How are logarithms used in the pH scale and richter scale?
Jul 29, 2010
in
Earthquake Questions
I wondering what the math behind it is.
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3 comments
Paul on July 29, 2010 at 10:49 pm
They’re also used in sound intensity as well(decibels and such)
Here’s the skinny: sound intensity/energy intensity/ acidity all increase by multiplying again by 10 – so it’s just easier to compare the exponents(which is what logs do) than comparing big numbers.
It’s easier to say an earthquake of richter scale 6 than an earthquake with something times 10^6 amount of energy/meter squared.
Courtney C on July 29, 2010 at 10:49 pm
each number up is ten times more powerful. This the same way with pH.
Mark on July 29, 2010 at 10:49 pm
For example, a Hydrogen ion concentration of 1/10² is said to be a pH of 2. (Because 2 is the exponent or logarithm).
Another way of writing 1/10² is
10 raised to negative two.
So you’ll hear some say that pH is the negative logarithm of the H ion concentration. They’re too busy keying calculators to know what they’re talking about.