Hualien-Taidong Leaping Triggered Earthquake Sequence

Just read a paper on the 'Leaping Triggered Earthquake Sequence of 1951' - it's a bit worrying

If the current situation was to follow a similar pattern then we can expect:

1. Two more big quakes in Hualien within the next few days - possibly even bigger than we've so far seen
2. A 6M earthquake around Dong He-Cheng Gong anytime from now to one month's time (it occurred a month later in 1951 but other examples from around the world suggest it can happen much sooner or later as well)
3. A 7+ in Yuli after that
4. A 5-6M near Taidong city after that

The interesting thing is that although all these earthquakes are triggered by the Hualien event, they don't follow a spatial sequence, that is, the second distinct fault line rupture occurred further away from the initial event than the third one. In other words it leapfrogged the closer fault line site

This is explained by the site of the second event having a higher pre-existing background level of seismic activity than the third one

Given the New Year's Day upsurge in activity that we witnessed here occurred roughly between Dulan and Taidong city, then that would make it a prime candidate for the next rupture given it's already shown a high level of background activity

Furthermore, apart from the 1951 event, there was another example in 1986 of a 7M quake in Hualien triggering a similar pattern of events down the east coast

http://web.cc.ntnu.edu.tw/~katepili/papers/Chen_JGR_2008.pdf

So according to the 1951 pattern, there was another 5.8M last night, which could be considered as part of the trio

It's confusing the way they measure the quakes - whereas CWB claimed the previous peak quakes were 5.8 and 6.0, the US seismic bureau measured them as 6.1 and 6.4 - which one is right?

Given the level of damage and CWB's embarrassingly wrong pronouncements so far, I'm going with the US measurement, which would make last night's also a 6.1

That gives us three quakes over 6 - which would match the 3 x 7M of 1951

They are also reporting 94 fore-shocks

Frustratingly, it's very hard to find research papers on foreshocks - they all seem to be about big earthquakes and their aftershocks - which I can't really see the point of

Surely it's far more important to be studying the pattern of fore-shocks - that way you have some hope of working out what's coming instead of endlessly writing papers about the aftermath which are of no use to anyone

This is interesting coz it's the first sign of an earthquake popping up away from the main Hualien cluster, while still following the pattern of the 1951 'leaping triggered sequence' which suggests referred stress will cause an earthquake to occur in the southern portion of the Rift Valley

It was a very minor tremor but worth keeping an eye out for any further activity in that area

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This is really interesting.

I wonder if the professionals sit around and discuss these patterns? I mean, they must, right? Surely there's somebody in a position of authority or at least influence who is connecting the dots.

I wonder if the professionals sit around and discuss these patterns? I mean, they must, right? Surely there's somebody in a position of authority or at least influence who is connecting the dots.

You would think so but jeez, it makes you wonder what the hell is going on there...

In my lifetime I've seen the invention of computers, the internet, seen that huge black and white tv turn to living colour and fit into my pocket, I've seen mind-boggling breakthroughs in space exploration, medicine, weather modelling, etc, etc...

But meanwhile, what have the earthquake academic community and their fifty collective years of public money come up with in the same period of time?

Nothing.

The ability to predict earthquakes now is exactly where it was fifty years ago and there is zero official public guidance regarding the most catastrophic human-impacting natural disasters on the planet

What's up with that?

Exhibit A:

24 hours before the 6.4M earthquake hit Hualien, CWB, under pressure from a jittery public who'd experienced two days of an unprecedented amount of escalating fore-shocks, issued a statement that everything was 'normal', that the peak had been reached ( 5.8M - though US rated 6.1), and there'd be some aftershocks, but relax and carry on

After the 6.4 that caused widespread damage and killed 17 people and injured hundreds CWB issues statement saying 'Whoops! We now think there could be an even bigger earthquake in the Hualien area to follow - actually we don't really know and we're just saying that to cover our arses - but good luck!"

The take-away is there's something radically wrong with the whole academic industry of seismology

Just trying to research it diy style, you'd be amazed how few papers are out there on fore-shocks! Quite common actually in big earthquakes and would seem like a very promising avenue of enquiry if you're in the business of forecasting the big ones

But almost nothing on the subject - instead there are endless regurgitations of studies on big earthquakes, which fault lines they occurred on, how long since the last time that fault failed, how much destruction they caused and lots and lots of stuff on all the aftershocks

Just this apparently is enough to get your grant renewed for another year - though none of it, unfortunately, advances the dial whatsoever on giving the pubic any earthquake fore-warning

All good points.

As I age, I try to be less cynical, more positive, etc., but your observations are beyond debate. So the question is, why is that? Why is there not more of an effort to predict earthquakes?

Is it fear of losing reputation or money? The insurance industry, for real estate anyway, has no stake at all in short-window predictions of a week or two, so they're not going to buy into it.

So it comes down to who stands to profit and who stands to lose from short-term (a few days) predictions of earthquakes GIVEN the reliability of those predictions. If the reliability is low, far more stakeholders (aka big money) stand to lose from low-reliability, short-term predictions of imminent earthquakes. In fact, those same businesses, if they're involved in both commercial real estate and construction, stand to gain from NOT releasing those predictions because not only will they get paid to rebuild, the won't get sued for not evacuating their properties.

And that's the thing. Once the authorities announce a warning, people become liable if they don't take action.

Many stakeholders lose money if the government says, hey, there's a 60% chance of a major quake in the next week here.

So the big money does not want that. The only people it benefits are those living in buildings or structures that may collapse or those planning travel. And the powers that be certainly don't want to interrupt travel, particularly that of tourists.

To play the Devil's advocate, I can see the logic for not announcing warnings that have low reliability, and I think that the low reliability really is the reason behind the radio silence. But, that does not mean there should not be more of a public debate and discussion and sharing of information. There absolutely should be.

I think you're right. And you show that it's a more complex issue that it may first appear

Business owners are not going to stand for losing days of work for an earthquake that may or may not happen

And practically, how would a mass evacuation work anyway - where do you put everyone and for how long and what if nothing happens?

So on the balance of things I can kinda see how it's considered better to just ride it out

Additionally, I also agree that building construction is a key part to earthquake survival though this is a separate issue and there's no reason why earthquake prediction and earthquake-proof construction can't both advance at the same time

However, in the situation we just had in Hualien, there was clearly an abnormal upsurge in earthquakes - in fact it bore all the hallmarks of a so called 'earthquake swarm', as per the much studied 1951 precedent, but CWB went out of it's way to deny this was happening and declared the event finished when it fact it was just warming up.

It's one thing to say nothing but to be announcing everything's fine while the ground is literally still shaking every 30 minutes with 4-5+M quakes is a strange call and makes me highly suspicious

If information is being deliberately withheld from the public then that is a serious matter

Speaking of accurate information, the shock that I reported having popped up away from the main cluster and being a possible sign of a 'triggered leaping sequence' is actually outside of the Rift Valley and not connected to the network of faults that shifted in the 1951 case

"It's one thing to say nothing but to be announcing everything's fine while the ground is literally still shaking every 30 minutes with 4-5+M quakes is a strange call and makes me highly suspicious

If information is being deliberately withheld from the public then that is a serious matter"

Absolutely. There should at least be public debate on it. Why this wasn't prominently discussed in the media is beyond me.

Why this wasn't prominently discussed in the media is beyond me.

Yeah would think even purely out of self interest - for a bit of good ol' fear-mongering media hysteria if nothing else

But within 48 hours it was back to CCTV car accidents and delicious titbits of food from the latest restaurant

Following on from what you wrote originally, perhaps the reasoning goes like this:

1. A major 7-8M earthquake in Taiwan at some point in the relatively near future is a mathematical certainty
2. We don't have a way to short-term predict it with any accuracy and false alarms would create panic, logistical nightmares and cost billions in lost production
3. The most cost-effective and stabilising decision would be to downplay the threat of it - even if that includes the suppression of information

Been doing some reading on 'earthquake swarms'. Don't like the sound of this one:

"In 2013, the Santa Cruz Islands experienced a large earthquake swarm with many magnitude 5 and 6 earthquakes occurring in January and February - foreshocks to the 8.0 2013 Solomon Islands earthquake on February 6."

Ok, thought of a number 4...

4. Given 1-3, it's not in the interests of governments to promote research into predicting earthquakes

...especially if they can't be predicted with total accuracy into a time-frame of a few hours. To get to that level of accuracy, and I assume we will eventually - where earthquakes can be predicted down to the minute - there'll be countdown parties by reckless youths on football ovals - but to get there we naturally have to go through a lot of less perfect levels

Which is not considered desirable coz they will cost a lot of money in lost work-hours, evacuations, and transport disruption as well as cause public panic

That gives you two options - or a combination of the two:

1. Discourage promising lines of research into earthquake prediction

2. Suppress information on partial solutions from becoming public

The thinking could be:

Whether you can predict an earthquake or not, they are going to happen, and cause major destruction. Although not fore-warning will inevitably result in some loss of life, it will also save billions in terms of the disruption costs

Personally, I think the information should be released whether it causes panic or economic loss or not. It's a very slippery slope when you start repressing information that will knowingly result in the loss of life

All good points, and I think they're precisely why they suppress the information. But then, the media does discuss all sorts of doomsday scenarios on the horizon: asteroids, pandemics, and nuclear war. The closest type of event that governments struggle with is volcanic activity, but they're way better at predicting that than earthquakes.

There's been a cluster of large earthquakes in the Mariana Islands very similar to what was going on in Taiwan. This is filtered for 4.5 and above. That blue line to the east of the quakes is the Mariana Trench, the deepest point on earth. We know less about it than we do the Moon.

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Yes, that looks very similar! (I assume there are also associated smaller quakes that don't appear on the graphic)

And close enough to Guam to be causing concern there

I'd never heard of the term 'earthquake swarm' until I started doing some background reading for the Hualien quakes but seems it's not that uncommon

I know about the earth slowing this year - and it definitely feels like there are more earthquakes happening - but actually I don't know for a fact - do you?

If the 6.4 is to be taken as the peak event for the Hualien swarm, there were, according to a table I saw, roughly 100 pre-shocks and 300 aftershocks combining for 400 earthquakes in a 5 day period - that's a helluva a lot of activity

Just checked the Japan mega-quake of March 11, 2011

What I didn't realise was that there were several M6-7 foreshocks in the two days prior to it happening

Seems foreshocks are actually pretty common - even though the myth persists that smaller mid-size quakes are good coz they are 'releasing the build-up of energy' - quite often they are also heralding an even bigger shock to come

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Hope this is not a sign of things to come

Since the Hualien earthquake sequence began, almost all subsequent activity has occurred in a tight cluster around the same area

There was one in Pingdong about a week ago and now one in Taidong near Green Island - but that's it. That in itself is unusual - a normal fortnight in Taiwan you would expect to see small shocks in a range of places across the island

I do expect there to be a significant earthquake triggered somewhere in Taidong as a result of the Hualien failure, and going on past history, we can expect some fore-shocks as a warning salvo. As such, it's a good time to stay alert to the earthquake reports and if a few start popping up in the same vicinity then that would be cause for serious concern

Additionally, it appears a triggered sequence is currently being played out in Mexico - after two big earthquakes from September last year, another 7+ yesterday in a different location

Just to keep an watchful eye on any sign of a triggered event - a 4.4 popped up in virtually the dead-centre of Taiwan - and known home of the 'big ones'

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Not where I thought the next one might be but likely connected to the Hualien event - a 5.3M in Ilan that shook Taipei city - just got off the phone with someone who described it as an 'up and down motion', said she could hear it coming before it hit and that it lasted about 15 seconds

Before CWB put it up, we pegged it as a 5 something in Ilan given that far away quakes usually come through as a wave motion and closer ones are more of a jolting shudder - so we are getting pretty good!

No reports of damage - probably just short of that level and quite deep at 47km

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Hualien-Taidong Leaping Triggered Earthquake Sequence (General)