (neap tide) a 7.1mag on 4th (biggest, but also many others >5mag),

8th-11th (kingtides) a 5.0mag on 8th,

17th-18th (neap tide) a 4.6mag on 18th


October 2010

2nd-3rd (neap tide) a 5.2 on Oct 4,

8th-10th (kingtides) a 4.2 and 4.4 on 8th,

16th-18th (neap tide) a 5.1 on 19th


November 2010

1st (neap tide) a 4.6 on 1st,

6th (kingtides) a 4.6 on 7th,

15th (neap tide) two 4.8s on 14th


December 2010

6th (kingtide),

15th (neap tide),

25th (kingtide) a 4.9 on 26th


January 2011

14th (neap tide) a 4.0 on 17th,

20th-24th (kingtides) a 5.1 on 20th,

29th (neap tide) a 4.0 on 28th


February 2011 

4th-5th (kingtides) a 4.6 on Feb 4th

11th-12th (neap tide) a 4.0 on 10th,

20th-21st (kingtides) a 6.3 on 22nd 

28th-1st (neap tide) a 4.6 on 1st


March 2011

12th-15th (neap tide) a 4.2 on 12th, a 4.1 on 14th,

20th-23rd (kingtides) a 5.1 on 20th

26th-30th (neap tide) a 4.3 on 26th, 4.2 on 30th


April 2011

4th-6th (kingtides) a 4.0 on 4th in Christchurch.

12th (neaptide)  

18th-22nd (kingtides

26th-30th (neap tide)

Updates: on 7th, a 7.4 in Japan and a 5.2 at Castlepoint, o n 11th, a  5.1 at Dannevirke, on 16th a 5.3 in Christchurch; on 24th: 4.3mag, 39 tons, 15.5km, Lincoln; on 26th: 4.1mag, 18 tons, 9.5km, Lyttelton.   



To work out kingtides go to



Noting the latest significant seismic events:
A 5.2 mag earthquake on 7 April, at Castlepoint, (kingtide related).
A 5.1mag earthquake on 11 April, around Dannevirke, (neap-tide related)
Therefore if past patterns are anything to go by, we might expect at least a 5+ in the next kingtide range spanning 16th-22nd. As to where, we can surmise that S Canterbury to the lower North Island may be considered most at risk, being the most recently active region.

Update as of 16th: a 5.3mag earthquake, 1 kiloton energy on 16 April, Port Levy, east Christchurch, (king-tide related)


Christchurch residents should make up their own minds about what to do .

Are we in for an earthquake/ tsunami event in less than a fortnight’s time? These are not predictions. I have shown only the GNS-recorded pattern. From the patterns r eaders are free to make their own predictions. But it is important that we are all as upfront as possible, and as unconfusing as we can be, or we have no science, only pseudoscience. Civil Defence have announced an extension of their watch to at least the start of Easter.



So is/was there a pattern?

Scientists have said no.  

But I suggest the reader be the judge.


  • For the bigger earthquakes over the past 6 months, were the danger days the neap tides on either side of the kingtides, or alternatively at times around the kingtide itself?

Again, let the reader be the judge. Perhaps scientists who doubt this might want to take another look at the above Christchurch data record.


  • Since 4 September did every largest earthquake since the previous one occur in, or coming up to, the kingtide times?

Once again let the reader be the judge. The website links have been quoted.


  • Were the timings on the prone-days in just about every case usually from mid-tide leading down to or around the low tide?

We can easily let you be the judge by going to .

This great website accesses all tide days.


  • Were the neap tides on either side of each kingtide also "hot"? look again at the above list.
  • If so, were they because of the increases in land-tide heights? 

It is a theory I happen to think has relevance, that is, that the main tide of the planet is the land-tide, and that the water-tide (the only one we can actually see) is secondary and is only a consequence of the land daily going up and down as pulled by the Moon; and it seems most likely to go in opposites such that when the the land is upper-most, the water is downer-most, and interpreted as a low-tide time. I think that as it is the land-tide that brings stresses deep within the Earth the timings may be indicated visually by the sizes of the water tides. I also think that the neap tides on either side of powerful perigees - in association with sunspot numbers -are times to watch (e.g. the days of the 7.1 and also Japan's 7.9+tsunami) because of the greater land tides then. So we have certain neaps and king tide days and then down to low tide times on the actual day. Sometimes a day or two on either side might need to be granted because some stresses would require building to a breaking point before an event presents itself at the surface of the ground. There are other websites of studies done internationally around this topic, and so we can let the reader be the judge. 


But until seismology looks at this theory and starts discussing the possibility that there is indeed a land tide, then finding out how deep this land tide extends, then daily monitoring it as we do the sea-tides, we won't really have a system of early-warning instrumentation that might point to stresses. You could say that sea-tide stress points to erosion, which doesn't claim lives, and yet coastal managers want to study the cycle. Equally land-tide stress points to earthquakes, which do claim lives, so why would we not want to discover that cycle? In short, although scientists are doing their best, maybe they are confused and frustrated because they may be looking in the wrong place for answers to their questions. They appear to be gazing at old scars in hillsides and wondering when a future earthquake will use the same exit point. Well, this indeed may not be for 3000 years so they are not incorrect. Meantime though, it's a case of uh-oh,where did you come from? as major earthquakes pop up in whole new places.


The wild cards are always what the solar factors might be, the depths of seismic activity, and the whereabouts of epicentres. Even what I am trying to do is not yet accurate, some have suggested about 75-85% - I am still learning about all it myself, and I am not a qualified seismologist, geologist, nor expert in volcanology. I have no qualification except for being an astrometeorologist, at the very bottom of the feeding chain where it is dark, lonely and gloomy and for which there is no current university chair or course. So anyone who thinks that an unqualified person's comments are irrelevant can easily dispell all of what I am writing here, and simply go and ask their favourite qualified person for information. As I am entirely unfunded, no taxpayer is being short-changed by anything I do or say, so nobody should ever be troubled on that score.  


Possibly significant low tide (high land-tide) times coming for April.

  • 12th:  (neap tide) 3am-5am,  2pm-4.30pm
  • 15th:  5am-8am,  5pm-8pm
  • 18th:  (kingtide) 7am-11am,  8pm-midnight
  • 22nd: (kingtide range) midnight-2am,  11am-2pm   

Always give or take a day. The 5.4 of the 16 April coming into the kingtide range has arguably shown that. The 16th was the day the moon rose above the equator (called lunar equinox). It is of itself a potent earthquake time around the globe.


Of course we hope nothing untoward happens from now forward, and if so that people will remain safe. It is perhaps noteworthy that few seemed fearful on 20 March when a similar maginitude eathquake occuured, presumably because there was enough publicity on the day to make people mentally prepared.


If the reader finds no relevance in all of the above, that there is no pattern, then no harm has been done. If the reader thinks that care might be still taken around certain dates, then the exercise here to examine the patterns has been worthwhile. 



Economic impact

I am very aware that some may take the above times to heart for their own reasons, and that it is irresponsible to predict something that might compromise the economy of Christchurch.
I am conscious that any suggestions of earthquake-risk dates bring huge problems to those in the workforce. But I believe both safety and economy can be accomodated. With mutual negotiation work-absence hours may be managed in a responsible way.
Of course the needs of employers must be considered, for to have all workers down tools for even a few days would bring financial woes for already struggling businesses in the aftermath of what has occurred in recent months.
For those especially concerned for loved ones under stress, taking sick leave that may be due, around risk dates, with the agreement of employers, may be one option for being prepared.
Another may be requesting certain days off, and that time to be made up later as overtime to restore lost hours. In this way ongoing employment is assurred and also peace of mind.
It is also an option for residents of prone areas as defined by Civil Defence and councils, as warned already by seismologists, to just be aware of increased activity zones and times, and extra care being taken then. Evacuation contingencies should be in place anyway, because according to scientists the region will be potentially tectonically active for a while yet.



Warning systems
The best would be via mass text messages on cellphones. It would be cheap and effective. No need for big sirens and hooters mounted on large buldings, which themselves may not stay erect. The boy-racer culture might be consulted on this re-setting up of a database, it appears they may already have done the pioneering. Especially, ironically, around Christchurch. Other warning systems could be a "feed" from the GNS drums directly to emails, such that the public can, by individual choice, receive the same information and at the same time as do Police and Civil Defence.
 Individuals could then relay warnings to their social networks.



Links of possible interest

"The known risk to Christchurch from a tsunami has not changed since the 4 September 2010 and 22 February 2011 earthquakes (Christchurch City Council)"

"If a four-metre-high tsunami smashed into the Christchurch coastline, 23,000 people would have to be evacuated and 8500 homes could be destroyed.."

Unfortunately there is no key as to what the blue shading means.

Watch upper right as the wise cat or dog runs to the middle of the road and stays there.


Little coverage in NZ media: "Phillipines earthquake 6.4 (or 6.9) on 20 March" and
"Volcanic eruption at Indonesia on 19th, Mass evacuation done by govt"




Please note that no earthquake/tsunami predictions have been made on this page, apart from those links quoting from qualified scientists. People seem to want answers and information. Visiting geology Professor Kevin Furlong of Waikato University has said "Healthy debate is very good and not generated by a consensus viewpoint. There hasn't been enough discussion and that is unfortunate."  


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