One time when I was a teenager we had a quake in New Hampshire that was around a 4.5. It only lasted about 10 seconds–we’re not exactly on a fault line. I was more or less terrified when I was in Florida and Hurricane Wilma hit with 110-mile-an-hour gusts and fake terra cotta shit was blowing off the roof and smashing into cars in the parking lot. But at least you can plan for hurricanes, not that anyone in Florida bothers. At least it was cool that afternoon. I had a great run that day except for having to dodge live wires on the ground. I don’t miss that place. I just wonder what will happen first–a Cat 3/4/5 windstorm that wrecks Miami or a massive quake that destroys San Francisco/Oakland. If I had to pick I’d rather see the hurricane but my friend’s parents live in Fort Lauderdale and I know they wouldn’t leave and it would suck if her house got flattened.

The Richter scale is logarithmic, meaning that a quake of magnitude 7.5 is 10 times as powerful as a 6.5 and 100 times as powerful as a 5.5. The Haiti quake was a 7.0, so if I did my calculations right, the Chile quake was 63 times as powerful.

Just to be clear, “powerful” here refers to amplitude of ground motion, rather than energy release, which you correctly reference in the next sentence.

The media has gotten better about referring to the magnitude scale, rather than the Richter scale, but it still crops up here and there. At least they now (mostly) say tsunami, rather than tidal wave.

I guess the part I wanted to get right was the math–I don’t know that most people are aware that a lot of metrics (e.g., sonic pressure, stellar magnitude) involve log or semi-log scales. Then again maybe most don’t care. You must be some kind of geoscience nut, which means you like running up mountains and staircases.

The Richter scale was developed for quantifying medium sized, SoCal quakes. The moment magnitude scale is the more common method for quantifying the amount of energy released during a quake. A correct title would be “What a magnitude 8.8 earthquake means”

…regardless, a massive quake.