Reviewed by USGS80y ago
M7.2 earthquake in Mariana Islands region
Thursday, June 19, 1947, 07:34:41 UTC · 21.570°N, 145.469°E
A magnitude 7.2 earthquake struck in Mariana Islands region on Thursday, June 19, 1947, 07:34:41 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M7.5 on February 24, 1934.
- Magnitude
- 7.2
- Major · mw
- Depth
- 35 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 earthquake
In context
How big was it, and why here?
Energy released
951 kilotons of TNT
That is about 63 times the Hiroshima bomb. It released about 1,995 times the energy of a magnitude 5.0.
Tectonic setting
92 km
from the nearest mapped plate boundary, between the Mariana and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
35 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 200 km
USGS has not published any M2.5+ earthquake within 200 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 19 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.5Volcano Islands, Japan regionFebruary 24, 1934 · 227 km NW of this epicenter
- 7.2Mariana Islands regionJuly 11, 1905 · 163 km W of this epicenter
- 7.0Mariana Islands regionJune 13, 1947 · 23 km N of this epicenter
- 6.6Volcano Islands, Japan regionMay 17, 1939 · 271 km NW of this epicenter
- 6.6Mariana Islands regionJune 13, 1947 · 28 km NE of this epicenter
- 6.6Volcano Islands, Japan regionMarch 11, 1931 · 275 km NW of this epicenter
- 6.4Mariana Islands regionAugust 27, 1919 · 78 km E of this epicenter
- 6.2Mariana Islands regionJune 19, 1947 · 69 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 1 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1914M8.1
Volcano Islands
24 Nov 1914 · 259 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.