Tag Archives: southern california

How Much Bigger is a 4.7 Earthquake Than a 4.4? Twice As Big.

OMG it’s a math post!

Yesterday we had an earthquake here in SoCal.  It was the most dramatic one I’ve been here for, by a long shot, and my friends have all said the same — probably because we all live near the epicenter and it was quite a shallow quake.

It turned out the earthquake was only a 4.4 — a bit of a disappointing number after what we had felt!  Anyway, it was first reported in as a 4.7, and then revised to a 4.4, and someone retweeted this tweet:

Well, yeah.  But that doesn’t really tell us anything, does it?  It’s a difference of .3 on the Richter scale, but the Richter scale is logarithmic, and we silly humans aren’t used to thinking in logarithms unless we’re astronomers.  So how much bigger IS a 4.7 than a 4.4?

(cut for math)

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