Finally media awareness of Auckland volcanic threat

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This is the third time we have written about the threat posed by a volcanic eruption in the Auckland Volcanic Field, that underpins much of Auckland City, New Zealand. We first wrote about it in March 2013, then again in April 2013, and again in this article. Finally, today, the NZ Herald has decided to write about the issue, which is critical, not just to alert people, but for government to actually take steps to avert castastrophe. What people need to consider is:
1. There is no reason not to expect another eruption. They have been so periodic that it gives high causal justification to expect another at some point.
2. Volcanic eruptions when they underlie or adjoin a city pose a huge disruptive force; far more catastrophic than earthquakes.

The reason why this is so is because:
1. The sonic blast from the volcano is going to shower the city, or parts of the city with rock debris, killing people, destroying a lot of popular. The impact would be akin to an earthquake. Less damage to the structural integrity of buildings, but more damage to their cladding/facade.
2. The volcaniclastic material and dust will blanket the city. The implication is that it will be a huge disruption to the city. Compared to an earthquake, where the people can get on with their lives within a week, i.e. Businesses can keep going, if they are psychologically prepared, and where there is relatively less disruption to transport, and only 'certain zones' are affected. Widespread dust will stop everything. Its akin to a snow storm; and even if you move the dust, it will wash back with rain. It will be redistributed by train. In contrast, an earthquake spreads no debris, aside from liquefaction (sand) along fault lines, and often it does not even rupture land/highways, so its simply undermining buildings/foundations in certain zones. It was rather unlucky that the central CBD of Christchurch was even hit. The other issue was the 'shallowness' and 'intensity' of the quake, and the fact that Christchurch was not designed for such events. i.e. It had many relict 'brittle' structures. In contrast, Japanese earthquakes are 80-100km deep, the earth 'rolls' and buildings sway accordingly.

Now, the good news is that it might not be central to Auckland, but rather on the fringes, so having less effect, and possibly not blocking major transport corridors. It might be a relatively small eruption with insubstantial dust. The win has a good chance of carrying the dust out to see, and strong wins will serve to disperse the dust further afield...though for a major eruption, that could actually be a problem. A greater problem is perhaps that there is no precedent for this event. It has no modern comparison. It will be not as severe as the Pompeii (Italy 11th Century?) or the Mt Pinotubo eruption in 1984 (with its 11 feet of ash). These are different styles of eruption. So, we are really in the dark as to the precise nature, however much can be garnered from exposed ash deposits. After all, that's how they are able to calculate the historical significance of these fields. NZ is one of the few countries to build a city on a volcanic field. I'm not aware of any other, aside from Iceland, where the entire island is a volcano. Even then, its not so much an explosive style of eruptive volcano, but generally a non-viscosity, fission-style type of eruption.

Now, in commercial terms, you generally build infrastructure with a 20-40 year life. So it might make sense to build a city on a volcanic field. Sadly, that concession only works if the eruption is after your 40 year project life. You might otherwise feel a bit jaded if you did not take a threat to your property seriously if you'd just made improvements to your property and then an eruption occurred weeks or a year later...even 5 years. The reality however that, its not so much a problem of infrastructure loss as:
1. Looting and vandalism in the wake of it, as you flee for safety
2. Destruction of gardens, external façade, windows
3. Damage to internal windows. Recognise that there will probably not be materials to board up your house windows, if that will even make a difference. It will depend on the size of the blast and your proximity to an unknown centre within the field, or close to it.

It becomes apparent that Auckland will be disrupted for several months. Food will need to be flown in until arteries are cleared. Rain will play havoc with that. It will be a different, even unique type of emergency.

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Auckland - live in fear - Rangitoto volcanic eruption

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Popular wisdom is that the two recent volcanic eruptions that struck Auckland, NZ's largest city are nothing to fear. I would care to differ for two reasons:
1. You cannot trust governments to tell you anything or to identify and act on any substantive evidence. Recent examples include the Christchurch earthquake, where a city engineer who warned about the risks of an earthquake was ignored.
2. The other example being the Tohoku tsunami where the people were lied to about the details of the risks posed by nuclear meltdown.

There are some 49 volcanic centres in close proximity to Greater Auckland City. If you want to get a sense of just how close those volcanoes are - you need only look at the maps in the following city report. Remember however subsequent eruptions will unlikely be associated with prior structures. They do however occur in clusters, and Greater Auckland City is a 'cluster'.

The fact that there were two earthquakes in Auckland is not important. They were closely related spatially and chronologically, so they could be considered as giving stress relief to different parts of the lithologic units. What is important is the shallow depth; the lack of alternate explanation, and the nature of Auckland's style of volcanism. By no means is Auckland's style of volcanism particularly severe, but consider that:
1. Volcanism is a threat under-estimated by people. Even a small eruption in the vicinity of a major city is going to be very serious. Far more serious than the Christchurch earthquake.
2. This style of volcanism occurs without warning - hourse compared to months for a volcanic arc eruption

Maori folk stories spoke of historic volcanic eruptions. The difference is that Maoris had no infrastructure to be destroyed, nor did they themselves have much exposure to these events, as they themselves have been in NZ for just a short time, so the land was relatively unpopulated. So what do we need to know about this form of volcanism:
1. Earthquakes can result from tensional release, i.e. Redistribution of lateral stresses
2. Inflation of volcanic plume or their deflation, i.e. Vertical stresses
3. Hydrostatic loading or unloading, i.e. The filling of a dam or its water loss in drought

Auckland is not on a major global fault. It is possible that residual stresses from movements on those faults is causing secondary earthquakes around local volcanies. There is the possibility that the drought has reduced vertical hydrostatic loading around Auckland, and this has caused earthquakes. My personal opinion is that this is not likely the case because there don't appear to be any large water storages around Auckland. I went looking but the information is not readily available.

This style of volcanism is well-documented for Auckland by GNS (Geological NZ Survey). These eruptions start with melting in the upper crust as a result of hot spot magma intrusion. Partial melting in the upper crust will result in the creation of a plume at depths. The heat from the plume will effectively drill its way through the crust until such a time as the plume is able to take advantage of its inherent force, i.e. when the magmatic pressure equals the load pressure. i.e. The plume will reach a level in the crust where it will be able to intrude a long structural weaknesses. GNS says that once a line of weakness is developed, these fluid magmas can rise at a rate of 5kms per hour. This seems hard to believe (even for me), but don't under-estimate the explosivity of these eruptions. The other problem is just how undocumented these eruptions are. You might expect some type of sonic blast when they occur, and the formation of a crater. As the blast pressure wave reaches the surface there will be a lateral blast as the force blows out material. This is because from about 300-500 metres depth the confining pressure will drop off immensely, so any near-surface planes of weakness will be exploited. This makes the earthquake more dangerous to you. This is particular so if you live in a house with a lot of glass windows. Expect them to be shattered.

What are the risks according to the government?

They list them as "ash falls, ballistic rock falls, cone-sector collapse, pyroclastic flows and surges, debris flows, lava flows and domes, lahars, volcanic gases, volcanic earthquakes, tsunami and seiches, hydrothermal blasts, and atmospheric effects. Many of these phenomena will only affect an area on the volcano or a few kilometres from the volcano. However, volcanic ash fall can be deposited hundreds to thousands of kilometres from its source, making it the product most likely to affect the largest area and greatest number of people. Volcanic ash can seriously affect aircraft that may fly unintentionally through the ash cloud, often many kilometres from the volcano".

The good news is that these earthquakes might not be signalling an eruption. i.e. The earthquakes might in fact be signalling a deflation of the volcanic hot spot. There is however no reason to expect this, and more reason to expect any waning of activity to be associated with stress release. Where was that release? Only unloading from surface reservoirs. This seems unlikely. Another big issue for Auckland is the location of these earthquakes. The last recorded earthquake in NZ was 600 years ago. This centre actually erupted twice - its on Rangitoto Island, offshore from Auckland City. That is scary because it establishes a geospatial link to past volcanism. If you look at the ages of volcanic activity on Figure 2 its apparent that these earthquakes are associated with the general area of the last eruption. We need to consider that Waitemata Harbour might be concealing a history of volcanism that we don't know about. Importantly, the proximity of the harbour poses the risk of a mini-tsunami for Auckland's North Shore and city coastline.

I went looking for heat flow data which might suggest that there is no 'immediate' heat event. But actually there is compelling evidence that the intensity of volcanic activity is increasing - read the quote below. This might relate to the fact that volcanism is offshore, in the process resulting in sub-surface mixing of seawater and magma, resulting in greater eruption explosivity.

"The area covered by each volcanic centre is generally localised (less than a kilometre across) and the total volume of erupted material is small. However, five of the volcanoes (Mt Mangere, One Tree Hill, Three Kings, Mt Eden and Mt Wellington) are of medium size. The largest, Rangitoto, is an exceptionally large volcano for the field, representing 59% of the total volume of erupted material. It is significant that the five medium-sized eruptions occurred between 20,000 to 10,000 years ago and that the largest eruption was only about 600 years ago". 

So the latest recorded volcanic eruption from NZ was the most explosive. I suggest because it was offshore, but it might also point to an escalation of heat. This is not to say that the eruption is imminent but that it is probably a risky decision to live in Auckland; most particularly the North Shore and Waitamata Harbour side. A cluster of volcanic earthquakes is clearly a sign of greater volcanic intensity given the relatively active nature of the Auckland field. I say people - be careful. Governments will minimalise the risk because they will want to preserve economic activity. They will not want to displace a million people. Personally, I'd be crying out for heat flow data which I can't find online, and I'd be really keen to watch future earthquake activity around Auckland City...particularly I'd be interested in the location of that activity, whether it was around Rangitoto Island, or whether its associated with faults in that area. The drought might actually be accentuating  the risk by 'unloading' confining pressure, but I'm inclined to think not given the high rainfall of Auckland, the small size of the city, and the fact that I can not locate the reservoirs. Surface storages and even the confining pressure of the crust are relatively weak counterforces in geology. I remind you to not under-estimate the force of the earth's mantle. The thickness of the crust is just 30km; the interior is 6400 kms in radius. That thin crust gets a bit precarious when molten magma 1300 deg C has already reached 5km depth and is seeking structural weaknesses to make its way to the surface.

There might be a reason there is no 'oral record' left by Maori. It might be because they were all killed by these eruptions. No written records is another explanation, and possibly the low population of the region. In any respect, you have the good fortune of more forewarning....but I caution you...more information is required on heat flow...and if you don't have the discretion to leave Auckland, then you might want more seismic/earthquake evidence. Read the following report to better understand what you are dealing with. Don't trust your government!! Well, you might watch to see if your local MP is spending less time in your (Auckland) electorate. Actually, no, just don't trust their faith. Follow the evidence...like the people of Christchurch didn't. Remember volcanoes can be more dangerous in many respects than earthquakes. They are different. Read this report to better understand the nature of what you are dealing with. Australia just started looking a little better. Here is a little history on Rangitoto Island - but no heat flow data!!!!!! Here is another warning from 'volcano watchers':

"Future vent forming eruptions will very likely occur within the city limits or its outskirts, allowing few mitigation or preparation options. Scientists agreed that residents of Auckland may get only a day or two warning of a volcanic eruption and will only know hours before where it will explode on the surface".

Was yesterday's earthquake a warning? Yes and no. We are looking for a pattern of earthquake activity. We already have a geospatial point of correlation. The question is what is the cause? Inflation or deflation. Heat flow will tell us. Is government keeping this information from us? Interestingly, if you look at this map of NZ, it is evident that NZ has a 'dog leg' in its stress relief. This is an interesting issue which might foretell future tectonism. Tension 'gashes' or faults might be opening up which are facilitating the higher degree of volcanism we are seeing. Remember that the subduction to the east is already creating an area of high heat flow (resulting from deep-seated melting) and lithospheric bending (brittle fracture) along this purple line of weakness. Is there going to be a change in regional tectonism. These developments will take millions of years. But the opening up of tectonic 'gashes' might well be imminent.

Here is a very realistic description of the threat posed by a volcano eruption in Auckland. It gives you a clue as to what you can do in the case of an earthquake. The threat is broadly greater if you are detached from your kids because they are subject to others guardianship at school. Yes, bureaucrats who need to follow government rules. So what do you do:
1. Get to a concrete building (preferably having already identified a 'sponsor' or a few in case of non-availability). Avoid any room where there is windows as there is going to be a 'sonic' or basal blast of volcaniclastic material.
2. Avoid near-shore environments. If near Waitamata Harbour, a likely epicentre, ensure you rise to a 3-4th floor in the concrete apartment so that you will not be swamped in any mini-tsunami.
You will want these places to be within a few blocks of your home. Identify them at home and at work. Toilets are great because they are small rooms with small windows. If in glazed rooms, you will need to wrap yourself in towels, or hang towels over the window might help.
How will you know to do this? Personally; I have no idea. Good to do around the time of an earthquake, but you might not even feel it. Worst still you might not see anything (at night) until the incident has passed. You are most likely going to be killed by the basal surge shattering all the glass windows in your building. You might want to pre-order your glazing and store the glass in the basement. There might be a supply shortage in future. The other problem is food & water, but these are lesser problems because the dust is readily cleared and the infrastructure is hardly going to be damaged. Its a risk of people losing lots of blood from being punctuated by a lot of glass.

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Author Andrew Sheldon| Applied Critical Thinking | www.SheldonThinks.com

New Zealanders taking permanent leave

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As expected New Zealanders are leaving the country in droves and immigrants and tourists are tending to stay away as well. Most of those leaving are probably salary-earners rather than small business owners, who will tend to profit from the reconstruction. The following article suggests that middle income earners have been particularly hard hit by higher taxes. i.e. the tax system in most countries is so skewed against the salaryman, that people are inclined to seek out any concession, rather than doing what they should do, and stop sanctioning a terrible form of government 'democracy' and the right of government - or that blessed 'majority' - if ever there was one. Stop sanctioning the right of the minority to extort from another minority. That is not the genius of democracy; that is what makes democracy just a legitimatised form of tyranny like the ones of old. This might strike you as strange but that legitimacy comes in the form of your right to vote. Yes, voting. The right to a meaningless sanctioning of a person you have never met, to execute policies you don't know, who purportedly competes against a party who is very much the same, engaged in the same form of extortion, to stay in power. Allies I'd say more than competitors. But by all means, go to Australia, and win the right to be screwed by a different democratic franchise. You will end up becoming a repressed materialist like all the other Australians. If depressed; go shopping; and give the government more points for stimulating economic activity...as opposed to productivity..which is what really counts. That's right, we do not even measure government by the right tools....anyway they control all the data.

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Author Andrew Sheldon| Applied Critical Thinking | www.SheldonThinks.com

Life in the wake of the Christchurch earthquakes

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NZ will have to change the way it thinks about life. Most people tend to take life each day at a time. We can't afford to do that......at least not after one confronts the urgencies of the tragedy and trauma. The deaths and injuries in Christchurch to date were because we hold ideas in disdain for the 'practicalities' of the moment. People with ideas warned government officials that there were risks, and they were ignored. Never expect government officers to be champions for ideas. They are middlemen who deal in concrete matters because their lives are driven by perceptions, which tend to evolve around facts because that is all that most people consider.

We need to think conceptually, which means analytically, critically and long term. It is what distinguishes us from animals which function on the basis of mere correlation. Our capacity to appreciation or 'understand' causation is the capacity which allows us to see around corners. Japan only sparingly learned the lesson because of its far greater exposure to earthquakes. It shows that earthquakes are not particularly dangerous if we anticipate them, plan for them, and build for them. The buildings in Japan shake like trees and yet they preserve their structural integrity. Those buildings and the people who occupy them go about their lives knowing that they are safe in the knowledge of technological progress.

Japan suffered from the tsunami because of its compartmentalised thinking. It shows that people might live under the illusion that they are prepared, but its merely accepting the reassurances of 'short-range' government bureaucrats. Only one of the mayors in the NE of Honshu had made adequate provisions for tsunamis. His provisional construction efforts, which entailed building a number of concrete sea walls, spared the lives of his electorate. He is a rare thinker who challenged popular consensus. Such thinking is all too rare because it is not supported or affirmed by our political system. On the contrary, our political system advances perceptions or concrete facts as the basis for decision-making. I don't think you can fully comprehend the damage this has done to society, and what it will do to Western democracy in the future.

I will say more on this issue, but I will save it for forthcoming books.

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Author Andrew Sheldon| Applied Critical Thinking | www.SheldonThinks.com

Implications of the Christchurch Earthquake to NZD

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The cost of the earthquake is believed to be around $16 billion. The hit to the city is going to cause many people to leave. They can be expected to take their insurance payout and go to Australia. Expect about $3 billion of insurance funds plus another $1 billion in savings to go to Australia in the next 2 years. In fact some will stay here, maybe going to Auckland, if only because of the hit on the NZD will make Australian out-of-reach.

The bad news of course is that there is potentially more earthquakes to come. Escaping Christchurch might not be the solution either. The stresses being released along the Tasman Transform Fault might well shift to the North Island. Already there was a 4.5 magnitude earthquake in the Kapiti region. Of course escaping the plains and high-rise buildings offers some reprieve, so does avoiding brick (brittle) structures, or new earthquake-proof designs.

On a more positive note, Christchurch presents a fresh-faced investment to build a new city with a new image. That might take time, but it will also create new jobs, and imagine that a lot of businesses will be opening to replace those lost. Its a fresh canvas. The opportunity is also a huge risk if it lacks taste.

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Author Andrew Sheldon| Applied Critical Thinking | www.SheldonThinks.com

Photos of Christchurch at its best and worst

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Interested in seeing some photos of the Christchurch historic buildings before and after; take a look at these photos. It must be acknowledged that these buildings appear to be only superficially damaged. The problem is the structural integrity might be compromised. It was a very shallow earthquake, only 10km from the city centre. It could not have been much worse because the earthquake occurred during the day, so there is probably 300-odd people dead. It would have been worse perhaps if it was not lunchtime. If it was nighttime, maybe only 30 people would have been killed. It was very unlikely to have a direct hit on the city centre like this. It is unlikely to get any worse....unless Wellington is next. That would be truly dire....though I would not miss the destruction of the NZ parliamentary building...preferably when it is sitting. Sadly, NZ has not been been having much luck lately.

Anyone retaining some sense of loyalty to their political masters ought to reflect on:

1. Their lack of accountability

2. Their capacity to extort wealth from people

3. Their lack of principles

4. Their lack of honesty

I must say, I am far more impressed by leaders in local government. The mayor of Christchurch does a far better job. Might that be because local government leaders are less able to side-step issues; or maybe its because people are not forced to 'choose', so each vote becomes more real. Or maybe its because their taxing powers are much more restricted. In any respect, its not a desirable system....and a spin off from the main game. Want a conception for a better NZ - consider this blog.

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Author Andrew Sheldon| Applied Critical Thinking | www.SheldonThinks.com

NZ needs new centres of growth

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Following the earthquake, in an interview with John Campbell, Mark Quigley, GNS spokesperson, made a very public and political solicitation for funds for research. He said this is 'fundamental science', actually it is applied science, and I'm not even sure it would have helped. The reality is that the GNS might never have an accurate model for the sub-surface. I suspect for it to develop an accurate model, it would need to drill a great number of holes several kilometres into the earth to place sensors in the ground to measure movement at different places. This does not seem feasible - principally for the fact that the 'active' geological terrain in question might comprise a great many slivers of crust with a succession of faults absorbing or releasing the stresses, so picking when and where the stresses are going to be released does not strike me as easy science.

Although it may well be sensible to increase the budget for GNS, I actually think the government needs to do some other things, including adoption of the following policies:

1. Ensure all new construction in Christchurch is earthquake-resistant. I have no idea whether the existing standards are adequate. Probably they are, and if not, then the assistance of the Japanese will probably help.

2. Adopt a 'slow-growth' model for Christchurch

3. Adopt measures to diversify NZ's population away from Christchurch by moving government jobs. The reason for this is that Christchurch might well be passing through a 300 year period of 'geological activism'. You do not want your 2nd largest, fastest growth city exposed to such destructive potential. Decentralising government jobs is the best way to create new cities. Oh course there is too much investment in Christchurch to abandon it, but this ought to be a long term strategy.

4. Develop new cities around existing infrastructure in Invercargill and somewhere like Motoeku (near Nelson). Of course port facilities will be critical to such a city. The South of the South Island already needs a new airport to handle tourism I believe. Queenstown is 6 hours from Christchurch, and its a hub for international tourism. There is a need for a larger regional international airport to service Dunedin, Invercargill, Queenstown and Wanaka. This is a good way of kickstarting such decentralisation.

NZ needs to think about whether it should rebuild Christchurch or scale back. Of course, NZ is not the only country to have earthquakes. San Francisco is built on the San Andreas Fault. Japan is subject to faulting, etc.

The difference is that Japan is pretty unstable regardless; and Tokyo was already well constructed, since it experienced a bad earthquake - the Great Kanto Earthquake - many years ago (1923). The difference is that Christchurch has a choice. There are areas in NZ which are a lot more stable than others, and diversification makes sense. Its not a divestment, but a shift in priorities and focus. The same can be said of Wellington. But that is a 'bureaucrat city', so its prone to gentrify anyway. Governments are naturally very good at killing things.

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Author Andrew Sheldon| Applied Critical Thinking | www.SheldonThinks.com

Christchurch in crisis - 2nd earthquake

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Christchurch is currently the scene of a crisis. The GNS are trying to forcecast the next earthquakes and where. I would suggest that is optimistic. Geological processes on Earth have been acting for billions of years. Modern Man has been occupying this planet and recording these events for just 3000 years. Even then the quality of the seismic record is just 100 years old. They are forecasting in the dark. NZ has only been settled by Europeans for 200 years.

NZ's South Island lies on a strike-slip fault when extends right along the island. There will be ongoing releases of stress along that structure, which is not a single fault, but a system of parallel and sub-parallel structures, each with their own stress characteristics.

Earthquakes are of course brittle (shallow) or semi-ductile (deeper) releases of those cumulative stresses. The most exposed or vulnerable areas are those areas on deep sedimentary piles, because they will oscillate when the earthquake hits. Clearly a major stress release carries the prospect of ancillary stress, or may even facilitate ongoing primary stress release. There is no way of knowing given that the stresses would need to be measured under the sedimentary pile.

Many people are disillusioned with the uncertainty of living in Christchurch. The future of the city is in jeopardy. Life in NZ is already difficult with the recession and lack of business investment. It does not help that the only investment is replacing the capital investment destroyed. Other parts of the country will also feel the implications. The bad news is:

1. The loss of business as a result of the clean up and restoration of services

2. Loss of tourism as the prospect of more earthquakes remains

3. Loss of students who decide not to continue their education in NZ, and instead go to Australia, i.e. 23 Japanese students are currently still trapped in their school (I believe??)

4. Many of Christchurch's residents will leave the city. I suspect many of them will go to Australia for higher earnings, and to escape the threat. Australia seldom experiences earthquakes. Its a very large, stable continental craton. Having said that the Newcastle earthquake 15 years ago did a lot of damage. The threats there are around Camden (NSW) and Kalgoorlie (WA). So a small prospect of threat for such a large country, and the threat is subdued. NZ'ers leaving will have flow-on effects for the country. The destruction of come of Christchurch's oldest historic buildings is very sad.

The only good news is the hit to the NZD. NZ exports 95% of its commodity production, so this spells stronger capital inflows for the city. There has been thousands of after-shocks since the initial earthquake in Sept 2010. This one is not as strong as the last, but it struck the centre of the city. It has destabilised a lot of buildings.

The bad news is that the geological stresses released along the fault zone will create new stresses along the fault zone. The good news is that there are no other large cities on the Canterbury Plain....that is good news. You might not extent more bad news. I think this is as bad as it will get. After tremours will likely be in different areas, i.e. in the suburbs. The problem is the weakening of already weakened structures. So there will need to be a lot of demolition.

The other great risk for NZ is the threat of an earthquake in Wellington, which is far along the same fault system. Wellington is not as vulnerable though because its sedimentary pile is very shallow; or non-existent, since many people are living on bedrock (i.e. hill sides). The greater threat is earth slips in the case of Wellington, whereas in Christchurch it was the tremours and liquefaction of the unconsolidated, saturated sediments near the surface.

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Author Andrew Sheldon| Applied Critical Thinking | www.SheldonThinks.com

Earthquake today

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We had an earthquake in NZ today. It felt like about 4 on the Richter Scale. Nothing really. I shudder more than that when I've had a few NZ beers. It occurred for about 2 seconds. We get to experience similar strength earthquakes about 4 times a year I guess.
There is really no comparison to Japan when it comes to seismic intensity. Based on similar frequency, I'd expect to experience a few 'heaves' and 'rolling' motions. Tokyo is the worst because of its position on a large sedimentary plain which exacerbates the intensity of earthquakes. Earthquakes there tend to persist far longer as well. Over 30 seconds is common, and often there are several together.