Reviewed by USGSSamoa110y ago
M6.2 earthquake 85 km NE of Samamea, Samoa
Friday, May 18, 1917, 19:05:27 UTC · 13.502°S, 170.877°W
A magnitude 6.2 earthquake struck 85 km NE of Samamea, Samoa on Friday, May 18, 1917, 19:05:27 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.7 on October 20, 1916.
- 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
32 kilotons of TNT
That is about 2 times the Hiroshima bomb. It released about 68 times the energy of a magnitude 5.0.
Tectonic setting
261 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 1 M5.0+ earthquake within 300 km before this one (catalog from 1900; older records are less complete). The strongest: