The seventh largest quake ever occurred this week. The eighth largest quake occurred last year. The third largest quake occurred in 2004. Add to this hurricanes and floods, and it seems like natural disasters are on the rise.

Nouriel Roubini agrees. He tweeted yesterday: "Rising rate of Black Swan/Tail Risk/Unknown Unknowns events: repeated natural disasters, Japan nuclear meltdown risk, Middle East turmoil"

Now here's a chart that confirms the theory, from University of Hawaii economist Ilan Noy.

Noy says the increasing prevalence of disasters may be driven by improved reporting of mild events.

Even so, we're living in a world where people read about disasters frequently, and everyone is perpetually freaked out.