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M6.6 earthquake, Japan, 2004-10-23

MagnitudeM6.6mwc

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Depth16 km

Time (UTC)2004-10-23 08:56

Rank in 200435 / 157among M6+

Rank since 19003643 / 14,458

Energy vs an M6×8approx.

8 km SSW of Ojiya, Japan · 37.23, 138.78

M5.5+ within 100 km in the next 30 days

Event	Time (UTC)	Depth	Place
M5.7 2004-10-23	2004-10-23 08:59	10 km	6 km ESE of Ojiya, Japan
M6.1 2004-10-23	2004-10-23 09:03	10 km	2 km NE of Ojiya, Japan
M5.8 2004-10-23	2004-10-23 09:11	18 km	15 km SSE of Kashiwazaki, Japan
M6.3 2004-10-23	2004-10-23 09:34	10 km	2 km NNE of Ojiya, Japan
M5.6 2004-10-23	2004-10-23 09:57	10 km	6 km NNW of T?kamachi, Japan
M5.7 2004-10-23	2004-10-23 10:36	10 km	15 km NW of T?kamachi, Japan
M5.7 2004-10-23	2004-10-23 10:45	10 km	11 km SE of Kashiwazaki, Japan
M5.7 2004-10-24	2004-10-24 21:04	11 km	8 km W of Ojiya, Japan
M6.0 2004-10-27	2004-10-27 01:40	14 km	7 km ESE of Ojiya, Japan
M5.5 2004-11-08	2004-11-08 02:15	10 km	6 km S of Nagaoka, Japan

M6.5+ within 300 km (largest first)

1923 M8.0M8.0

2011 M7.9M7.9

1923 M7.8M7.8

1938 M7.8M7.8

1938 M7.7M7.7

1964 M7.6M7.6

2024 M7.5M7.5

2022 M7.3M7.3

1923 M7.2M7.2

1961 M7.2M7.2

1924 M7.1M7.1

1943 M7.1M7.1

Earlier M6+ within 300 km

Event	Time (UTC)	Depth	Place
M6.0 2004-04-03	2004-04-03 23:02	31 km	37 km ESE of Hitachi, Japan
M6.1 2003-07-25	2003-07-25 22:13	6 km	7 km NW of Matsushima, Japan
M6.0 2000-07-20	2000-07-20 18:39	47 km	31 km ESE of Hitachi, Japan
M6.2 2000-06-03	2000-06-03 08:54	62 km	6 km SE of Narut?, Japan
M6.2 1996-09-11	1996-09-11 02:37	55 km	23 km SSE of Hasaki, Japan
M6.0 1996-08-10	1996-08-10 18:12	10 km	25 km NE of Shinj?, Japan
M6.0 1995-01-09	1995-01-09 18:00	33 km	48 km ENE of Hasaki, Japan
M6.6 1993-02-07	1993-02-07 13:27	11 km	69 km NNE of Nanao, Japan
M6.0 1991-08-06	1991-08-06 14:49	28 km	19 km E of Hasaki, Japan
M6.1 1990-08-05	1990-08-05 03:36	27 km	43 km E of ?arai, Japan

Energy ratio uses the rule that one magnitude unit is about 32 times the energy. Magnitudes and locations are USGS values and can differ from national agencies. Older records are less complete and less precise.