Reviewed by USGSAmerican Samoa102y ago
M6.3 earthquake 171 km S of Vailoatai, American Samoa
Friday, June 19, 1925, 07:50:28 UTC · 15.897°S, 170.995°W
A magnitude 6.3 earthquake struck 171 km S of Vailoatai, American Samoa on Friday, June 19, 1925, 07:50:28 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.4 on May 26, 1920.
- Magnitude
- 6.3
- Strong · 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
44 kilotons of TNT
That is about 3 times the Hiroshima bomb. It released about 92 times the energy of a magnitude 5.0.
Tectonic setting
141 km
from the nearest mapped plate boundary, between the Tonga 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 100 km
USGS has not published any M2.5+ earthquake within 100 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:
- 8.0The 1917 Samoa-Tonga EarthquakeJune 26, 1917 · 264 km W of this epicenter
- 6.8100 km SE of Hihifo, TongaDecember 20, 1914 · 248 km W of this epicenter
- 6.7144 km ENE of Hihifo, TongaOctober 20, 1916 · 168 km W of this epicenter
- 6.4115 km NNE of Hihifo, TongaMay 26, 1920 · 289 km W of this epicenter
- 6.372 km ESE of Hihifo, TongaJuly 7, 1924 · 242 km W of this epicenter
- 6.285 km NE of Samamea, SamoaMay 18, 1917 · 267 km N of this epicenter
- 6.2156 km NE of Neiafu, TongaNovember 29, 1921 · 285 km SW of this epicenter
- 6.2211 km SSW of Vailoatai, American SamoaJune 28, 1917 · 68 km W 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, which together caused about 2 recorded deaths. The most severe:
- 1917M8.3
Samoa Islands
26 Jun 1917 · 219 km away
2 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.