Nature and Energy of Earthquakes or Seismology for Dummies

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serguei58
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Nature and Energy of Earthquakes or Seismology for Dummies

Post by serguei58 »

We understand that not all geophysicists are on the forum, so we explain "on our fingers" where the energy of earthquakes comes from. We think it will be useful for scientists far from geophysics: https://papers.ssrn.com/sol3/papers.cfm ... id=3498647

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

Post by GuyM »

I've imaged the subducting tectonic plate that eventually pushes under my house. Sometimes that plate gets stuck, until it jumps free. Sometimes hydrothermal fluids in the subducting slab force themselves upwards under pressure. Sometimes there are slow-slip events that reduce the stress. That's all from measurements - onshore and offshore.

I'm pretty comfortable the convergent margin is driving a lot of the activity here, even if my role in this work has been relatively minor.

That said I'm open to new models and ideas if they make useful predictions or forecasts that we can subsequently observe (or use existing data in a blind way); the next big movement on the Hikurangi Margin is of very specific interest due to the associated tsunami risk....

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

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Remember, earthquake prediction is impossible !!!

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

Post by geophix »

serguei58 wrote:
Fri Jan 01, 2021 4:56 pm
Remember, earthquake prediction is impossible !!!
It depends on the definition of prediction. Long term earthquake predictions are apparently much better than short term predictions.

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

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Seismologists, like brave liars, lied, and continue to lie. You want to eat, so they lie! Earthquakes are impossible to predict! And to get a piece of the pie, you just need to declare to the whole earthly world that in 100 years, somewhere there will be an earthquake. This is how everyone can make predictions. No seismologist could predict an earthquake. No one!

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

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serguei58 wrote:
Fri Jan 01, 2021 7:02 pm
Seismologists, like brave liars, lied, and continue to lie. You want to eat, so they lie! Earthquakes are impossible to predict! And to get a piece of the pie, you just need to declare to the whole earthly world that in 100 years, somewhere there will be an earthquake. This is how everyone can make predictions. No seismologist could predict an earthquake. No one!
It sounds like you really hate seismologists. But it looks like USGS agrees with you on earthquake predictions: Neither the USGS nor any other scientists have ever predicted a major earthquake. We do not know how, and we do not expect to know how any time in the foreseeable future. USGS scientists can only calculate the probability that a significant earthquake will occur in a specific area within a certain number of years.
https://www.usgs.gov/faqs/can-you-predi ... e_products

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

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I'm just stating facts. In a private conversation with one great scientist in this field, he literally told me the following: If we admit that earthquakes cannot be predicted, then we will have to resign and admit the fact that we have spent many years on a chimera. Do we need this? No! Therefore, we will tear with our teeth everyone who goes against us.

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

Post by GuyM »

serguei58 wrote:
Fri Jan 01, 2021 4:56 pm
Remember, earthquake prediction is impossible !!!
I don't know any seismologists who claim to be in the quake prediction business; forecasts and models, perhaps, but not predictions. Liej the meteorologists, they choose their words carefully and with good reason - eyes on what happened in Italy.

Wasn't clear to me if you were claiming you had a deterministic model for earthquakes or a stochastic one which is why I mentioned predictions. Either way you'd need to demonstrate that you approaches outperform the current models in a statistically reliable way, and more accurately than current approaches have, when it comes to quale size, depth, location, mechanism and timing.

Again, this is not just academic. Forecast models matter because of the global insurance industry; they need to both reinsure their risk portfolio for earthquakes, and address their immediate liquidity issues (ie having enough $$ to pay out) after a major quake. Forecasting aftershocks are a big part pf this - aftershocks sequences are usually counted as part of the same "event" from an insurance perspective, which places caps on what is paid out.

That has some pretty big implications, and if you do "build a better mousetrap" it makes a big difference socio-economically.

Camping down on the East Coast now. I can see Whakaari/White Island on and off (its a bit cloudy) and further out to the NE lies the Hikauragi Margin, so forecasting is on my mind. So is how long it would take me to reach high ground on foot if there's a big subduction quake.

Unprovable hypotheses come and go; if your models cannot make better forecasts of what might happen, then they might not add much socio-economic value...

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

Post by GuyM »

"If we admit that earthquakes cannot be predicted, then we will have to resign and admit the fact that we have spent many years on a chimera. Do we need this? No! Therefore, we will tear with our teeth everyone who goes against us."

That's not really how science works where I am! You only have to look at the struggles round plate tectonics to see that as soon as the old guard retires or dies, the young guns move in. Science, as they say, advances one retirement at a time.

None of the seismologists I worked with ever talked prediction - especially after events in Italy. And yet there's no end of work and research to do around the whole disaster cascade, forecasting, economics and so on.

Still - best of luck with your ideas - curious to see how your modelling aligns with the earthquake record...

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

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In this article, I tried to present the problem of earthquake prediction from the other side, namely from the side of determining the energy of earthquakes. Only by knowing the source of energy can the mechanism of seismic phenomena be constructed, and knowing the mechanism, it will already be possible to speak about some kind of forecast.

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

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Only by knowing the source of energy can the mechanism of seismic phenomena be constructed, and knowing the mechanism, it will already be possible to speak about some kind of forecast.
I'm not entirely onboard with that. Mostly its the other way round - we develop some form of empirically-derived model that makes useful forecasts and then try to dig deeper into the mechanism. Gravity for example - which we cheerfully use in geophysics.

Actually an awful lot of geophysics is the other way round - we make measurements/observations and then invert those to try to image/understand what is going on. Either way, if you do have a new mechanism it needs to be able to completely explain all of the phenomena that have been observed and recorded to date, including waveform shapes and travel times, as a minimum threshold.

So - more work to do, I think.

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

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I disagree with you. Building a model requires an energy foundation. Otherwise, we will build a model with unclear parameters and capabilities. That is, we will fantasize without any reference to reality. Take gravity. Why can't we master this physical strength yet? Because we do not know its mechanism and energy source. We try to build a model, but we fail. And it will not work until we find a source of energy for the force of gravity. So - more work to do, I think.

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

Post by GuyM »

Fully agree we haven't mastered gravity because we don't understand it; the models we have still allow us to make extensive use of gravity in exploration, whether that's sub-surface, remote sensing via satellite or sending probes to the far reaches of the solar system. In that sense the predictive models we use are not failing - they are pretty useful approximations.

I guess the key question is what measurements are you making that the current seismological models fail to agree with?

Or alternatively can you explain how your model for earthquake generation would apply to the subduction zone along the Hikaurangi margin, from the point of view of predicting the earthquake mechanisms in a way that would support better early warning of tsunamis in that region?

I know I keep on coming back to measurements, but ultimately for me that's the foundation of geophysics, and broadly why I chose to specialize in geophysics rather than the abstract world of the theoretical physics.

Still - if you want to challenge the status quo, the burden of proof falls on you. It's not down to others to defend their work, it's up to you to find physical supporting evidence for your model - just as it was when plate tectonics was the key revolution in geophysics.

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

Post by serguei58 »

GuyM wrote:
Sat Jan 09, 2021 10:09 pm

Still - if you want to challenge the status quo, the burden of proof falls on you. It's not down to others to defend their work, it's up to you to find physical supporting evidence for your model - just as it was when plate tectonics was the key revolution in geophysics.
Of course, no one will prove for me the provisions stated in my work. This is what I am doing. Thanks to everyone who helps me.

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

Post by GuyM »

To me that's the yardstick for any new theoretical or modelling approach - the modelled results from that approach have a better (statistical) fit with the observations we make. Without that you don't have a hypothesis that is falsifiable or indeed that can be tested.

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

Post by Akusta »

a href="http://www.ca.sandia.gov/casite/gupta/r ... 1974">This paper</a> says the 1974 test was 4.9 on the Richter scale.

No mention of mb values.

I wonder whether the monitoring regime was geared up with all their monitoring staions and magic formulae in 1974? I think not.

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

Post by serguei58 »

Akusta wrote:
Wed Jan 13, 2021 2:55 am
a href="http://www.ca.sandia.gov/casite/gupta/r ... 1974">This paper</a> says the 1974 test was 4.9 on the Richter scale.
Can't access the specified site

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Re: Nature and Energy of Earthquakes or Seismology for Dummies

Post by serguei58 »

As you can judge from the material presented in the article, geophysicists made a big mistake in accepting Mr. Reid's hypothesis as the only light in the window.

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