The 2011 Great East Japan Earthquake largely sank the ground level of the Pacific coast of Tohoku region and northern part of Kanto region. The risk of the submergence and flood in these regions has become larger than before the 2011 Great East Japan Earthquake.

Therefore, it is necessary to pay special attention to the tide level and to prepare for the submergence and flood in these regions, especially during the spring tide, when the flood tide level becomes higher than usual.

JMA will alert the region where the ground level largely sank by issuing the Storm surge Advisory.

Special attention should be paid to the tide level around spring tides (until the end of April);

• from 18 to 26 March, 2011
• from 1 to 11 April, 2011
• from 16 to 24 April, 2011