EEW Earthquake Early Warning (False Alarm) 20130808 M7.8 Nara Japan скачать в хорошем качестве

EEW Earthquake Early Warning (False Alarm) 20130808 M7.8 Nara Japan

Japan Meteorological Agency Issues False Alarm of “Maximum Intensity 7” in Earthquake Early Warning Trouble with Undersea Seismometer Cited as Cause On the evening of the 8th, the Japan Meteorological Agency predicted an earthquake with an intensity of 6 lower to 7 would occur in Nara Prefecture and Osaka Prefecture, issuing an earthquake early warning for 34 prefectures from the Kanto region to Kyushu. However, no region observed an intensity of 1 or higher, which is perceptible to humans. The agency acknowledged the alert was erroneous, explaining that an electrical signal malfunction in a submarine seismometer off the coast of Mie Prefecture caused the false alarm. According to the agency, at 4:56 PM that day, an earthquake with an estimated magnitude (M) of 2.3 occurred with its epicenter in northern Wakayama Prefecture. At almost the same time, the electrical signal transmitted from a submarine seismometer installed off the southeast coast of Mie Prefecture was interrupted. This disruption caused an error in the calculations, leading to an overestimation of the shaking. As a result, the agency erroneously issued an alert stating, “An earthquake with a magnitude of 7.8 has occurred with its epicenter in Nara Prefecture.” (Nikkei) 20130808 NHK BS1 BS NEWS