Yurekuru Call Earthquake Early Warning App

Earthquakes are a regular part of life in Japan since it is located on the “Ring of Fire“. There are shakes from minor earthquakes at least daily somewhere in Japan, with thousands of earthquakes each year. Japan has had three very large earthquakes in the 20th century. The oldest being the 1923 Great Kanto Earthquake (7.9 Magnitude), the next was the Great Hanshin Earthquake in 1995 (6.9), and the most recent was the Tohoku Earthquake (9.1) and Tsunami in 2011. As a result of the major destruction caused by some of these earthquakes, the Japan Meteorological Agency developed an early warning system for earthquakes. The JMA also developed Japan’s own earthquake seismic intensity scale, known as the shindo seismic scale. In this scale, the intensity of an earthquake is measured by the amount of ground movement, or shaking, that is measured by ground motion accelerometers. The shindo scale is expressed with a number between 1 and 7, with 7 representing the most amount of shaking.

With the use of the Earthquake Early Warning System, the Japanese Government and various companies can provide early warning of large earthquakes. Television warning notices are usually shown more than a few minutes after the fact. But, cellphones are now used to provide early notice of coming earthquakes. Japanese cellphones automatically provide the warnings through the service provider. But now there are many earthquake early warning applications that you can download in order to be warned of incoming shaking. Of course, this doesn’t really matter if you are really close to the epicenter, as you won’t get much warning. The warning system works by measuring P-waves, which travel faster than the more noticeable S-waves.

I have a Japanese phone and Softbank service, and I will only receive earthquake early warnings if the earthquake is really close. Luckily, we don’t have that many in the Hiroshima area, so I don’t even recall receiving an earthquake warning on my phone directly. I have seen them from the apps that I have installed though. If you are an Android user, you may want to check out “Yurekuru Call” on the Google Play store. If you are on an iPhone, they have recently updated the app and the reviews are not good. Mainly, English is not available any longer on the iOS version now called “PREP“.

I really like the Yurekuru Call earthquake early warning app because it really does give early warnings. For instance, about 2 weeks ago there was a 4.9 magnitude in Ehime Prefecture. Yurekuru Call sent me a warning that an earthquake of shindo 2 would be coming in 9 seconds. Sure enough, some seconds later I felt the light shaking from the earthquake. I don’t recall if it was actually about 9 seconds, but I would say it was fairly close.

In addition to the early warnings from the Yurekuru Call earthquake early warning app, you can record in the app how much shaking you felt in your area. Soon you’ll see new indications popping up of other people that have recorded the intensity that they felt, along with comments that you can make. The app is free, but that means that you will not experience the full functions of the app. The free version is still very useful. You can record the shaking that you felt in the free version, but the earthquake history listing is rather short.But, for recent earthquakes, you can click on the earthquake in the history list and see a map of the area and the shaking intensity as reported by other people. The app also includes earthquake safety tips.

If you’d like to see something really interesting, go to Japan Quake Map and above the map you can click a link that will show you all earthquakes recorded in Japan since the March 11, 2011 earthquake in Tohoku. After the magnitude 9 at 14:46, it just starts going wild with all the aftershocks. Below is a small snapshot of a part of the site.