But even more confounding is the curious case of trying to figure out mass “per volume” at very low concentrations.
For instance, we know that sea water is salty, but just how “salty” is it?In scientific terms, it’s 35 parts per thousand (ppt) “salty.”
The recipe in your kitchen would call for adding 26 teaspoons of salt per gallon of water. (Easy enough, I have both.)
How about parts per million (ppm)?
Now we’re getting dilute.
The recipe calls for adding 1 teaspoon to sauce pan the size of 31 rain barrels (at 42.5 gallons per barrel).
Can anything that dilute harm us?
Nitrate levels at a concentration of 10 ppm is cause for alarm for one. (That's one reason why people buy bottled water instead.)
How about parts per billion (ppb)?
(Now this will test how well equipped we are in our kitchen!)
This recipe calls for adding 1 teaspoon (good we already have that one) to a lobster pot the size of 2 Olympic swimming pools.
Can you even measure something that dilute?In the Everglades, total phosphorus in concentrations above 10 ppb is considered a pollutant.
As confusing as all this seems (even to me), I’m glad to know that I am at least semi-well equipped as a hydrologist (going out into the world) if I have nothing else but a “teaspoon” in my hydrologic satchel.
It’s better than the alternative:
Carrying the water!
5 comments:
They just wouldn't listen to reason. All they saw was dollar signs. Now our dollars have to undo as much of the damage as is humanly possible.
Samantha
Are you scared to be alone at home need security
You can create salty water with a teaspoon, but I'll bet it's a little harder to measure the salt unless you wait for evaporation!
The Great Salt Lake is our closest salty water... and it has recently been determined to be higher in mercury than any other body of water in the US. In case you were considering it, don't eat anything that's been hanging around our Utah "ocean."
I read that report, but didn't catch that Great Salt Lake was top on the list. Someday I'd like to see that lake. It makes an interesting comparison to Lake Okeechobee, which by the way is much closer to salt water (25 miles from the Atlantic and 50 miles from the Gulf of Mexico) and only 14 ft above sea level.
The Great Salt Lake is +4000 ft above sea level and 500 miles to the Pacific.
The one thing they do have in common is depth: both are shallow, with average depths below 20 ft.
Fascinating! I never realized that Nitrate levels could affect life so much.
This is very helpful to me! I often have students who want to know what parts per million/billion means exactly. This is a great way to help children understand it! Thanks!
Post a Comment