Reviewed by USGSGuam97y ago
M7.2 earthquake 265 km S of Merizo Village, Guam
Wednesday, January 28, 1931, 21:24:11 UTC · 10.873°N, 144.461°E
A magnitude 7.2 earthquake struck 265 km S of Merizo Village, Guam on Wednesday, January 28, 1931, 21:24:11 UTC, at a depth of 15.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 7.2
- Major · mw
- Depth
- 15 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
106 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
15 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 9 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.1261 km S of Merizo Village, GuamMay 9, 1917 · 7 km NW of this epicenter
- 7.098 km SSE of Inarajan Village, GuamDecember 9, 1909 · 179 km N of this epicenter
- 6.4279 km S of Merizo Village, GuamMay 6, 1917 · 30 km W of this epicenter
- 6.3193 km ENE of Fais, MicronesiaMarch 30, 1919 · 260 km W of this epicenter
- 6.3146 km WSW of Merizo Village, GuamNovember 24, 1917 · 242 km NW of this epicenter
- 6.0247 km NE of Fais, MicronesiaJuly 17, 1925 · 268 km W of this epicenter
- 6.0206 km SW of Merizo Village, GuamMay 1, 1929 · 169 km NW of this epicenter
- 5.9119 km SSW of Merizo Village, GuamOctober 10, 1928 · 158 km N 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:
- 1909M8.0
Guam
9 Dec 1909 · 190 km away · intensity VIII
Moderate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.