Talk:Counterexamples to an Old Earth

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Major earthquakes are doubling every 40 years?

This claim should come out because it's false. Proof that it's false can be found here:[1]. For example between 1900 and 1909 there were 120 major earthquakes; between 2000 and 2009 there were 99. 100 years and no doubling - in fact, a 20% decrease. It doesn't help our case to make arguments that can be demonstrated to be false in 5 minutes. --MandyC 18:57, 23 October 2011 (EDT)

That database appears to depend in part on the amount of property damage, which would distort the results beyond recognition.

Large earthquakes increased by 20% over the past decade, which fits almost perfectly the estimate of doubling every 40 years.--Andy Schlafly 19:03, 23 October 2011 (EDT)

They've doubled every 40 years if you only go back 40 years. If you go back 110 years they've stayed constant or decreased slightly. That database includes ALL major earthquakes; property damage is just one of the criteria you can search on. --MandyC 19:10, 23 October 2011 (EDT)

Actually I'm wrong. They've increased by 80% in the last 30 years. They've only increased by 20% in the last 40 years. They've stayed constant over the last 110 years. Numbers fluctuate but is always about 100, +/-30, per decade. There is NO INCREASE in major earthquakes and we shouldn't be claiming there is, because we can easily be proven wrong. --MandyC 19:14, 23 October 2011 (EDT)

The table in the cited reference shows an increase factor of 1.5-4 every 38 years, and recent trends confirm a substantial increase over the past few decades. The statement seems well-supported by the table and recent data.--Andy Schlafly 19:56, 23 October 2011 (EDT)

Yes, but the cited reference contradicts its own cited reference, which is the USGS earthquake data (found in the NOAA database.) There has been a substantial increase per decade since 1980, a MINOR increase per decade since 1970 and no increase whatsoever since 1900. The 1970s had exceptionally low earthquake activity and the increase since then is a statistical phenomena known as regression to the mean; it's the same numbers trick that makes it appear that speed cameras placed at accident blackspots reduce accidents. Anyone can cherry-pick figures to prove anything, but the long-term increase simply isn't there. There were more severe earthquakes between 1900 and 1910 than between 2000 and 2010. --MandyC 20:13, 23 October 2011 (EDT)

Today the study Global risk of big earthquakes has not recently increased was published: the authors show that the earthquakes of the last hundred years fit well into the model of a homogeneous Poisson process, i.e., there is no increase of the number of big quakes. Together these facts suggest that the global risk of large earthquakes is no higher today than it has been in the past. AugustO 17:50, 20 December 2011 (EST)

AugustO pulls out the heavy artillery: The Poisson distribution! The material on multiple regression and the Poisson distribution were my favorite parts of the last statistics course I took. :) Conservative 22:08, 20 December 2011 (EST)

AugustO, the article states, "The global rate of M≥8 earthquakes has been at a record high roughly since 2004." Its conclusion that earthquakes have not been increasing based on its view that "no plausible physical mechanism predicts real changes in the underlying global rate of large events." They need to spend more time studying and learning from Counterexamples to an Old Earth. Of course there is a plausible mechanism: increased disorder affects the Earth just as it affects everything else.--Andy Schlafly 00:08, 21 December 2011 (EST)

Mr. Schlafly (Andy? What's the etiquette when user name = real name?), respectfully, I believe your short quotations from the abstract of the paper distort the context in which they were made. Here's the surrounding context:

“

We examine the timing of large (magnitude M ≥ 7) earthquakes from 1900 to the present, after removing local clustering related to aftershocks The global rate of M ≥ 8 earthquakes has been at a record high roughly since 2004, but rates have been almost as high before, and the rate of smaller earthquakes is close to its historical average. Some features of the global catalog are improbable in retrospect, but so are some features of most random sequences—if the features are selected after looking at the data. For a variety of magnitude cutoffs and three statistical tests, the global catalog, with local clusters removed, is not distinguishable from a homogeneous Poisson process. Moreover, no plausible physical mechanism predicts real changes in the underlying global rate of large events. Together these facts suggest that the global risk of large earthquakes is no higher today than it has been in the past.

”

(your quotations emphasized). I believe their point is that it isn't enough to simply note that there have been more large earthquakes now than previously. In any random sequence there will always be some strange results, but we can't look at those anomalies in isolation. For example, if we flip a coin a thousand times and it's overall about 50-50, but the last 10 flips are all heads, we shouldn't immediately assume that the coin has recently become biased. Instead, we should consider the likelihood that chance alone could generate such a streak. I don't know enough about the math to evaluate their conclusion, but I think their premise is sound and I think you've mischaracterized it.--JustinD 01:04, 21 December 2011 (EST)

@Conservative: just take another course on statistics and you may find out the distinction between the Poisson distribution and a Poisson process.

@Aschlafly: increased disorder affects the Earth just as it affects everything else that's not a plausible physical mechanism, that's a philosophical statement.

AugustO 02:08, 21 December 2011 (EST)

Entropy is physics, not philosophy. If you don't think increased disorder affects the Earth, then please explain your view on whether perpetual motion machines are possible.--Andy Schlafly 23:30, 21 December 2011 (EST)

It also relates to the second law of Thermodynamics, which states that Entropy in a system must always increase. NickP 00:17, 22 December 2011 (EST)

Actually no; it states that entropy in a CLOSED system cannot DECREASE. It doesn't have to increase; it can remain constant. --HarryPagett 17:13, 22 December 2011 (EST)

• If I ask you: "How does a grandfather clock work?" and you answer with "gravity", you are somewhat right. But your answer isn't helpful, as you aren't describing a mechanism, you only invoke a general principle. That's not enough, a plausible physical mechanism has to be described in a little more detail. The same holds for answering the question: "What is the reason for earthquakes to occur?" with "entropy".
• Even though the the laws of thermodynamics hold, you can observe places on Earth where the entropy locally decreases - even without the help of an intelligent agent: Look a sky - do you see clouds? They show that water isn't distributed uniformly throughout the atmosphere. And even though there is the tendency to get to such a uniform distribution, we don't get rid of clouds. Why? Because new clouds are created. How do these abnormalities arise? Because there is an energy gradient, provided by the Sun, powering the water cycle.
• The same is true for processes in the Earth: here, an energy gradient is given by the radioactive elements.
• without these effects, the increasing entropy wouldn't result in more and bigger quakes, but in less and smaller, as disequilibria would be resolved over time.

AugustO 10:09, 22 December 2011 (EST)

Are you saying that earthquakes are partly caused by radioactive decay? That's interesting. I thought convection currents were the main factor.--CPalmer 10:24, 22 December 2011 (EST)

Indeed. But what creates the convection currents? The heat from within the Earth, mainly caused by radioactive decay. AugustO 10:31, 22 December 2011 (EST)

August, increasing disorder affects all processes. I didn't see a response by you to my perpetual motion machine question. Earthquakes, regardless of their mechanism, reflect the truth that perpetual motion machines are impossible. The corollary is that earthquakes must be increasing, just as disorder does for an attempt at a perpetual motion machine.--Andy Schlafly 11:55, 22 December 2011 (EST)

But earthquakes AREN'T increasing. They fluctuate from year to year but there just isn't a long-term increase. The trend is stable. --HarryPagett 14:02, 22 December 2011 (EST)

Exactly. It doesn't seem very helpful to discuss how or why earthquakes are increasing in frequency before we determine whether or if they're increasing. And the paper cited by AugustO claims that there is no increase, despite recent appearances. So before we talk about radioactive decay or tectonics, we should decide if the study is to be trusted. If it is, there's little benefit to discussing mechanics. --JustinD 16:34, 22 December 2011 (EST)

In addition, the other examples August listed were not closed systems; tectonics is a closed system. NickP 12:13, 22 December 2011 (EST)

No, it's not. --FrederickT3 12:44, 22 December 2011 (EST)

Let me clarify: We have a heat source at the center of the Earth, resulting mainly from decay of radioactive nuclei. We also have a heat sink at the surface (dissipation of energy due to earthquakes, volcano eruptions, a bit of radiation, etc.). Tectonics is caused by the temperature gradient inbetween, an open system. --FrederickT3 15:39, 22 December 2011 (EST)

• August, increasing disorder affects all processes. As does gravity. This is a general principle, to get a physical mechanism you need to fill in some details.
• I didn't see a response by you to my perpetual motion machine question. I thought my remarks on entropy were clear enough. But let's get back to your question: If you don't think increased disorder affects the Earth, then please explain your view on whether perpetual motion machines are possible. Of course, increasing disorder affects the Earth, just not the way you imagine it. Perpetual motion machines aren't possible. But an isolated system doesn't become more violent over time, it becomes more boring :-) All the models of things which were thought to be perpetual mobiles by their creators slowly grind to an halt, they don't disrupt themselves in quakes.
• The corollary is that earthquakes must be increasing, just as disorder does for an attempt at a perpetual motion machine. That's not a corollary, that is just wrong, and won't become true just by repeating it like a mantra. For an earthquake to happen, you have first to built up tension in a place - and that means lowering the entropy locally, using energy. When the earthquake happens, the energy stored is freed, entropy rises again.

AugustO 16:48, 22 December 2011 (EST)