Recent Japan Earthquake Activity

Based on data from the initial EEW announcement Click on event for subsequent announcements.
Intensity	Report Time (JST)	Magnitude	Depth	Epicenter
3	2012-02-22 09:53:55	M4.5	10km	Off the east coast of Chiba
4	2012-02-19 14:54:44	M5.2	10km	Off the coast of Ibaraki
3	2012-02-18 23:20:27	M4.7	10km	Off the coast of Ibaraki
4	2012-02-18 14:13:10	M4.5	10km	Northwest Chiba
3	2012-02-18 13:56:32	M4.0	10km	Northwest Chiba
3	2012-02-18 10:59:13	M4.7	50km	Off the coast of Uraga
3	2012-02-18 09:38:38	M4.6	30km	Off the east coast of Chiba
3	2012-02-18 03:10:24	M4.6	30km	Near the coast of Ishigakijima
3	2012-02-17 06:00:31	M4.2	30km	West Shizuoka
3	2012-02-16 14:09:37	M4.8	30km	Off the coast of Miyagi
3	2012-02-16 02:32:18	M4.8	30km	Off the coast of Ibaraki
3	2012-02-15 15:28:35	M5.0	50km	Off the coast of Fukushima
4	2012-02-15 13:36:30	M4.7	10km	East Oshimashi Subprefecture
3	2012-02-15 04:15:06	M5.1	10km	Off the east coast of Chiba
3	2012-02-14 15:22:00	M5.3	50km	Off the coast of Ibaraki
3	2012-02-14 12:27:49	M5.3	40km	Off the coast of Ibaraki
3	2012-02-12 17:26:04	M4.4	30km	Off the coast of Ibaraki
3	2012-02-12 04:55:48	M4.7	30km	Off the coast of Miyagi
3	2012-02-11 10:26:57	M4.3	10km	Southern Ibaraki
3	2012-02-10 13:56:55	M4.3	10km	Northern inland of Akita
3	2012-02-09 12:55:22	M4.4	10km	Hyuganada
3	2012-02-08 06:41:19	M4.1	10km	Off the coast of Ibaraki
3	2012-02-06 12:22:41	M4.0	10km	Off the coast of Kushiro
3	2012-02-06 07:10:51	M4.8	10km	THIS IS ONLY A TEST
3	2012-02-06 07:10:51	M4.8	10km	THIS IS ONLY A TEST 2
3	2012-02-06 07:05:48	M4.8	10km	Off the coast of Ibaraki
3	2012-02-06 07:05:46	M4.8	10km	Off the coast of Ibarak
3	2012-02-05 08:59:05	M4.8	20km	Off the coast of Ibaraki
3	2012-02-04 11:54:25	M5.1	90km	Near the coast of Yonagunijima
3	2012-02-04 08:32:29	M4.5	50km	Off the coast of Iwate

WARNING: DATA BASED ON ITITIAL EEW ANNOUNCEMENTS - OVERALL INTENSITY AND MAGNITUDE WILL BE DIFFERENT THAN VALUES SHOWN! ~ [source]

About earthquake data

J1 monitors a Twitter account that receives alerts from the Japan Meteorlogical Agency's Earthquake Early Warning system. This system will then relay information about earthquakes with an intensity on the Japanese scale of 0~7 of at least a 3.

Disclaimer of Earthquake Early Warning on J1 Radio

Data received by J1 that came from the JMA Earthquake Early Warnning (EEW) system should not be considered as an early warning due to internet related delays. It can be as long as about 5 minutes from an activation to the time it's available to J1 sources. While we make every effort to get out information, this is in no way a guaranteed service and is subject to interruption at any time. Those in Japan who hear an alert tone over J1 Radio should immediately monitor local radio or television broadcasts or their mobile phone for preliminary official EEW information. Therefore, REC Networks/J1 Radio can not be liable due to the delay or the failure to relay EEW information and J1's use of EEW data should not be used in replacement of official Japanese resources.

Detailed information about an earthquake is available usually about 5 minutes following the event from the Japanese Meteorlogical Agency: http://www.jma.go.jp/en/quake/