Tuesday, April 20, 2010

Earthquakes are all around!

Living in San Francisco I have to deal with earthquakes. Even worse, I have to deal with irrational fear mongering claiming such-and-such reason proves the "big one" is imminent. The past month or so has been even worse than normal as the topic has come up often in various conversations. I was curious as to why this was, that is until I turned on the TV (a rare occurrence for me nowadays). Based on news coverage, it seems like everyday there is a new story about a medium-to-large earthquake happening somewhere in the world (and the more impoverished or damaged the area, the more news coverage it gets).

And you know what? They are right, everyday an earthquake ranging between 5.0-8.0 does happen!

The only difference between this year and previous years is the news companies decided to actually report about the earthquakes because that is how they earn money. While covering the tragic earthquake in Haiti this year, news organizations (aka businesses) gained lots of sympathetic viewers. Suddenly, earthquake coverage became a commodity and any time an earthquake happened somewhat close to a susceptible urban area the news organizations made a big deal out of it. Yet 5.0 earthquakes happen almost four times a day, and an earthquake ranging from 6.0 - 9.0 happens roughly once every three days. There aren't more earthquakes happening, there is just more news coverage of the normal amount of earthquakes.

Look at the chart below from the US Geological Survey (the world's expert in earthquake tracking):

Magnitude 2000

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
8.0 to 9.9 1

101 2 1 2 4 0 1 1
7.0 to 7.9 14

151314 14 10 9 14 12 16 5
6.0 to 6.9 146

121127140 141 140 142 178 168 142 67
5.0 to 5.9 1344

122412011203 1515 1693 1712 2074 1768 1754 785

We are roughly 1/3 of the way through the year and the numbers are within the normal limits. What's more, our technology used for finding earthquakes is improving each year so that we are finding more this year that would have be missed in previous years (meaning the older numbers are likely quite lower than the actual number of earthquakes which occurred that year).

Do not assume the amount of news coverage of a topic is an indicator of how much it happens, rarely do the two correlate. The worst example of this was "the summer of the shark" in 2001 when every news channel reported on each attack that occurred that summer. Yet 2001 only had 4 deaths from shark attacks (9 fewer than the year before) and was one of the lowest shark attack years in a decade. But the people's impression was that everyone in the water was risking their life by swimming with rampaging sharks. Twenty times more people died from lightning that year than from sharks, but no one called it the "summer of Zeus' revenge"....

Yes, San Francisco is going to be hit by an earthquake in the future. It sits near many faults and the law of averages shows that it is going to happen. An 8.2 magnitude earthquake hit in 1906, a 5.1 in 1957, a 7.1 magnitude in 1989, and who knows when the next one will happen? All we can do is prepare ourselves and refine technology that will give us an early warning. All the fear mongering by the news does nothing but make people irrational.

On a side note, given a large enough timeline nearly every city in the country is in danger of a natural disaster. Three major earthquakes have hit San Francisco since 1906, but that doesn't make it a more dangerous city when it comes to natural disasters. If you look at any city over the last 100 years you will find they have also been flooded by torrential rains, flattened by tornadoes/hurricanes, destroyed by high winds, trapped under blizzards and ice storms, ravaged by heat waves and dust storms, burnt by out-of-control fires, etc. Go to your city's archives and you will likely find it has been hit by far more natural disasters in the last 100 years than San Francisco has. So if you want to be scared, then watch out because your city is next!!!

okay, that's enough fear mongering from me in one post)

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