Reviewed by USGSNorthern Mariana Islands33y ago
M6.5 earthquake 112 km NE of Saipan, Northern Mariana Islands
Sunday, June 6, 1993, 13:23:20 UTC · 15.823°N, 146.595°E
A magnitude 6.5 earthquake struck 112 km NE of Saipan, Northern Mariana Islands on Sunday, June 6, 1993, 13:23:20 UTC, at a depth of 13.5 km (shallow). It is the strongest earthquake within 300 km since an M7.6 on April 5, 1990.
- Magnitude
- 6.5
- Strong · mwb
- Depth
- 14 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 100 km aftershock search area
In context
How big was it, and why here?
Energy released
85 kilotons of TNT
That is about 6 times the Hiroshima bomb. It released about 178 times the energy of a magnitude 5.0.
Tectonic setting
117 km
from the nearest mapped plate boundary, between the Mariana and Pacific plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
14 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.
After the main event
Aftershocks within 100 km
USGS lists 1 M2.5+ earthquake within 100 km in the following 30 days; the largest was M4.3 on June 11, 1993. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 317 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.7Mariana Islands regionDecember 28, 1940 · 280 km N of this epicenter
- 7.6198 km E of Saipan, Northern Mariana IslandsApril 5, 1990 · 132 km SE of this epicenter
- 7.5Mariana Islands regionJanuary 17, 1940 · 214 km NE of this epicenter
- 7.2Pagan region, Northern Mariana IslandsOctober 24, 1930 · 292 km N of this epicenter
- 7.1233 km NE of Saipan, Northern Mariana IslandsJuly 2, 1949 · 121 km NE of this epicenter
- 7.0176 km ESE of San Jose Village, Northern Mariana IslandsMay 18, 1913 · 182 km S of this epicenter
- 7.032 km NNE of Yigo Village, GuamOctober 26, 1912 · 284 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 3 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1902M8.1
Agana
22 Sep 1902 · 250 km away · intensity IX
Severe damage ($5–24M)
- 1975M6.1
Guam
1 Nov 1975 · 296 km away · intensity VII
Limited damage (under $1M)
- 1990M7.5
Saipan; Guam
5 Apr 1990 · 132 km away · intensity IV
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.