Water on Mars

Water has been found on Mars. But it's not the first time.

Water has been found on Mars. But it’s not the first time.

Not since Schiaparelli published his drawings of Martian “canals” has the popular press been so excited about water on Mars. Giovanni Schiaparelli, an Italian astronomer, science historian, and senator, had a good clear view of Mars through his scope back in 1877. And that’s when the troubles began. But it wasn’t all his fault.

In 1877, Mars was in opposition – an astronomical term that does not describe a state of feisty parliamentary politics but simply means that Mars was close to the Earth. In opposition, the Sun, Earth, and Mars form a straight line. The planet is millions of kilometers closer than usual, it lingers in the night sky, rises in the evening, sets at sunrise, and presents a fully illuminated face towards the Earth. Having a strong opposition, astronomically speaking, is a good thing.

Schiaparelli’s view of Mars was so spectacular that astronomers call 1877 the year of  “The Great Opposition”.  The favourable opposition enabled Schiaparelli to sketch and name the continents and oceans of Mars. (According to Schiaparelli, Mars has places named Utopia, Eden, Arabia, Libya, and the Australe Sea.) But most famously, he mapped Martian channels. These were broad waterways that, to him, seemed to start a few hundred kilometres from both Martian polar ice caps and appeared to carry water to the parched red prairies where farmers (as efficient as any of their 19th century earthling colleagues) made the deserts bloom.  At least this became the popular assumption shortly after Schiaparelli’s channels (canali, in Italian) were mistranslated as canals in English.

Use say channels; I say canals. Schiaparelli's 1888 Mars map.

You say channels; I say canals. Schiaparelli implied both on his 1888 Mars map.

Many of us possess lively imaginations that run more quickly than cautious reasoning. A prime example was a wealthy American, Percival Lowell. The Lowell family started as an ancient clan of Brits in America, the first of whom was also named Percival Lowell, a 1639 Newbury, Massachusetts, settler and merchant.

The 20th century astronomer, Percival Lowell, had well-connected siblings. His brother, Abbott Lowell was president of Harvard (1909-1933) and distinguished himself by limiting the number of Jewish students allowed into Harvard and by banning black students from living on-campus in dorms. Lowell’s parents did not allow his sister, Amy Lowell, to attend college – because she was a girl. Amy Lowell was brilliant and became a self-educated, obsessive, collector of books. In 1926, she was posthumous awarded the Pulitzer Prize for her feminist poetry.

Percival Lowell (1855-1916) had the money and enthusiasm to pursue anything that attracted his attention. He studied math at Harvard where his graduation speech was a discourse on the nebular theory, the idea that the solar system formed from the coalescence of nebulous matter. His talk in 1872 was unusually bold and decades ahead of his time, though he didn’t create the nebular hypothesis. (That credit goes to Immanuel Kant.)  What does an agnostic cosmologist with a  math degree do after Harvard? Percival Lowell ran a cotton mill for six years. Then it was off to Japan.

Lowell spent about ten years in the Far East. His travels led to a series of books about oriental culture, language, education, personality, and religion. Those years also forged his own philosophy that centered on the idea of human progress as a function of human imagination.  Unfortunately, his imagination would eventually take a bite out of his reputation.

Mars Hill, Lowell's Flagstaff observatory.

Mars Hill, Lowell’s Flagstaff observatory in 1910.

Astronomy caught Lowell’s attention. With his wealth and connections, he pursued his hobby in an effusive manner. He studied American geography, looking for a place with dry clear night skies. A perfect place to set up a telescope. So he went to Flagstaff, Arizona, and built an observatory on a hill.

Lowell Observatory was home to one of  the best telescopes in America when it opened in 1896. The first instrument was a 24-inch Alvin Clark telescope, assembled in Lowell’s home town of Boston. It cost $20,000. From there, the instrument was carried across America to its permanent home on Mars Hill in Arizona. The Lowell Observatory is still in operation, still overseen by a trustee who is a member of the Lowell family, and telescopes there are still used there to peer into the sky. The observatory’s greatest achievement was the discovery of Pluto, made with a 13-inch telescope in 1930.

But it was Mars that enchanted Percival Lowell. And consumed his spirit. He believed in the Martian canals and the importance of the water they channeled towards Mars’ equator. In his 1906 book, Mars and its Canals, Lowell wrote:

To Schiaparelli, the republic of science owes a new and vast domain. His genius first detected those strange new markings on the Martian disk which have proved the portal to all that has since been seen and his courage in the face of universal condemnation led to exploration of them. He made there voyage after voyage, much as Columbus did on Earth, with even less of recognition from home. As with Columbus, too, the full import of his great discovery lay hid even to him and only by discoveries since is gradually resulting in recognition of another sentient world.

Yes, another sentient world. Just like the Earth. In his 456-page book about Martian canals, Lowell builds his case for the existence of thinking, feeling, intelligent life on Mars. A section is devoted to the polar caps with their seasonal ring of blue flood water, another describes the vegetation Lowell could see seasonally changing the planet’s colour. Satisfied that he had proven to himself that plant life grew on the red planet, he admits that animal life on Mars is more difficult to spot with a telescope, even one as advanced as the instrument he had in Arizona. However, in a chapter called Evidence, Lowell writes:

“Not until the creatures had reached a certain phase in evolution would their presence become perceptible; and not then directly, but by the results such presence brought to pass. Occupancy would be first evidenced by its imprint on the land; discernible thus initially not so much by the bodily as by the mind’s eye. For not till the animal had learnt to dominate nature and fashion it to his needs and ends would his existence betray itself. By the transformation he wrought in the landscape would he be known.”

Lowell concluded that technologically advanced Martians had built the canals in an effort to postpone the certain demise of their civilization as their planet dried and died. From Earth, from his perch at 1400 West Mars Hill Road, in Flagstaff, Arizona, Percival Lowell watched the fall of a once proud and noble Martian civilization.

And this led to the fall of Lowell. With weak, faulty evidence, he reached a conclusion supported by little more than optical illusions seen on fuzzy images, encouraged by like- minded dreamers and his own powerful imagination.

Lowell died relatively young, at age 61. Within his lifetime, his Martian canal observations were never confirmed by serious astronomers, nor did it seem likely that his maps of the surface of Venus or his speculation of the existence of Planet X would ever prove true. It was widely suspected that stress, disappointment, and embarrassment contributed to Lowell’s death.

But he was not the failure that he felt he was. For one thing, Lowell mathematically predicted that a planet beyond Neptune must exist because of apparent gravitational interference with Neptune’s orbit. His Planet X speculation was vindicated 15 years after his death when Clyde Tombaugh used Lowell’s Flagstaff observatory and discovered Pluto. Just as importantly, Lowell fostered interest in astronomy and invested heavily in its popularization. He was arguably the most influential American astronomer until Carl Sagan came along decades later.

Lowell’s imagination also made a huge contribution to exploration and discovery. The idea of advanced civilizations on distant planets ignited wonder and awe in countless science fiction fans who grew into mature scientists. Some even became involved in the modern Mars explorations which have found running water on the planet’s surface, one hundred years after Lowell’s death.

NASA’s announcement of the discovery of water on Mars has once again roused the imagination of dreamers. Upon hearing the news, most of us immediately thought, “Water? Then maybe there’s life on Mars.” Sure, we accept that Martian life will not include an aging advanced civilization. But these days, the discovery of a couple of replicating strands of molecules found on another world will be every bit as thrilling.

There is just one more thing to round out this story. Remember the water channels? Here is a NASA photograph of the briny rivers flowing on Mars. The rivulets appear as a series of dark streaks. They look a lot like canals.

Seasonal ephemeral rivers (or maybe canals?) on Mars.

Seasonal ephemeral rivers (canals?) on Mars

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The Four-Legged Snake and the Bible

Serpent in Garden of Eden Before the Fall

Serpent in Garden of Eden Before the Fall – by conceptual artist Mark Dion
on display at the Museum of Biblical Art.


Martin Luther said that snakes were once four-legged cuddly creatures of the field. It’s in the Works of Luther, should you wish to read his theory. This summer’s news that a fossil was identified as a “four-legged snake” has a number of Creationists cheering about palaeontology. The Bible tells them that after the talking snake tempted Eve with some seedy pomegranate, God cut off all the snake’s legs, leaving the reptile squirming on its belly. God also rearranged the snake’s DNA and all subsequent issues of snakes were similarly hoofless.

Until this summer, fossil relics of four-legged snakes were in short supply. Well, actually, there weren’t any at all. This didn’t disturb most Creationists because they are comfortable believing the world began (on a Saturday night) just a few days before the pomegranate incident in the garden. Not much time to accumulate many four-legged snake fossils. Nevertheless, you can find websites full of glee for this new discovery. It proves God had created at least one four-legged snake before causing its appendages to detach.

The real story of the fossilized  Tetrapodophis, or four-legged snake, has legs of its own. David Martill, a British palaeobiologist, was leading a group of 3rd-year palaeontology students through a Berlin museum where Brazilian fossils were on view at a temporary display. Next to a placard labeled “Unknown” was the snake fossil. Professor Martill studied the rock for a moment: “I thought, ‘Bloody hell, it’s got back legs!'” Then he noticed the snake also had front legs. Martill is a respected expert on Brazilian Cretaceous fossils. He knew that a snake like this – with four legs – had never been seen before.

Martill's four-legged snake

Four-legged snake. The hind legs are clearly visible,
especially in the image below.  From Martill et al. (2015).

fossil snake rear legs

This discovery is incredibly significant. Biologists expected that an evolutionary link might exist between lizards and snakes but until Martill’s accidental discovery, none had been found. Further, the creature has microscopic fossil bones in its stomach (indicating it was a carnivore), a bone assemblage that suggested it was a burrower, snakey scales (not lizardy scales), and, Martill thinks, the fossil is embedded in Aptian-age Cretaceous rock, making it nearly 120 million years old – much older than any other snake fossil.

Unfortunately, the story is not so tidy. The fossil is an undocumented artifact. It was found on a museum shelf, part of a visiting display. Just in town from Brazil for a few days.

No one is suspecting any funny business. It is what it is. (You can’t make these things in the basement.) Radioactive testing, microscopic examination, chemical analysis and CT scanning tell the truth. But it would have been darn nice to know exactly where it was dug up in Brazil, and what rocks were lying beside and below its discovery spot.

Meanwhile, a few scientists are not so certain that the find is actually the modern snake’s ancestor. In particular, Dr Michael Caldwell at the University of Alberta thinks it looks more like a descendant of an even older, non-snake creature. The skull and spine don’t seem right for a snake ancestor, he says. And Caldwell should know, his research includes the evolutionary history of snakes and lizards. At the moment, he is cautious about the museum piece’s pedigree as the ancestor of all snakes, though he says it otherwise may have great importance as a long-lost lizard descendant.

How are the faithful taking all this? I’ve noticed a dozen popular religious websites which seem to feel this vindicates traditional sermons that before the snake turned bad, it was a soft, friendly, meek and mild four-legged beast of the field. You can catch the good news at Shoebat’s: For The First Time Ever A Snake With Legs Has Been Discovered, Proving The Bible To Be True That The Serpent Originally Had Legs and the always reliable Answers in Genesis, which posted Did the Serpent Originally Have Legs? (Don’t bother feeding them click-credit – their answer (in Genesis, as they see it) is Yes. It’s in the Bible.

Maybe you’re not overwhelmed by the wonderful Old Testament Bible story about fruits and snakes. Perhaps you find the New Testament more relevant.  In that case, you will be delighted to learn that a virgin birth by a Missouri snake was also in the news this summer. After living alone for seven years she somehow managed to have little baby snakekins. No one knows how. But it does prove that virgin births are scientifically possible.

Okotoks - aka Big Rock

Okotoks – aka Big Rock

If we want to prove the scientific validity of very old religions, we can’t forget the Okotoks Rock. Lying out on the flat prairie just south of my home here in Calgary is a mysterious big rock. The aboriginals called Big Rock Okotoks in their language. The rock is incredibly out of place, a boulder the size of a large 3-storey home sitting on wide-open farmland. Geologists claim that it’s an ice-age erratic. They think it was carried by a glacial train originating 500 kilometres north. They theorize that it was abandoned when the last prairie glacial ice melted. It has huge cracks caused by freeze-thaw cycles which have splintered the main boulder.

But aboriginal legends tell a far more enchanting tale. The Creator god Napi had offered his robe to the rock but Napi took it back when the weather turned cold and the Creator had a chill. The rock chased Him. Finally (and this part may be just a myth), a bird farted on the rock, knocking it from the sky, allowing Napi to escape. The rock shattered. Perhaps the story is true – scientific evidence is there for all to see: a huge out-of-place fractured rock, lying on the prairies. Does anyone really need any more proof than that to validate their belief?

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Break-up of the Animals

I just saw this in The Onion. When I lived in Wisconsin some years ago, we considered The Onion to be the state’s finest newspaper. Since then, they got into the digital age and I suppose they dropped the pulp and ink. But their website kept their gift of satire. And fun.

Here is a link to Onion’s latest science tom-foolery, a story about a Penn State research scientist who discovered Earth’s Animals One Giant Creature Before Breaking Apart Millions Of Years Ago. I linked their picture of what the planet looked like during the Mesozoic, just before the animals broke apart – you’ll have to go to their site to get the whole story.

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Geosyncline Celebration

James Hall, American geologist and paleontologist. (1811-1898)

James Hall, American geologist and paleontologist. (1811-1898)

Today, September 12, commemorates the 1811 birth of James Hall, Jr., an American geologist (and one of the world’s first paleontologists). Hall was brilliant. But dangerous. And, as often happens in science, his most stunning idea was eventually proven wrong. But for a few decades, the geosyncline theory of mountain building was one of the best ideas in geology.

For at least 30 centuries, people had wondered about the origin of mountains. By the 1800s, a few reasonable ideas emerged. Some geologists guessed that mountain ranges were the result of the planet’s cooling, shrinking  skin. Mountains are Earth’s wrinkles, they figured. On the other hand, others believed that mountains rose because the planet is expanding. The correct answer is plate tectonics. But the idea of colliding continents was still a hundred years away when James Hall presented his novel geosyncline idea.

Cross-section of New York to Vermont (Mio)Geosyncline.

Early 20th-Century Cross-section of New York to Vermont (Mio)Geosyncline

Hall explained mountains in terms of regurgitated sediment becoming deposited in shallow basins (usually where continents and oceans met). They filled up, heated up, and bounced up after they underwent thermal expansion. Geothermal rebound in or near geosynclines (a word Hall invented) made sense.

It was supported, in a way, by Charles Lyell, the great Scottish geologist and friend of Charles Darwin. Lyell is sometimes credited with inventing modern geology. His words certainly carried a lot of weight. Lyell agreed that heat expands rocks and helps build mountain ranges. In his influential Principles of Geology, Lyell calculated that 500 metres (about 1600 feet) of a typical mountain’s height is simply due to heated, expanded rock. Not enough to make an Alp, but enough to cause geologists to consider the role played by thermal expansion.

The great Charles Lyell lent respectability to James Hall’s idea, but it was a short-term loan. Hall had a strong ego and an irascible personality that drove a  wedge between most geologists and Hall. It would be the same with Charles Lyell, as we will see.

Hall had been appointed New York state paleontologist in 1841. The reckless geologist reserved his sharpest attacks for his many enemies in the New York government, men in the legislature who were in a position to help him. His outbursts were infamous, making state assistance reluctant, which made Hall even more tempestuous. He kept a loaded shotgun next to his desk – he wasn’t known to have used it, but the intimidating weapon helped him win arguments.

Before detailing James Hall’s dispute with Charles Lyell, here is an example of Hall’s rash behaviour. Hall’s government office published geological outcrop maps. Hall had made several significant contributions to naming and defining geological eras and periods. He was an expert paleontologist and his fossils helped identify rock layers throughout New York. But the lofty style of his work was inaccessible to ordinary folks. That changed after James T. Foster, a New York school teacher, published a popular geological chart in 1849. The chart was rife with errors, but it was clever and popular. Hall was jealous and indignant, and set to kill.

He didn’t kill Foster. But in Albany, Hall slipped aboard a boat headed to New York City. The vessel was hauling Foster’s geological charts. Hall worried that if the prints reached New York and were released, European geologists would injure themselves laughing at the bucolic state of American science. During the night, Hall threw all the prints of Foster’s offensive chart into the Hudson River. Next, he and Harvard geologist Louis Agassiz published letters in the Albany papers, claiming that Foster’s work was a childish effort created by an amateur dabbling in science. The school teacher, James Foster, felt insulted. He sued Hall and Agassiz for the equivalent of a million dollars in today’s money. The subsequent libel suit entangled Hall, Agassiz, James Dana, and other geologists for two years but was finally dismissed by the judge. Meanwhile, America’s first ‘science’ trial brought favourable international attention to the callous Hall and to the other American geologists involved.

Charles Lyell in 1840.

Charles Lyell in 1840.

Hall’s volcanic temper also got him in trouble with Charles Lyell. Lyell was touring North America in 1841 and 1842. Lyell’s incessant questions and his habit of copying American geological maps began to irritate his hosts. They nicknamed Charles Lyell “The Pump” and stopped feeding him the maps and notes they had worked hard creating.

James Hall worried that Sir Charles Lyell would return to Britain and claim the Americans’ material as his own work.  In March 1842, a letter signed “Hamlet” appeared in a Boston newspaper. It charged Lyell with the scientific sin of geo-kleptomania. Hamlet was Hall and Hall was suddenly ashamed of himself for anonymously insulting such an esteemed guest. In his embarrassment, James Hall treated Charles Lyell with even more respect and deference than he deserved – Lyell had certainly exceeded the bounds of any visitor’s allotted indulgences. But Hall’s fresh attitude soothed the insult towards Lyell. In return, Charles Lyell was somewhat open to Hall’s account of mountain building.

In the geosyncline theory, mountain-building was counter-intuitively explained as a result of landslides that filled deep chasms. Layers of sedimentary sandstone, limestone, and shale found in mountains were due to massive accumulations of sediment that slid into huge near-shore chasms created by the weight of earlier eroded sediments,  buried deeper and deeper in geosyncline troughs. The accumulation of sediments became so thick they sank far down into the hot basement of the subsurface and melted. Eventually everything expanded because of heat, and rose high on the surface in the form of mountains.

The geosyncline theory was popular in North America. For one thing, it was a home-grown idea, invented and taught in America. The Europeans were stuck in a debate between a shrinking vs expanding Earth as the cause of mountains. In the USA, it was geosynclines that built mountains.

James Dana, at age 71

James Dana 1813-1895

Hall teamed up with James Dana, the popular head of Yale’s geology department, to flush out the details of the model.  Together, they concluded that erosion washes grains of rock off continents, dumping them into nearby seas where the weight of the grit depresses the sea floor. The amount of accumulated sediment becomes so enormous that the material pushes down thousands of metres. In the case of the Appalachians, Hall and Dana figured the depth of accumulation was about 12,000 metres just before those mountains rose from the depths. It is fairly easy to imagine huge depths of eroded materials. But finding a way to elevate these twisted hardened rocks back above sea level was problematic. The geologists assumed that the heat of the deep burial plus the pressure of the Earth expelled the geosyncline’s material, forming mountains – like toothpaste squeezed from a tube. It was a convincing theory, but unfortunately there were no existing active examples anywhere in the world that it actually happens.

Nevertheless, for lack of another way to explain mountains, the idea was accepted in the US for decades. The idea long outlasted James Hall, who lived 86 years, dying in 1898. It would take another 70 years before plate tectonics replaced geosyncline theory in America’s universities. By then, the idea had become so ingrained into the understanding of geology that it was hard to overturn it.

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Finding Oil and Gas where God Dumps Them

palinWell, here’s a great idea. Sarah Palin has offered to head the Department of Energy when Donald Trump becomes president. “I think a lot about the Department of Energy, because energy is my baby: oil and gas and minerals, those things that God has dumped on this part of the Earth for mankind’s use…”

There’s a lot I could write about the suitability of Sarah Palin as director of the Free World’s energy. I’ll start with her colourful way of describing how oil, gas, and minerals form. In her interview, she said something about God taking a dump.

I guess when a politician thinks the world is just 7,000 years old, the polit may really think of geological deposits in terms of God’s dumpings. I can’t imagine her understanding traps, sources, migration, and reservoir rock with respect to hydrocarbons. Perhaps she doesn’t even care how God dumps natural resources.  Does it matter? Should we worry if the next person to run the American Department of Energy and command its 30.6 billion dollar budget, 13,000 federal employees and 93,000 contract workers doesn’t know how the firm’s widgets are made? It’s probably enough that the head of the department is a big-picture thinker. A leader with spunk and talent, people skills and leadership. Besides, what could be more amusing than having two reality TV stars running the USA – Trump (Apprentice) and Palin (Amazing America)?

Someone who really knows energy.

Someone who knows energy.

At the end of the CNN interview, Palin added “it would be great to have someone who knows energy” in charge of the department. Surprisingly, she was talking about herself. So, besides knowing that God has dumped energy upon America, what else does she know? Like most Americans, Sarah Palin knows that Alaska has a lot of energy. She should know this better than most – she was once a briefly-serving Alaska governor. As such she was responsible for a lot of energy.

“20% of America’s energy comes from Alaska,” she told us while she campaigned for vice-president. Well, the actual amount was 3.5%, an unfortunate error that she repeated for months. We expect a high-level big thinker to have a grasp for high-level numbers. So it makes us wonder what she meant when she told us that she knows energy.

It startled me when Palin commented yesterday morning on CNN that she would like to lead Trump’s energy department. But perhaps I worry too much. Although Trump responded by saying he could use her as his energy chief, I should remember that Sarah Palin doesn’t stay long on any of her jobs. And as the future energy secretary, she is already finding a way out. She’ll shut it down and move on, perhaps to a reality TV series called “How I Destroyed America”.

Palin tells us that her role as the national energy head would be short-term because all the energy operations and resources would be turned over to the states. (I wonder if that includes stateless offshore oil and gas.)  She would give the resources to the people of each state to manage. Perhaps there’s some logic to that. Or perhaps not. States have long had their own regulatory and oversight boards governing everything from well spacing, fracking rules, reclamation projects, and recovery rates from fields. But I guess the states could always do more and the federal government less. There might be 50 different competing bureaucracies – none with a national vision –  but what could possibly go wrong with that?

Speaking American

Speaking American

Although she would like to run the energy department, then quickly close it, Palin fortunately demurs on running anything dealing with culture and is unlikely to become Secretary of State. For example, in the recent Republican controversy about Jeb Bush campaigning in Spanish, she praised his effort to reach out to those nice Hispanic people who make up “a large and wonderful” part of the country. However, Sarah Palin added that in America, we should all “speak American.”  But I doubt that she meant real American – for example Navajo, Cree, or Cherokee.

However, Sarah Palin isn’t afraid of languages other than her own variety of American. She says that she studied both French and Spanish in high school, adding, “I shouldn’t have taken them both, because I got them all mixed up by the time I was graduating.”   I betcha she did.


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What do We Really Think about Plate Tectonics?

In mid-August, two experts on acid rain published a study. It’s about Wikipedia and how wiki edits reflect some of the social dynamics of the public’s view of science.  The researchers – Adam Wilson and Gene Likens – indicated that they were frustrated. Wikipedia’s acid rain entry had been repeatedly vandalized with obscenities and nonsense. The culprit(s) were likely editors who disagreed that precipitation can become contaminated with sulphuric acid and that such pollution can cause environmental damage. The vandals were apparently unable to express their opinions through reasonable logical arguments supported by facts. So the renegade editors deleted large sections of material and inserted vulgarities and wiki-graffiti. For example, the opening paragraph was once briefly replaced by “Acid rain is a popular term referring to the deposition of wet poo and cats.” Hilarious though this may be among 12-year-olds, it is annoying to people using Wikipedia for general study and it is disturbing when such vandalism is committed by 35-year-old libertarians intent on giving coal mine owners and anti-environmentalists failed reputations.

Wet poo was just the beginning of the vandalism crudely intercalated within the structure of the acid rain wiki page. If you read Wilson and Likens’ PLOS paper about wiki-graffiti, you will find some of the more vulgar comments that were inserted. As a result of their irritation with the ignorant science-bashers, Wilson and Likens decided to investigate the level of conflict played out on various other contentious science-related Wikipedia pages. These include global warming, evolution, and continental drift. I would have chosen plate tectonics instead of drift, but the phrase ‘continental drift’ attracts less science-worthy editors – which was perhaps helpful to Wilson and Likens’ study. They wanted to see how many nuisance (non-science) edits Wikipedia has been imbibing. Quite a few, it turns out.

In order to attempt to quantify the level of conflict among editors of Wiki pages, the researchers counted the size and number of edits on the potentially contentious pages for the period 2003 through 2012. We may assume that larger edits (over 100 words) likely represent disagreements or insertions of content while smaller edits (fewer than 50 words) probably reflect grammar and spelling corrections and minor additions such as details or references supporting or opposing existing theses. They found that evolution received an average of  9 edits per week with 142 words changed per day. Global warming was edited 13 times per week with 111 words changed daily, on average. Our favourite – continental drift – experienced just 2 edits per week with an average of 24 words changed per day.

Wiki Stats from Wilson & Likens - full description is here.

Wiki Stats from Wilson & Likens – full description is here.

What about plate tectonics? I have not run the exhaustive statistics that the PLOS paper’s authors employed. But I have taken a quick look and compared continental drift with plate tectonics. From January 1, 2015 until today, there have been just 21 non-robotic (and non-sequential edits by the same editor) changes to the plate tectonics wiki entry. Meanwhile, continental drift has seen 118 edits that were not conducted by robots or sequential editors during 2015.   [Wiki bots tend to fix grammar, formatting, vulgarity vandalism, and unsourced materials. Sequential editors are the same person, repeatedly changing and saving and changing and saving again. The bots were not counted as they likely don’t have personalities and are not engaged in flame wars while the sequential editors are counted as a single edit undergoing frequent revisions.]

Fixing the internet.(Credit: xkcd.com)

Fixing the internet.
(Credit: xkcd.com)

Plate tectonics, 21. Continental drift, 118. Those are the total number of actual human-invoked edits since January first.  I was intrigued by the big difference. One thing that immediately jumps out to me, a casual viewer, is that roughly half of the continental drift editors had IP identifiers – they were not editing under registered user names and had not logged onto real accounts. (On the other hand, none of the plate tectonics edits were made behind the guise of an IP ID.)

There may be many reasons edits are conducted without logging on, but such edits should be viewed with suspicion. One example is IP (registered in Colombia, South America) which has been used only once for Wikipedia editing and includes the following vandalism on the continental drift page:  “ONE REASON THEY MOVE … the continents get boried of being in the same place so they move.” Well done, Another user, IP (registered in the USA) decided continental drift could use some porn references. These were undone within seconds by a computer algorithm named ClueBot.

I expected to find a number of tin-hat edits claiming that continental drift is a general fallacy and that such things as moving continents don’t happen on a flat Earth. I was happy to see that no such edits had been attempted among the several dozen entries I reviewed. My general conclusions are 1) topics with a more scientific-sounding title (plate tectonics as opposed to continental drift) receive more scholarly edits; and, 2) most irresponsible edits on the Earth science pages are easily recognized as vandalism.

I learned something else from the Wikipedia statistics compiled by Wilson and Likens: Continental drift is not very popular – and plate tectonics even less so. During the 9-year period researched, drift received about 1300 daily page views. The real action is evolution (6260 daily views) and global warming (15,550). My blog – the one you are reading right now – might be more popular if I had chosen to study and write about biology or the atmosphere instead of The Earth. Alas, I’ll continue my wayward path. And I appreciate your company on this journey.

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Florida’s Newest Sinkholes

Florida's new sinkhole. Engineers are filling it with water to stabilize it.

One of Florida’s new sinkholes.
Engineers are stabilizing it with water.

Smack-dab in the middle of Florida is a farming community called Groveland. It is hard to get more central than this central Florida town.  Groveland rides high on Florida’s limestone spine, a slight rise that puts the center of the state mildly above sea level. The limestone backbone, hidden under clay and sand, is riddled with caves and caverns. These aren’t usually visible from the surface, but they are vulnerable to collapse. On Sunday, three days ago, the lower than usual water table weakened the isostastic pressure holding up the roof of one such cave. The ceiling fell and a 20-metre-deep hole suddenly opened. Luckily, homes were spared, though part of a driveway was swallowed by the earth below.

Sinkholes mar the landscape around Florida like chicken pox on an unvaccinated third-grader. This aerial view shows about 25 circular sinkholes that are over 100 metres in diameter. The largest approaches 500 metres. There are many more sinkholes which are smaller than 100 metres. (The one being celebrated at the corner of East Waldo Street and Iowa Avenue in Groveland is just 15 metres in diameter). Smaller sinkholes have largely been filled in by natural erosion – even in the aerial image below you can see circular swamps and depressions which were likely once small lakes.  By the way, this image covers about 12 square kilometres, of which ten percent is presently water-filled sinkholes.

South Lake County's circular lakes. Most likely were sinkholes that opened centuries ago. Groveland is the town near the top of the map.

South Lake County’s circular lakes. Most of them were likely sinkholes that opened centuries ago.
Groveland is the town near the top of the map.

I lived in this part of Florida for ten years. Groveland was my postal address, though my turf was seven kilometres south of town. It was the 1970s and early 80s. I knew about sinkholes, realized their danger, but spent almost no time thinking about them. Having a sinkhole suck up your home (and maybe your life) seemed less likely than being struck by a truck, a lightning bolt, or a water moccasin.

After a big one swallowed an Orlando house when I lived nearby, I asked a grove owner about the chances of his trees disappearing into a sinkhole one night. He looked at me as if I were speaking in tongues. “No, no chance,” he said. And I suspect people who are still living in the area are thinking about this Sunday’s sinkhole the same way. A grand nuisance, but no one was hurt, little damage was done, and school/work began pretty much as usual on Monday morning.

Monday's U of South Florida resident sinkhole

Monday’s University of South Florida campus sinkhole. Just a meter wide, but twenty metres deep.

The University of South Florida (USF) has a list of 101 sinkholes which opened in Lake County during the 30 years of 1976-2006. There were likely more, but the list gives a sense for the frequency of these events. The USF has similar lists for sinkholes across other parts of Florida, but on Monday they found they didn’t need to travel far to find a new one to examine. Florida’s latest sinkhole – a tiny metre across but 6 metres deep – appeared right on the Tampa campus.

Tampa's killer sinkhole that destroyed a home and swallowed a resident in 2013. It opened again last week.

Tampa’s killer sinkhole that destroyed a home and swallowed a resident in 2013. It opened again last week.

The Tampa area is a hotspot for sink- holes. In February 2013, one formed under the bedroom of Jeff Bush in Tampa’s Seffner suburb. Bush had just gone to bed. In a few minutes, he screamed for help. His brother Jeremy ran to see that Jeff Bush and most of his bedroom had disappeared.  The young man’s remains were never recovered.  Last week, on Wednesday, a 6-metre-wide sinkhole opened again at the same spot.  After the initial sinkhole formed two years ago, the county bought the property and a neighbouring home to prevent another disaster. It reopened, but the county does not expect it to grow larger.

To prevent deaths and dissuade developments atop potential sinkholes, predictive tools would be useful. You would be correct to place money on a sinkhole reopening where one might have existed in the past. As we’ve just seen, the killer in Tampa opened again last week. Even the Groveland sinkhole that led this story is a revival of a smaller one that struck the same spot 40 years ago.

Florida has more sinkholes than any other state and they can strike almost anywhere in the state. It just takes the right combination of near-surface carbonate rocks (which are fairly ubiquitous) and disturbances in those limestone and dolostones. Florida’s shallow ground water is usually slightly acidic. As it seeps below the surface, it eats away at the carbonates, forming water-filled caves. The resulting karst topography includes unexpected fresh-water springs, disappearing streams, caves, and sudden sinkholes. The underground erosion can be exacerbated by droughts followed by heavy rainfall or by excavation for buildings and pumping of irrigation water.

Pumping water can be especially problematic. Without Florida’s groundwater, a lot of farming wouldn’t see its next harvest. On the other hand, the shallow underground pores, vugs, and caves are sometimes depleted with unexpected consequences. For example, in the winter of 2011, a young lady living near Plant City left her back door and fell through a freshly opened sinkhole, a deep cavity less than a meter in diameter. She had her cell phone in her hand, called the emergency line and was rescued. The sinkhole developed because local farmers were pumping water to protect winter strawberries from frost. The water table fell fifteen metres and the aquifer couldn’t recover quickly enough – hundreds of private wells ran dry. Because the pumping suddenly made the subsurface cavities hollow, one hundred forty sinkholes appeared within days. In addition to farm irrigation and emergency anti-frost spraying, Florida’s growing population and domestic water consumption add to the problem of drained aquifers and resulting sinkholes.

Typical residual InSAR data showing deviation in elevation from previous recordings.

Typical residual InSAR data showing deviation in elevation from previous recordings.

The hope of predicting the next sinkhole now rests on NASA technology.   Satellites equipped with Interferometric Synthetic Aperture Radar (InSAR) may detect changes in ground elevations over time. Such changes may indicate an area’s vulnerability for sinkholes – sometimes a few centimetres of subsidence occurs before the ground collapses. InSAR can measure subtle deformations. This is done by comparing sequential radar surveys, searching for changes. At this moment, the technology is so new that these surveys are still in the planning stage. It might not even work as a predictor. Unfortunately, not every sinkhole is preceded by subsidence. Some simply pop open, swallowing the surface.

Not only are they sudden and (so far) unpredictable, you can’t be totally safe anywhere in the state, though some areas are riskier than others. If your retirement dream includes Florida, you can’t pick a safely non-sinkhole homestead. However, if we consider that about ten percent of the more active areas has been sunk sometime in the past 10,000 years, then you might assume that there is about a one percent chance that your property will experience a sinkhole in the next thousand years. So, you are reasonably safe – but you should probably avoid any real estate that has had a recently patched sinkhole.

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