Words’ worth IV

Back on the first incarnation of this blog, I occasionally posted about words that bugged me. A few more have piled up since then, so here we go with the latest consideration of “words’ worth”…

First off, let’s consider the use of “outcrops” as a verb. This came up recently on this blog when commenter Tom Skaug pointed out that I was incorrectly using that term. He’s right of course, and has the dictionary citations to prove it. Technically, we should say that a particular rock unit “crops out” on a hillside. Mea culpa. I appreciate the correction. That being said, I know a lot of geologists who speak as sloppily as I write. Using “outcrop” as a verb is reasonably common slang in my circles.

Next, let’s consider some plural words. When reviewing an article recently, I saw the words “maximums” and “minimums” written out by a science writer. I suggested to the editor that these should be “minima and maxima” instead. The editor countered that real people (i.e., non-scientists) don’t speak that way, and that the accepted parlance among the general public is just to tack an “s” on the end of a word to make it plural. However, in Latin, the language that gives us these words, the plural would end with the addition of an “a.” When you look it up in a dictionary, both plural forms are listed. To add insult to injury, my computer’s automatic spell-checker function is putting the red zigzag under my correct Latin versions, and NOT underlining the “-s” versions. I’m beset on all sides!  Still, to me, “minimums” sounds clunky and clumsy, while “minima” is elegant and sleek, like a well-designed scientific instrument.

Okay, here’s another one. Occasionally, graffiti appear on the walls of the bathrooms here at the community college where I teach. When I spot a new scrawl, I write an e-mail to the cleaning staff alerting them to the vandalism. But what do I do when there’s just one little new jotting? Graffiti are plural; the correct singular of this Italian word is “graffito.” But that sounds vaguely ridiculous, right? “Dear Cleaning Staff, There is a new graffito in the men’s bathroom on the east side of the Shuler Building’s second floor.” I feel silly, and maybe a little pompous, if I use the correct singular form of this word. Anybody else have a word like that, where they know how to use it correctly, but they use it incorrectly on purpose for the ease of communication? (…Or possibly to avoid offending someone?)

Along similar lines, data are plural, while datum is singular. Most scientists are comfortable discussing a single datum, and are careful to only use “data” when there’s more than one chunk of information being discussed. But the general public doesn’t parse this distinction as finely. You’ll see “data” used to refer to what really is a lone datum.

Natural gas – I was thinking about this one while driving into work the other day, and the radio newspeople were talking about that big explosion a few weeks ago in San Bruno, California. It got me thinking about the term “natural gas.” What a dumb, non-descriptive term. I mean, do we ever refer to “natural liquid” or “natural solid?” Natural gas is annoyingly non-specific. I get it: it’s a cocktail of different gases, mostly methane, with a dash of ethane and maybe a few other volatile compounds too. If it were pure methane, we would call it “methane,” but it’s often not pure. It’s a mixture. So we can’t call it just “methane,” because that wouldn’t be accurate. The mixture occurs naturally, so we call it natural gas. We trade specificity for meaningless but accurate inclusiveness. Blech. The role of “natural gas” as a fossil fuel is ascendant; we’re going to be talking about it for some time to come. I think we need a better name for the stuff. Suggestions?


EARTH: the biography, by the BBC

Last week, I watched the BBC/National Geographic series “EARTH: The Biography,” hosted by Iain Stewart.

Stewart is a charismatic host, with a thick Scottish accent that cannot disguise his enthusiasm for geology. The five episodes focus on: volcanoes, ice, oceans, atmosphere, and “rare planet.” Overall, I thought the series did an good job covering some of the greatest stories in geology with an emphasis on presenting the latest ideas. Snowball Earth gets screen time, for instance, and the ocean-anoxia hypothesis for the end-Permian extinction, too. They also cover ocean acidification, a topic I feel deserves wider press.

The series is well-produced. Stewart zips all around the globe, and the editors seamlessly incorporate imagery from other BBC series (like Planet Earth) as supporting content where appropriate.

Here are some of the tidbits I gleaned from the show:

Two billion tonnes of the Andes are carried down the Amazon every year (in the form of sediment weathered and eroded off the Andes). Along similar lines, 40 million tonnes of dust from the Sahara Desert are dumped on the Amazon Basin every year. I wonder if the Sahara dust is included in their sediment volume estimates, or whether it is deducted since it’s not of Andean origin. Great statistics regardless.

They tell the story of Joesph Kittenger in the atmosphere episode. He did a skydiving jump from 90 miles up! After free-falling through almost the entire Earth’s atmosphere, this crazy dude lights up a cigarette! Those were the days.

Four million tonnes of the Sun’s mass are converted into energy every second. Whoa.

Humans now move more rock and soil than all natural processes combined. Ergo: Anthropocene.

The Mediterranean Sea loses three times as much water to evaporation than it gains from rivers and rain. Without the Straits of Gibraltar to let in Atlantic water, it will dry up (and it has dried up, multiple times in the past). In illustrating this, Stewart goes into a salt mine beneath Sicily and shows some BEAUTIFUL contorted salt laminae. Worth watching the whole series just for those gorgeous patterns. (here’s one shot)

The footage of Fayetteville Green Lake in New York is excellent — this is a deep lake with pronounced internal stratification of water and not much mixing — the deep parts of the lake have become anoxic and euxinic (enriched in H2S). They illustrate this by diving into it and the water turns PINK. It is presented, of course, as an analogy for one of the leading models for the end-Permian extinction: global ocean euxinia. It is astonishing to see pink water, and enticing to think about, but the show commits a major “fail” when they don’t tell what this substance is, or where it comes from. They describe the water as having “something deadly” in it, and then say it’s a “highly toxic poison,” or “a gas as deadly as cyanide,” but never do they (a) call it hydrogen sulfide, and (b) explain that it comes from certain kinds of bacteria that thrive in low-oxygen waters. Another complaint: they don’t say when the Permian-Triassic extinction occurred, just the same old saw about it being the “greatest” extinction in Earth history, and that it occurred “before the dinosaurs.” The word “Permian” is never used.

I have some other criticisms, too…

The phrase “a blink of an eye, geologically” is used too often. Twice in the first episode alone!

They show an image of a comet moving like a badminton birdie, with the tail pointing back where the comet came from. This isn’t accurate — comet tails point away from the sun (dragged downstream by the solar wind).

At one point, when discussing the history of life on Earth, Stewart suggests that “life needs catastrophes.” I would argue that life has diversified due to catastrophes, but that catastrophes are not necessary for life to continue. In a non-catastrophic situation, life just perpetuates itself and may exhibit increasing specialization or genetic drift within the parameters available in its environment. But “needing” a catastrophe every now and again? Only if diversification of life is the goal — I take issue with this verb.

In another episode, Stewart is describing convection in the mantle, and says that “magma” is moving upwards. This is false: it is hot rock (a solid), less dense than neighboring relatively-cold rock. The “magma” idea for the Earth’s mantle is a popular misconception which Stewart is opting to elide rather than confront.

At another point, in praising the Moon, Stewart suggests that the planet Earth’s climate would have switching between freezing cold and boiling hot if it were not for the Moon’s influence. No explanation is given for this extraordinary claim. He may indeed have a chain of evidence and inference in mind when he says this, but without a robust explanation, this statement comes off as “because scientists say so”: an authoritative statement with no supporting detail which shows how science comes to a particular conclusion. Worse, he then cranks it up with the future fear factor — they go into great detail about how we have determined that the Moon is drifting further away from Earth over time, and then suggests ominously that Earth will then lose its climatic stability. So now we’ve got alarmism too, but again, no explanation of the supposed causative relationship is given.

Overall, it’s an enjoyable series, and I was pleased to have it to watch when I had the flu last week. Check it out, and let me know what you think.

Strath vs. terrace graphic

There is an old Chinese aphorism that “the beginning of wisdom is to call things by their proper names.” One of the naming conventions that tends to trip up NOVA students who hike the Billy Goat Trail with me is the difference between a “terrace” and a “strath.” This morning, I created a graphic that illustrates the difference between these two landforms as I understand it:


Both features are shown in cross-sectional cartoon view. Terraces are cut into alluvium, the unconsolidated sediment deposited by the same river which is now incising. Straths, on the other hand, have the same shape but are etched into bedrock. Another name for straths would be “bedrock terraces.” Straths will sometimes have a thin veneer of alluvium atop them: in my experience along the Billy Goat Trail, this consists of abandoned bedload from older, higher base levels, augmented by lighter-weight flood deposits.

Would anyone with more geomorphological knowledge than me care to qualify / critique / correct my understanding on this terminological issue? Thanks in advance!

UPDATE: Based on Anne’s comments below, I’ve tweaked it a bit: