Sunspots and earthquakes

I'm going to start out with a quote from the brilliant Randall Munroe, whose comic strip xkcd is rightly beloved by science nerds and tech geeks the world over.  (Go into any college science building, and check out the professors' office doors.  You'll find as many xkcd comic strips as you did ones from The Far Side twenty years ago.)

The quote is:  "Correlation does not imply causation, but it does waggle its eyebrows suggestively and gesture furtively while mouthing, 'Look over there!'"

The reason this comes up is because of a recent paper in Nature Scientific Reports called, "On the Correlation Between Solar Activity and Large Earthquakes Worldwide."  The authors, Vito Marchitelli and Paolo Harabaglia (of the Università della Basilicata of Potenza, Italy), and Claudia Troise and Giuseppe De Natale (of the Istituto Nazionale di Geofisica e Vulcanologia of Naples) investigated a claim that was first made over a century and a half ago; that there is a connection between solar activity and earthquake frequency.

The first scientist who noticed this was the Swiss astronomer Rudolf Wolf, who also noted the 11.1 year cyclicity of sunspot frequency.  Sunspots are basically solar storms, regions where there is such a high concentration of magnetic flux lines that it inhibits convection and generates a region that is a little cooler and darker than the surrounding parts.  (A sunspot's darkness is relative; isolated from the rest of the bright disk of the Sun, a sunspot would have about the same luminosity as the full Moon, and would glow bright orange.)

Sunspots are also connected to some of the most violent activity our Sun engages in; solar flares, prominences, coronal loops, and coronal mass ejections.  Each of these is basically a different kind of enormous explosion on the Sun's surface, and results in a huge increase in the subatomic particle flux surging outward into the Solar System.  Our atmosphere protects us from some of that bombardment, but it's detectable on the Earth's surface not only with sensitive instruments but because it triggers the brilliant and gorgeous auroras near the poles.

It's not without its hazards, however.  Large events such as coronal mass ejections can damage or disable satellites, and because of the charged nature of the particles, can induce electrical activity in wires and potentially knock out the terrestrial electrical grid.

[Image is in the Public Domain courtesy of NASA]

But Marchitelli et al. found -- or, rather, confirmed Wolf's claim -- that there is a correlation between sunspot activity and earthquake frequency.  So how the hell could that work?

First, let's rule out that it's some kind of spurious correlation, such as the wonderful discovery by Tyler Vigen that per capita cheese consumption year-by-year correlates almost perfectly with the number of people who died from becoming tangled in their bedsheets.  Of course, you can correlate almost anything with anything else if you cherry-pick your data carefully enough; and there are statistical methods to catch out that sort of thing.  Here, an application of those statistical methods to the sunspot/earthquake correlation led to a vanishingly small -- less than 0.00001 -- chance that what they were looking at was not meaningful.

So what's going on here?  Turns out the likeliest explanation has to do with the induction of electrical activity I referenced earlier.  And this is where I had to stifle a chuckle.

If you read my piece "Vanished into the Wilderness" only a couple of days ago, you may remember that one of the goofy explanations proffered for unexplained disappearances of hikers is "the piezoelectric properties of granite."  Piezoelectricity is the property of certain substances to develop a charge if they're put under pressure; it's been thoroughly studied and in fact has a multitude of uses in technology, including push-start ignition on propane grills, the timekeeping device inside a quartz watch, and amplification pickups in electric guitars.

The key to how this could trigger earthquakes has to do with the fact that the piezoelectric effect works both ways; pressing on a piezoelectric substance induces a charge, and charging it induces a change in shape (altering the pressure).  So what Marchitelli et al. suspect is going on here is that the dramatic increase in charged particle flux striking the Earth during a peak time of sunspot activity is creating a piezoelectric change in the pressure of the rocks the particles are passing through -- generating a tension that makes it more likely for a stressed fault to rupture.

What's fun about all this is that not only do we have a correlation, but we have a possible mechanism explaining it.  That's often the problem; there might be odd correlations out there, but absent a plausible mechanism, chances are we're looking at something like Tyler Vigen's discovery that the number of letters in the winning word of the Scripps National Spelling Bee correlates with the number of people worldwide who are killed yearly by venomous spiders.  Here, we are looking at a meaningful correlation.

It also shows that we're being affected by forces of which the average person is entirely unaware.  Which is kind of cool but kind of scary.  It makes me wonder what other things are happening out there that are exerting influences on the world around us in strange and subtle ways.

For what it's worth, I still think that astrology, with all its alleged correspondences between the positions of the planets and stars and people's personalities and fates, is bunk.  And even if piezoelectricity might explain the connection between sunspots and earthquakes, I maintain that it doesn't have a damn thing to do with hikers disappearing.

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Humans have always looked up to the skies.  Art from millennia ago record the positions of the stars and planets -- and one-off astronomical events like comets, eclipses, and supernovas.

And our livelihoods were once tied to those observations.  Calendars based on star positions gave the ancient Egyptians the knowledge of when to expect the Nile River to flood, allowing them to prepare to utilize every drop of that precious water in a climate where rain was rare indeed.  When to plant, when to harvest, when to start storing food -- all were directed from above.

As Carl Sagan so evocatively put it, "It is no wonder that our ancestors worshiped the stars.  For we are their children."

In her new book The Human Cosmos: Civilization and the Stars, scientist and author Jo Marchant looks at this connection through history, from the time of the Lascaux Cave Paintings to the building of Stonehenge to the medieval attempts to impose a "perfect" mathematics on the movement of heavenly objects to today's cutting edge astronomy and astrophysics.  In a journey through history and prehistory, she tells the very human story of our attempts to comprehend what is happening in the skies over our heads -- and how our mechanized lives today have disconnected us from this deep and fundamental understanding.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

A hue and cry over sunspots

The argument from ignorance is a curious phenomenon.

The gist is that people take their lack of understanding of some phenomenon, and from that ignorance deduce that their own particular explanation must be the correct one.  Of course, you can't deduce anything from a lack of understanding.  As Neil deGrasse Tyson put it, "If you don't know, that's where your conversation should stop.  You don't then say that it must be anything."

I saw a particularly good example of the argument from ignorance a couple of days ago, with the hoopla that is arising around a mysterious action by the FBI over a solar observatory in New Mexico.  On September 6, the Sunspot Solar Observatory near Alamogordo, a research facility operated by New Mexico State University, was closed without explanation and all of its staff sent home.  The observatory has been closed since then, and all requests for more information have been met with steadfast silence.

Alisdair Davey, a data center scientist at the National Solar Observatory, which works with the SSO, said, "We have absolutely no idea what is going on.  As in truly nothing, which in itself is just weird."

The Richard B. Dunn Solar Telescope at the SSO [Image licensed under the Creative Commons uıɐɾ ʞ ʇɐɯɐs from New York City, USA, Richard B. Dunn Solar Telescope (5508694434), CC BY-SA 2.0]

What is even more peculiar is that a post office on the grounds of the SSO has also been shut down without explanation.  Rod Spurgeon, a USPS spokesperson, said he didn't think the two were related.  "Whatever’s occurring there has nothing to do with us...  I haven’t heard of anything like [a biohazard or bioterror incident] going on."  Liz Davis, a public information officer at the U.S. Postal Inspection Service, concurs.  "There is no criminal activity, which is what Postal Inspection Service would be dealing with," Davis said.

So as of right now, what we have is... nothing.  And there's nothing like nothing to get the conspiracy theorists having multiple orgasms.  This becomes obvious if you peruse prominent conspiracy theory websites, which I did so you won't have to do so and risk valuable brain cells.  Here are just a few of the ideas I've seen, all of which were presented as if they were statements of fact:

• The SSO sighted the spacecraft of an advanced alien race with which the US government is having dealings, so the whole place was shut down to prevent anyone from finding out more.
• The SSO intercepted a top-secret communiqué from a top-secret government satellite, and the result is that all of the staff has been rounded up and put under house arrest until they'll sign non-disclosure agreements.
• Because the SSO isn't far from Roswell, something something something crashed spaceship in 1947 something something.
• The SSO discovered that a solar flare was on that way that was going to incinerate the Earth, and the powers-that-be didn't want the astronomers telling everyone and causing havoc.  Given that the observatory closed on September 6, and here we all are, un-incinerated, you'd think this one would have been discounted.  Maybe this is a really slow-moving solar flare, I dunno.
• Some of the scientists at the SSO found out that the secret mission of the facility was using magic tractor beams to mess with the weather, and they had to be silenced.  The argument here, if I can dignify it with the name, is that since HAARP closed down a couple of years ago, the Evil Government Weather Manipulation Program had to be moved elsewhere, and this is the elsewhere to which it had been moved.  The fact that in the last few days we've seen two amazingly powerful killer storms -- Hurricane Florence and Typhoon Mangkhut -- is displayed as "evidence."  Because powerful hurricanes don't occur every year, or something.
• The FBI took over the SSO because they're going to modify the station to send out mind-control rays and turn Americans into mindless sheep.  From the fact that 36% of us apparently still support Donald Trump, it appears to be working.

And so on.

What, you may ask, do I think about all this?  Easy: what I think about all this is...

... I don't know.

'cuz that's what you say when you have no information.  I agree with the conspiracy theorists insofar as the FBI's action is rather curious; what earthly reason they could have to take over a remote solar observatory without explanation is beyond me.  It may be that at some point we'll find out why the incident happened, or -- because we're talking about the FBI, here -- we may never know.

Which, of course, will just fuel the conspiracy theorists further.  More nothing?  Yay!  That just proves we're right!

But if we're going to approach this whole thing skeptically, we have to be willing to allow ourselves to remain in ignorance -- indefinitely, if need be.  It's not a comfortable position for a lot of us.  People like to have explanations for things.  Certainty is reassuring.  The universe makes sense, everything has a reason.

To once again quote Tyson, "You can't be a scientist if you're uncomfortable steeped in ignorance.  Because scientists are always at the edge of what is known.  If you're not at the edge, you're not doing science."

In any case, keep an eye on the news, and watch out for stories about spaceships or satellites or weather modification or mind-control rays.  Or, perhaps, some more reasonable explanation of what happened.

The latter is what I'd put my money on.

UPDATE (as of Tuesday morning) -- the SSO has reopened, and while the details are still not entirely clear, authorities are saying that "a suspect in the investigation potentially posed a threat to the safety of local staff and residents."

See?  I told you it wasn't aliens.

There's still no information on exactly what kind of threat the suspect posed.  That should settle that, but of course it won't, because the conspiracy theorists will take the lack of details and spin that into a whole new set of claims.  You can't win, which we sort of already knew.

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This week's Skeptophilia book recommendation is a fun one.  If you've never read anything by Mary Roach, you don't know what you're missing.  She investigates various human phenomena -- eating, space travel, sex, death, and war being a few of the ones she's tackled -- and writes about them with an analytical lens and a fantastically light sense of humor.  This week, my recommendation is Spook, in which she looks at the idea of an afterlife, trying to find out if there's anything to it from a scientific perspective.  It's an engaging, and at times laugh-out-loud funny, read.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]

When the volcano blows

A recommendation for bloggers and other commentators: if you are going to write about science, make sure you understand the damn science.  And for readers: make sure you find out about the writer's biases.

This comes up because of a link sent to me by a loyal reader of Skeptophilia called, "Why Volcanic Eruptions and Earthquakes are Increasing."  The whole thing pivots on the scary idea that the Earth is becoming more tectonically active, which certainly would have a major impact on humanity.  But let us begin with the most pressing question, which is: are volcanic eruptions and earthquakes increasing?

Mt. Nyiragongo, Democratic Republic of Congo [Image licensed under the Creative Commons MONUSCO/Neil Wetmore, An aerial view of the towering volcanic peak of Mt. Nyiragongo, CC BY-SA 2.0]

The answer appears to be "no."  According to the site Volcano World, maintained by the geology department of Oregon State University, there is no evidence that there's more seismic or volcanic activity lately.  Not even a slow overall increase over the past few thousand years.  The appearance that there's more rumbling going on, they say, is due to two things:

1. The Earth is being more intensively monitored now than any other time in its history, so we're more aware of even small events than we would have been.  This information then gets relayed all over the globe, increasing laypeople's awareness of what's going on.
2. Because of the increase in human population, the impact of these events has become much greater.  To use the example from the site, if the 2010 eruption of Eyjafjallajökull in Iceland had occurred in 1500, it's doubtful that it would have bothered -- or even been noticed by -- anyone but the Icelanders.

So we start out with a problem, which is that the central claim appears to be incorrect.  And in fact, if you're talking about violent eruptions, what we're seeing from Kilauea in the last few days is peanuts compared to the eruptions of Krakatoa, Tambora,and Toba in the Indonesian archipelago (respectively in 1883, 1815, and about 75,000 years ago) and the Lake Taupo (New Zealand) eruption in 180 C. E.  And even those pale by comparison to the events that formed the Columbia River Flood Basalts, the Deccan Traps, and the Siberian Traps, the latter of which spewed out 4 million cubic kilometers of lava, an amount that beggars belief, and which is believed to have played a role in the Permian-Triassic Extinction that wiped out 95% of the species on Earth.

But never mind all that.  The next thing the authors throw out is their explanation for this increase (which, recall, isn't occurring anyhow).  And the answer is: cosmic rays.

My first inclination was to guffaw at this, but then I decided to do some research (always a good idea, especially when there's the likelihood of rejecting an idea solely because "it seems wrong").  And I found that there is a (scientific) claim out there that the timing of volcanic eruptions is correlated with sunspot minimums, because those are correlated with a higher cosmic ray flux.  The paper in question is "Explosive Volcanic Eruptions Triggered by Cosmic Rays: Volcano as a Bubble Chamber," by Toshikazu Ebisuzaki, Hiroko Miyahara, Ryuho Kataoka, Tatsuhiko Sato, and Yasuhiro Ishimine, of the RIKEN Advanced Science Institute and the University of Tokyo, which appeared in Gondwana Research back in 2011.  What the scientists propose is that for silica-rich volcanoes, the magma can become superheated, and a cosmic ray could act to trigger nucleation -- quick, explosive liquefaction.

But here's the problem.  The Ebisuzaki et al. study only looked at eleven volcanoes, all in Japan, which already seems like a pretty small sample size.  They found that nine of the volcanoes erupted during a solar minimum, and the other two nearer to a solar maximum.  But without even trying hard I went through some eruption records back to 1700 (the cutoff for their study) and found twelve more stratovolcano eruptions (volcanoes with explosive, silica-rich magma) -- Pinatubo (1991), Mount St. Helens (1980), Novarupta (1912), Santa Maria (1902), Mount Pelée (1902), Krakatoa (1883), Tambora (1815), and La Soufrière (1718, 1812, 1902, 1971, and 1979).  Of those, eight occurred during solar maximums; only two (Novarupta and the 1971 eruption of La Soufrière) were during a clear minimum.  Two eruptions, Tambora and the 1812 eruption of La Soufrière, occurred during a local maximum in the middle of a thirty-year period of overall low sunspot activity (the "Dalton Minimum").  So let's not count those in either column.

So with my additions, that brings us up to twenty-one eruptions -- eleven during minimums, and ten during maximums.

In other words, random chance -- no connection to sunspot activity whatsoever.

Now, I'm neither a geologist nor a statistician, and if there's something wrong with my reasoning, I'm happy to correct it.  But I haven't even hit the punchline yet: the whole thing winds its way around to the claim that the Earth isn't actually warming, it's cooling.

So we're back in climate change denial la-la land, which I should have realized the moment I read them quoting Roy W. Spencer, a meteorologist who is on the advisory board of the denialist, pro-fossil-fuels Heartland Institute.  The site Skeptical Science takes Spencer's claims apart one at a time, and with far more authority than I can wield, so I suggest perusing the site.

Anyhow, the original claim looks like bullshit to me, and yet another example of someone with an ax to grind cherry-picking data that supports what they would very much like to be true.  In any case, I think we can rest assured that the cosmic rays aren't going to cause volcanoes to erupt, and that volcanic eruptions in any case have been pretty frequent occurrences throughout Earth's history.  Me, I'm more worried about the fact that we're still burning fossil fuels like mad despite a near-universal scientific consensus that what we're doing is going to jeopardize the long-term habitability of the planet.  And that seems to me more important than fretting about sunspots and cosmic rays.

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This week's book recommendation is a brilliant overview of cognitive biases and logical fallacies, Rolf Dobelli's The Art of Thinking Clearly.  If you're interested in critical thinking, it's a must-read; and even folks well-versed in the ins and outs of skepticism will learn something from Dobelli's crystal-clear prose.

Sunspots and ice ages

If there's one feature of media that drives me the craziest, it's the practice of appending the words "scientists claim" to any damn thing they want to in order to give it unwarranted credibility.

Take, for example, the story that appeared over at RawStory (and also, in similar forms, at The Telegraph and The Daily Mail).  Entitled "'Mini Ice Age' On the Way In 15 Years, Say Scientists," this article takes a piece of legitimate and interesting scientific research and puts a sensationalized spin on it that, if I were one of the researchers, would impel me to write a rebuttal comprised of a single sentence: "I DIDN'T SAY THAT."

First, a little background.  The number of sunspots, which are electromagnetic storms on the surface of the Sun, has been observed to fluctuate on a cycle of about eleven years, but also to be subject to a second (much longer-period) cycle of 370-odd years.  This is the proximal cause of the Maunder Minimum, a time of low sunspot activity that lasted from 1645 to about 1715.

Sunspots in September 2001 [image courtesy of NASA]

Thus far, this probably would merit nothing more than a "So what?" from everyone but astronomy buffs.  Why would popular media even report on something like sunspots?  But the Maunder Minimum, at least in part, coincided with low temperatures in Europe -- the article in RawStory refers (correctly) to the Thames freezing over in winter during that period (although, as you'll see, even that is only one cherry-picked piece of the truth).

So to put it bluntly, the whole purpose of this story is intended to cast doubt on anthropogenic climate change.  "Damn scientists!" you're left thinking.  "Can't even decide if the temperature is rising or falling!"

The problem is, this is a flaw in the media's reporting, not in the science itself.  Let's take this claim apart at the seams, okay?

First, let's look at the basis of the claim -- that the Maunder Minimum predicts extremely cold temperatures.  All it takes is a quick trip to Wikipedia to find out that it's not that simple:

Note that the term "Little Ice Age" applied to the Maunder minimum is something of a misnomer as it implies a period of unremitting cold (and on a global scale), which is not the case.  For example, the coldest winter in the Central England Temperature record is 1683-4, but the winter just 2 years later (both in the middle of the Maunder minimum) was the fifth warmest in the whole 350-year CET record.  Furthermore, summers during the Maunder minimum were not significantly different to those seen in subsequent years.  The drop in global average temperatures in paleoclimate reconstructions at the start of the Little Ice Age was between about 1560 and 1600, whereas the Maunder minimum began almost 50 years later.

If you want to go a little deeper than Wikipedia -- and you should -- check out this cogent and well-written summary of the problem with correlating sunspots and ice ages by Mike Lockwood, professor of space environment physics and a director of research at the University of Reading.  Lockwood writes:

There is very little evidence that the lower global mean temperatures between 1400 and 1800 were caused by solar activity - there's more evidence it was associated with volcanic activity and/or internal oscillations in the climate system...  Much of what has been written in the media and on the internet fails to appreciate the difference between regional and global climates.  My research looks at a potential link between low solar activity and cold European winters. That's a regional and seasonal effect and not a global effect.

If that wasn't unequivocal enough for you, Lockwood goes on to say, "What's more, there's no evidence that summers in the Maunder minimum were any colder than usual.  This is not a 'Little Ice Age' - it is not an ice age of any shape or form."

Second, let's check and see if the scientists cited in the RawStory article actually said anything about an ice age starting in fifteen years.  The lead researcher, Valentina Zharkova of Northumbria University, presented her findings at the National Astronomy Meeting in Llandudno, Wales last week, and a summary appeared in Phys.org.  Here are a few relevant paragraphs:

It is 172 years since a scientist first spotted that the Sun's activity varies over a cycle lasting around 10 to 12 years.  But every cycle is a little different and none of the models of causes to date have fully explained fluctuations.  Many solar physicists have put the cause of the solar cycle down to a dynamo caused by convecting fluid deep within the Sun. Now, Zharkova and her colleagues have found that adding a second dynamo, close to the surface, completes the picture with surprising accuracy. 

"We found magnetic wave components appearing in pairs, originating in two different layers in the Sun's interior.  They both have a frequency of approximately 11 years, although this frequency is slightly different, and they are offset in time.  Over the cycle, the waves fluctuate between the northern and southern hemispheres of the Sun.  Combining both waves together and comparing to real data for the current solar cycle, we found that our predictions showed an accuracy of 97%," said Zharkova... 

Looking ahead to the next solar cycles, the model predicts that the pair of waves become increasingly offset during Cycle 25, which peaks in 2022.  During Cycle 26, which covers the decade from 2030-2040, the two waves will become exactly out of synch and this will cause a significant reduction in solar activity. 

"In cycle 26, the two waves exactly mirror each other – peaking at the same time but in opposite hemispheres of the Sun.  Their interaction will be disruptive, or they will nearly cancel each other.  We predict that this will lead to the properties of a 'Maunder minimum'," said Zharkova.  "Effectively, when the waves are approximately in phase, they can show strong interaction, or resonance, and we have strong solar activity.  When they are out of phase, we have solar minimums.  When there is full phase separation, we have the conditions last seen during the Maunder minimum, 370 years ago."

Is it just me, or did she say nothing about "ice ages?"

But the Maunder Minimum was cold, right?  Couldn't we still see a drop in temperatures if the predicted minimum occurs?  To answer that question, let's go back to Lockwood:

Statistically, we found a significant link between the occurrence of cold winters in the long CET record and solar activity.  By "significant" we mean that there was only a five per cent chance that we were being fooled by a coincidence...  In a paper with scientists from the Met Office's Hadley Centre, we used an energy balance model to show the slowing in anthropogenic global warming associated with decline in solar irradiance to Maunder minimum levels.  We found the likely reduction in warming by 2100 would be between 0.06 and 0.1 degrees Celsius, a very small fraction of the warming we're due to experience as a result of human activity.

Which hits on the central point.  My suspicion is that the hype surrounding the Maunder Minimum and sunspots has one purpose: to reassure us that our activity isn't going to warm the Earth further, and push the climate more out of whack than it already is.  "Don't worry," the media tells us.  "Keep burning your fossil fuels.  The Earth is going to be just fine.  In fact, we might be heading into an ice age!"

And because few people read any deeper than what appears in popular media, they're left with the further impression that the scientists don't know what the hell they're talking about.  We hear about global warming, and then there's an article where "scientists claim" that everything is cooling off.  Is it any wonder that laypeople throw their hands in the air and stop listening?

Which, of course, is what a lot of the powers-that-be want.  Altering the status quo is expensive, and requires unhooking our government from the influence of the fossil fuel industry.  No way can we have that happen.

No way.

Easier to slip into the media misleading stories that subtly cast doubt on the research itself, along with those nasty little words -- "scientists claim."  After that, they can sit back and let natural cynicism and distrust do the rest.