According to this item from TBS News, we’ve had more than 2000 Level 1 or higher quakes since April 14th. This is more activity than has been recorded for any similar quake since such record keeping began. On the whole, however, the frequency and intensity of the quakes is declining. Click on the link to see the Japanese news video:
http://news.tbs.co.jp/newseye/tbs_newseye2849580.html
– Kirk