Reviewed by USGSChile88y ago
M7.8 earthquake 26 km WNW of San Carlos, Chile
Wednesday, January 25, 1939, 03:32:14 UTC · 36.296°S, 72.213°W
A magnitude 7.8 earthquake struck 26 km WNW of San Carlos, Chile on Wednesday, January 25, 1939, 03:32:14 UTC, at a depth of 35.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 7.8
- Major · mw
- Depth
- 35 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
9.0 megatons of TNT
That is about 597 times the Hiroshima bomb. It released about 18,836 times the energy of a magnitude 5.0.
Tectonic setting
171 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
35 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 26 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.730 km NNE of Constitución, ChileDecember 1, 1928 · 135 km N of this epicenter
- 7.7103 km NW of Constitución, ChileJanuary 30, 1914 · 197 km NW of this epicenter
- 7.247 km NW of Cauquenes, ChileDecember 2, 1928 · 80 km NW of this epicenter
- 7.237 km S of San Antonio, ChileMarch 18, 1931 · 270 km N of this epicenter
- 7.019 km SW of Angol, ChileAugust 20, 1920 · 189 km S of this epicenter
- 6.599 km SE of Rengo, ChileJanuary 30, 1914 · 251 km NE of this epicenter
- 6.419 km NE of Tomé, ChileOctober 15, 1936 · 57 km SW of this epicenter
- 6.3210 km WNW of Constitución, ChileSeptember 6, 1926 · 280 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 13 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 30,403 recorded deaths. The most severe:
- 1939M8.3
Chillan
25 Jan 1939 · 6 km away · intensity X
30,000 deaths$920 million damagetsunami
- 1928M7.6
Talca, Chillan, Santiago, San Fernando
1 Dec 1928 · 145 km away · intensity IX
279 deathsSevere damage ($5–24M)tsunami
- 1751M8.5
Concepcion, Chillan, Talca, Tutuben, Curico
25 May 1751 · 79 km away · intensity XI
65 deathsSevere damage ($5–24M)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
- 1871M7.5
Central
25 Mar 1871 · 146 km away
Severe damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.