Bad Geology

One of the blogs I appreciate the most on the internet is Phil Plait's Bad Astronomy blog. Well, today is the first installment of "Bad Geology". Today's example comes to us via Boing Boing, a tech / pop culture site. The picture given at left shows something labeled an "artesian aquifer" at depth. First of all, an aquifer is not an underground swimming pool. Most underground water is actually stored in the pore spaces between grains of rock (think wet sand). Artesian, by the way, means that you don't have to pump to get the water out. Often aquifers are floored by impermeable layers, sometimes called "aquitards" in hydrology. But parhaps in today's litigious society, any use of a word with "tard" in it isn't the wisest advertising choice. Anyway, aquifers often have an impermeable layer below them that allows rainwater filtering through the system to collect in the aquifer (such an aquifer is also known as a perched aquifer). But one has to ask why the impermeabe rock layer is shown surrounding the aquifer? How did the water get in there to begin with?

Final grade: F+ (the plus is for using nice colors).