Web site of 防災科学技術研究所;National Research Institute for Earth Science and Disaster Prevention=NIED/ Although none of web site is available for basis of 400 times in a day, but 400 times is well told and well assumable number with this data. ↑ 気象庁震度階級（明治17年～昭和23年） Archived 2009-04-22 at the Wayback Machine. in Japanese ↑ 震度 Archived 2008-06-18 at the Wayback Machine. in Japanese ↑ Calculation method of seismic intensity (Japanese) Archived 2008-09-17 at the Wayback Machine. ↑ "Seismic intensity and acceleration (Japanese)". Archived from the original on 2008-07-05. ↑ Agency, 気象庁 Japan Meteorological. "気象庁 – 計測震度の算出方法". ↑ "JMA seismic intensity scale". ↑ "The Great Hanshin Earthquake Disaster". 9 September 2006.