From 5.9 to 5.4

Posted on July 11, 2010 in Earthquakes

The USGS errs on the side of excess when it first estimates the power of an [[earthquake]]. At least I have never seen it publish a number and then increase it after reports from all its stations arrive. So it was for its first call on the magnitude of the earthquake that rumbled across Southern California last Wednesday. The first number was 5.9 followed by 5.7 and resting, at last, on 5.4.

In reflection, the way that the USGS comes up with its [[Richter scale]] estimations is the opposite of what psychiatrists do when they start you on a medication. The latter starts you on a low dose, then works you up to a higher one.

In my diary, I made this note:

Moderate earthquake. I heard it, felt the slowed undulations. It segued in, then slipped away. Over in about 20 seconds. The animals didn’t have enough time to panic, though Fiona would not go into the loft until dinner time. (The stomach always wins out.)

This was no Loma Prieta. As soon as it hit, I tweeted “EARTHQUAKE!”. As my API client refreshed, half a dozen or so similar exclamations twittered into existence, each, no doubt, concerned that he or she was the first to publish the fact.