Reviewed by USGSChile78y ago
M7.0 earthquake 15 km SSW of Nacimiento, Chile
Wednesday, April 20, 1949, 03:29:09 UTC · 37.634°S, 72.713°W
A magnitude 7.0 earthquake struck 15 km SSW of Nacimiento, Chile on Wednesday, April 20, 1949, 03:29:09 UTC, at a depth of 57.7 km (shallow). It is the strongest earthquake within 300 km since an M7.8 on January 25, 1939.
- Magnitude
- 7.0
- Major · mw
- Depth
- 58 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
494 kilotons of TNT
That is about 33 times the Hiroshima bomb. It released about 1,035 times the energy of a magnitude 5.0.
Tectonic setting
166 km
from the nearest mapped plate boundary, between the Nazca and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
58 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 24 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.826 km WNW of San Carlos, ChileJanuary 25, 1939 · 155 km N of this epicenter
- 7.730 km NNE of Constitución, ChileDecember 1, 1928 · 286 km N of this epicenter
- 7.350 km SSW of Carahue, ChileDecember 10, 1920 · 176 km S of this epicenter
- 7.247 km NW of Cauquenes, ChileDecember 2, 1928 · 214 km N of this epicenter
- 7.019 km SW of Angol, ChileAugust 20, 1920 · 34 km SW of this epicenter
- 6.948 km SSE of Panguipulli, ChileJune 13, 1907 · 274 km S of this epicenter
- 6.717 km NNW of Loncoche, ChileAugust 19, 1906 · 177 km S of this epicenter
- 6.672 km SW of Carahue, ChileMarch 12, 1922 · 195 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 15 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 30,460 recorded deaths. The most severe:
- 1939M8.3
Chillan
25 Jan 1939 · 159 km away · intensity X
30,000 deaths$920 million damagetsunami
- 1928M7.6
Talca, Chillan, Santiago, San Fernando
1 Dec 1928 · 300 km away · intensity IX
279 deathsSevere damage ($5–24M)tsunami
- 1751M8.5
Concepcion, Chillan, Talca, Tutuben, Curico
25 May 1751 · 131 km away · intensity XI
65 deathsSevere damage ($5–24M)tsunami
- 1949M7.3
Angol, Traiguen
20 Apr 1949 · 80 km away
57 deathsModerate damage ($1–5M)tsunami
- 1835M8.2
Concepcion
20 Feb 1835 · 94 km away · intensity XI
53 deathsExtreme damage ($25M+)tsunami
- 1898M6.5
Concepcion
23 Jul 1898 · 94 km away · intensity VIII
6 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.