Home › 1940 › Mariana Islands

M7.7 earthquake, Mariana Islands, 1940-12-28

MagnitudeM7.7mw

This page is updated only once a day and is not an alert service. For current earthquake and tsunami information, check the Japan Meteorological Agency, the USGS and your local authorities.

Depth15 km

Time (UTC)1940-12-28 16:37

Rank in 19403 / 105among M6+

Rank since 1900248 / 14,458

Energy vs an M6×355approx.

Mariana Islands region · 18.20, 147.46

M6.5+ within 300 km (largest first)

2016 M7.7M7.7

1940 M7.7M7.7

1902 M7.5M7.5

1940 M7.5M7.5

1930 M7.2M7.2

2007 M7.2M7.2

1949 M7.1M7.1

1995 M7.1M7.1

2023 M6.9M6.9

1962 M6.9M6.9

2013 M6.8M6.8

2024 M6.8M6.8

Earlier M6+ within 300 km

Event	Time (UTC)	Depth	Place
M7.5 1940-01-17	1940-01-17 01:14	15 km	Mariana Islands region
M6.5 1938-12-01	1938-12-01 02:12	25 km	258 km NE of Saipan, Northern Mariana Islands
M6.3 1932-03-19	1932-03-19 10:59	15 km	215 km ENE of Saipan, Northern Mariana Islands
M6.5 1930-10-28	1930-10-28 21:10	25 km	Pagan region, Northern Mariana Islands
M7.2 1930-10-24	1930-10-24 20:15	25 km	Pagan region, Northern Mariana Islands
M6.6 1921-02-10	1921-02-10 23:53	15 km	Alamagan region, Northern Mariana Islands
M7.5 1902-09-22	1902-09-22 01:46	–	Northern Mariana Islands

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.