Predicting earthquakes: Ring hedges his bets

Below, University of Waikato biological sciences lecturer and Science Media Centre Sciblogs contributor Dr Alison Campbell responds to "Moon Man" Ken Ring's recent prediction that there will be another Christchurch quake on March 20.

Fellow SciBloggers Peter Griffin and David Winter have recently written posts on Ken Ring’s (in)ability to predict earthquakes (here and here).

This is something I’ve also touched on earlier and I thought I would follow up on it now – the specific issue I want to address is that of hedging one’s bets.

Last year Ken wrote about the possibility of a ‘moonshot’ affecting New Zealand – a major earthquake triggered (he believes) by the close approach of the moon. (As David’s already pointed out, there appears to be no such causal link.) When I asked him about this on my own blog he seemed to pull back from his initial statement, saying instead (here in the comments thread) that:

As to the 20 March, the “one for the history books” comment came from an interview with Marcus Lush. I was just agreeing with him to be obliging. I do not hold that 20 March WILL bring a severe earthquake to Canterbury, but an extreme weather event is possible that day worldwide, and an earthquake within 500kms of the Alpine Fault is a risk on that date. More likely to be a 4-6mag.

In this comment he appears to be pulling back from his original statement (and being a little disingenuous – the “one for the history books” comment was also made on the Silly Beliefs blog, for example).

He’s also hedging his bets – the phrasing here is so vague that just about any untoward event would count as an accurate prediction. Just what would qualify as a “severe weather event”? Will it really be “worldwide” – as in the sense of “global” – or is this statement intentionally broad so that any instance of severe weather on March 20th, anywhere in the world, could thus count as a ‘correct’ prediction? (What is “severe”, anyway?) I have asked Ken for clarification on this, on the SciBlogs mirror of my blog, but so far – despite him saying there that “I never shy away from questions” – I’m afraid I’ve had no further clarification.

Imprecision
The same imprecision is present in the statement about the risk of an earthquake “within 500kms of the Alpine Fault”. 

Assuming we’re talking about 500km radius (again, I’ve had no clarification from the author of this statement) – well, heck, that’s a huge area: all of the South Island and a fair bit of the North as well. And we have earthquakes all the time in New Zealand – the country’s not called ‘the shaky isles’ for nothing! So again, this simply cannot count as a prediction; it’s simply stating the obvious. (And in a recent post on his blog, Ken has said that the Alpine Fault itself seems to be fairly inactive at the moment. However, as we have said, it could be anywhere in NZ, or it may not even happen at all. Again, this is extremely vague and effectively covers all possible options.)

Inconsistencies
There are other inconsistencies in Ken’s various postings. For example, on October 13th he’s on record as saying that it was unusual to have one large quake followed by another in the same area, so that there was probably little risk of another large earthquake following the September 4 event. More recently, with his claims to have predicted the terrible event of a week ago, he seems to have reversed this position.

Leaving aside the accuracy of that claim, there are other questions that I would like to see answered. (After all, when scientists change their minds they are up-front about the reasons for doing so.)

Moon still in its usual place
And as you might expect, my questions relate to evidence: what’s changed, between those two oh-so-different predictions? Ken Ring claims that his ‘predictions’ are based on his reading of the position and movement of the Moon, planets, and stars (on astrology, in other words – his characterisation of the Moon as a planet would bear this out).

But the Moon is still in its usual place, the planets haven’t changed their courses, and if the stars do move it’s going to be a very long time indeed before we know anything about it. So what was the basis for his reversal of opinion? I’ve asked, but to date I’ve had no answer.

Vague
Various commenters - on SciBlogs pages, Silly Beliefs, the comments relating to the now infamous February 28 Campbell Live interview, and elsewhere – have said that in their opinion Ken Ring’s ‘predictions’ are accurate; they’ve seen them come true. 

The problem is though, that such vaguely worded ‘predictions’, with their lack of precision, are so wide open that they lend themselves to confirmation bias. Something happens, and if it falls within the wide boundaries of a particular claim, then there’ll be a tendency to regard that claim as having been accurate.

Waiting for March 20
So what’s it to be, on the 20th March? 

A quake in the South Island – which given the dreadfully high frequency of aftershocks from the latest event is effectively a given, or somewhere else in NZ?

Somewhere in the ‘Ring of Fire’ that runs along the boundaries of the Pacific tectonic plate? (This is not an idle question – Ken has said that the 7+ [which he was 'predicting' for February] is sure to be somewhere in the “Ring of Fire”, where 80% of all major earthquakes seem to occur, and NZ is at the lower left of this Ring. There are earthquakes along that plate boundary all the time, so any event would have been viewed as a successful ‘hit’.)

A worldwide ’severe weather event’, or maybe a ’severe weather event’ somewhere in the world.

Take your pick.

But please don’t tell me that such ‘predictions’ could be construed as accurate.

This content is syndicated, via The Science Media Centre's Sciblogs from the University of Waikato's Bioblog.