The upcoming iPhone 5 is apparently going to come equipped with an earthquake alert application.
As this post by BBC News details, Japan already has an early-notice system for earthquake alerts, but this iPhone notification setting is obviously a great idea.
For SMS, the system works by sending out a mass cell broadcast (SMS-CB) to all handsets in a designated area.
3G cellphones are compelled by Japanese law to include SMS-CB technology. However, many foreign-made phones do not currently support it.
Read more at 9 to 5 Mac.