Kids Web Japan

The Japan Meteorological Agency monitors tsunamis and earthquakes using the EPOS system. (Japan Meteorological Agency)

As a result of this incident, it was decided to drastically remake the two earthquake-related software programs that the Japan Meteorological Agency used: the Earthquake Phenomena Observation System and the Earthquake and Tsunami Observation System.

Intent on getting the better of tsunamis, the earthquake and tsunami experts at the Meteorological Agency worked with university researchers to create a database for each of 600 places throughout Japan by simulating 100,000 tsunami cases. When an earthquake occurs and its epicenter and magnitude are determined, the closest simulation data is instantly searched out. If the analysis shows there is a possibility of a tsunami, alerts are issued along with the approximate time of arrival for each of 66 regions across Japan. A "large tsunami warning" is given out if the tsunami is expected to reach a height of more than 3-10 m, a "tsunami warning" if it is expected to be 1-2 m high, and a "tsunami advisory" if it is expected to be 50 cm or lower. Before the improved systems were developed, the number of regions used to be just 18. Moreover, the alerts were improved so that they included not only one of the three alert levels, but also a forecast of how high the tsunami will be. This groundbreaking new system was completed in 1999. The forecast time was shortened to between 3 and 5 minutes.