Reviewed by USGSAmerican Samoa110y ago
M6.2 earthquake 211 km SSW of Vailoatai, American Samoa
Thursday, June 28, 1917, 13:55:07 UTC · 16.100°S, 171.600°W
A magnitude 6.2 earthquake struck 211 km SSW of Vailoatai, American Samoa on Thursday, June 28, 1917, 13:55:07 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M8.0 on June 26, 1917.
- Magnitude
- 6.2
- 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
26 kilotons of TNT
That is about 2 times the Hiroshima bomb. It released about 55 times the energy of a magnitude 5.0.
Tectonic setting
75 km
from the nearest mapped plate boundary, between the Tonga and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
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 5 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 · 217 km NW of this epicenter
- 6.9127 km S of Hihifo, TongaMay 8, 1913 · 277 km SW of this epicenter
- 6.8100 km SE of Hihifo, TongaDecember 20, 1914 · 180 km W of this epicenter
- 6.7144 km ENE of Hihifo, TongaOctober 20, 1916 · 116 km NW of this epicenter
- 6.285 km NE of Samamea, SamoaMay 18, 1917 · 299 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, which together caused about 2 recorded deaths. The most severe:
- 1917M8.3
Samoa Islands
26 Jun 1917 · 164 km away
2 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.