The 2011 Great East Japan Earthquake ~fourth report~
Activities of Aftershock
The activities of aftershocks of the 2011 Great East Japan Earthquake has been very active.
As of 12:00 JST, 16 March, the aftershocks larger than magnitude 7.0 occurred 3 times, and those larger than 6.0 occurred 48 times. The largest aftershock occurred at 15:25 JST, 11 March (magnitude 7.5).
The aftershocks have occurred in the large area off the coast of Iwate, Miyagi, Fukushima, and Ibaraki Prefectures.
When compared to past cases, the activity of aftershocks is very high.
Outlook of Aftershocks
- Near the epicenter, maximum JMA Seismic Intensity of aftershocks may be 5- or higher.
- A strong aftershock may occur tsunami. Be cautious when a tsunami warning or advisory is issued.
- Estimating from the occurrence of aftershocks so far, the possibility of aftershocks with maximum JMA Seismic Intensity of 5+ or higher is 40% for the 3-day period from 12:00 JST, 16 March, followed by 20% for the 3-day period from 12:00 JST, 19 March to 12:00 JST, 22 March.
Notes on Disaster Prevention
- In the area where strong shaking was observed, keep vigilant to tremors by aftershocks which may cause landslides and house collapses.
- Many places could be dangerous after tsunami and earthquakes. Be cautious and ensure adequate safety on your way back from the evacuation center, by following instructions and directions of the local emergency officers.
- Stay away from coasts when tsunami warnings/advisories are issued.