Apocalyptic Phenomena

Greetings from New Haven, Missouri!

We are enjoying the 13 year Cicada bloom, a rare honor I am encouraged to appreciate by our hosts. The humming rises and falls all day long and into the night. When the cicadas come out to mate they are not bashful about it. I viewed them as a nuisance until I learned that this is a bona fide episodic event in nature. Like Haley's Comet or a 100 year flood, you can't just go find a swarm of cicadas any time you wish. These events give us meaning and a way to mark the passage of time. (We met three years before the Cicada bloom of 92 and so forth.)

What other natural events meet this criteria and how are they interpreted now and how were they viewed in the past?

Please tell us.

Juancho