"Japan has the most advanced earthquake early-warning system in the world. A nationwide online system launched in 2007, it detects tremors, calculates an earthquake's epicenter and sends out brief warnings from its 1,000-plus seismographs scattered throughout the country, one of the most earthquake-prone nations on the planet.



"P-waves are the first evidence of a quake (P is for primary), and have fast, short wavelengths and do little damage. These are followed usually several seconds later by the destructive S-waves (S is for secondary) with longer wavelengths. These snakelike seismic waves, feared as earth dragons in ancient China and Japan, are the gut-wrenching movements that crush buildings and create landslides. "The good news is that P-waves always come before S-waves so you can prepare yourself," says Oki. "All Japanese are taught to sense the difference when they experience a quake." It's clear this is not just nationally endorsed education, but a means for survival."

A new feature has shown up in the still-to-be-released iOS 5: an early warning system for earthquakes tied to Japan's earthquake-early-detection service.Japan has the most advanced earthquake early-warning system in the world. Just a week after the Sendai earthquake and tsunami, which the country is still recovering from, Time Magazine profiled the system . The report said:The new notification setting can be enabled or disabled from within an iPhone’s settings on Japanese devices.Third-party iOS apps for earthquake detection like Yurekuru Call have already existed for some time, and many Japanese phones already have this as a core feature, so Apple is just joining the club.One potential problem is that the setting could adversely affect iDevice battery life. The above message in Japanese basically warns that the new feature may reduce the device's battery life as it is always connected to Japan ’s warning system.Aside from Japan, other countries, such as Mexico, also have natural disaster early-warning systems in place. California is set to roll out its own early-detection system sometime around 2013.Although Android does not have this functionality in the core of the platform (yet), there is a version of the same Yurekuru Call app available in the Android Market.