Thursday, August 16, 2018

Contour Intervals for Dummies, the Rewrite

isopycnal map Texas rain
This contour map isn't a topographic map...
The staffer who was being punished with "broken links" duty earlier this week caught the nice people at Leaf Group running old posts through their rewrite process. Whether it's to improve the quality or just to "freshen" the content, Leaf has a small stable of contributors going over old posts and rewriting them. Every once in a while, they touch on one of our old DotD nominees, The problem is that the rewrite isn't necessarily any better than the original. That's what happened when Karen G. Blaettler took on "How to Calculate Contour Intervals"¹ for Sciencing.com.

Blaettler's assignment was, apparently, to improve on the job Soren Bagley had performed back in 2009 for eHow.com. We'd like to think that Karen, who claims to have worked as a geologist for a while (LinkedIn says 6 years working for a geotechnical engineering firm, her bio says 10) would do a better job than a film school grad, but nope...

Like Bagley, Blaettler immediately zeroed in on topographic maps:
"Topographic maps show the contours, or shape, of the land. Every map has a legend that explains the different colors and patterns. Normally contour lines will be brown and waterways will be blue..."
We have to admit that we've gotten tired of all the references to topographic maps when the scientifically ignorant (the woman's a friggin' SCIENCE teacher!!!!!) see the words "contour line." Never mind that, though. Blaettler used most of her page space to explain how to read topographic contours, drawing heavily on the text in many elementary earth science books. She also compounded Bagley's idiocy about not reading the friggin' legend to learn the contour interval by explaining that,
"A map's legend usually identifies the contour interval on the map, but sometimes only part of a map is available."
To which we say, "Snort!"

     While Blaettler's process for determining an unknown contour interval is (overly wordy, but more or less) correct, that's not the point of her Dumbass of the Day award. The point is that she does not serve science by using at least half of her post to explain how to use topographic maps. Instead, Karen G. would have been a better teacher if she had mentioned that contour lines can be used to depict any numerical data for which you have geographic information.

To that end, we suggest that Blaettler, her content editor, and all the folks at Leaf Group look up the following words: isoline, isochron, isopach, isobar, isopycnal, isobath, isotherm, isoechoic, isohaline, isotach, isogauss... just about any word with the prefix "iso-." Heck, Charles Darwin's cousin Francis Galton once compiled and contoured a (subjective) "Beauty Map of England"; so yes, anything!


¹ Lo and behold, Leaf Group sent Karen's version to yet another member of the rewrite team... It wasn't even there long enough to be captured by archive.org. So sad...   
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