#723: Seismic Waves explain

When an earthquake hits, people flood the internet with posts about it-some within 20 or 30 seconds.

[A room with a desk, chair, and computer are shaking. The person in it is on his phone, using Twitter.]

RobM163 Huge earthquake here!

Damaging seismic waves travel at 3-5km/s. Fiber signals move at ~200,000km/s.

(minus network lag)

This means when the seismic waves are about 100km out, they begin to be overtaken by the waves of posts ABOUT them.

[There is a geographical border on a map; the front edge of the wave of the quake is shown, with the front edge of the wave of tweets surpassing it.]

People outside this radius may get word of the quake via Twitter, IRC, or SMS before the shaking hits.

[Megan and Cueball are standing, holding cell phones. Megan is looking at hers.]

Megan: Whoa! Earthquake!

Sadly, a Twitterer’s first instinct is not to find shelter.

Megan and Cueball (on phones): RT @RobM163 Huge earthquake here!