Reviewed by USGS80y ago
M6.7 earthquake central Mid-Atlantic Ridge
Thursday, April 24, 1947, 19:35:15 UTC · 8.127°N, 38.699°W
A magnitude 6.7 earthquake struck central Mid-Atlantic Ridge on Thursday, April 24, 1947, 19:35:15 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.8 on April 21, 1919.
- Magnitude
- 6.7
- 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
142 kilotons of TNT
That is about 9 times the Hiroshima bomb. It released about 299 times the energy of a magnitude 5.0.
Tectonic setting
4 km
from the nearest mapped plate boundary, between the African and South American 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 11 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.8central Mid-Atlantic RidgeApril 21, 1919 · 214 km NW of this epicenter
- 6.4central Mid-Atlantic RidgeSeptember 12, 1915 · 158 km E of this epicenter
- 6.4central Mid-Atlantic RidgeJuly 20, 1906 · 142 km E of this epicenter
- 6.3central Mid-Atlantic RidgeDecember 7, 1915 · 30 km N of this epicenter
- 6.3central Mid-Atlantic RidgeSeptember 14, 1945 · 130 km SE of this epicenter
- 6.2central Mid-Atlantic RidgeJanuary 27, 1929 · 193 km SE of this epicenter
- 5.9central Mid-Atlantic RidgeOctober 1, 1943 · 45 km SE of this epicenter
- 5.8central Mid-Atlantic RidgeMay 31, 1932 · 149 km SE of this epicenter