January 2012
How to Convey the Unexpected
Hidehiko Fukunaga
At the great east Japan earthquake, Japan was hit by a massive earthquake and tsunami that were far beyond the government anticipation. Initially, the Japan Meteorological Agency (JMA) misjudged the quake magnitude that lead to underestimation of the height of initial wave. This article examines when and how JMA, local governments in the afflicted areas, and mews media recognized and reported the fact that the actual situation was much more serious than expected and forecast. Among them, regarding local government, the author compared two types of municipalities with different past tsunami experiences, in order to examine how unexpected crises should be communicated.
When the first major tsunami warning was issued, JMA forecast that the height of approaching tsunami would be 3 meter in Iwate Prefecture, 6 meter in Miyagi Prefecture, and 3 meter in Fukushima Prefecture. However, the agency noticed that the GPS wave sensor located off the coast of Kamaishi was showing the sudden elevation of offshore sea level and raised the estimated height of tsunami.
The disaster countermeasures office in Kamaishi City, Iwate Prefecture intuitively knew the seriousness of the event from the type of shake and its length and alerted the residence through the disaster management radio system that the initial wave would not just “3 meter” but “3 meter and higher.” Afterwards, however, when the height was raised to 6 meter, the municipality was not informed of the fact that the change of the height was due to the sudden elevation of the sea level off Kamaishi. Consequently, the city soon stopped announcing the height because they found the information unclear. Meanwhile in Yamamoto Town of Miyagi Prefecture, many officers of the town’s disaster countermeasures office or the Watari Fire Fighting Head Office did not know the unexpected level of crisis until they say the giant wave rushing to their place. The same phrase was used for the evacuating warming even after the expected tsunami height had been altered from 6 meter to 10 meter.
What made NHK News Department clearly recognize the gravity of the situation was the live images fed via the robot camera. After that, NHK’s reports focused on updated information and live images of the mega tsunami. Although the first information update should have placed the first priority on information about the expected tidal height in Iwate and Miyagi Prefectures because the time was pressing, the order of telegraph sent by JMA to news media was according to the areas on which warnings and advisories were updated or altered.
Having examined the above, the author points out that in order to transfer the information on a situation which is beyond the expectation or forecasts, it is necessary to (1) actively utilize the actual readouts of GPS wave sensors or undersea water pressure gauges, (2) determine priorities of updated information and convey the information in order of significance, and (3) consider the regional difference in sensitivity to tsunami disaster even if these areas are located in a same forecast zone.