Reviewed by USGSChile62y ago
M7.4 earthquake 7 km SSE of La Ligua, Chile
Sunday, March 28, 1965, 16:33:15 UTC · 32.516°S, 71.206°W
A magnitude 7.4 earthquake struck 7 km SSE of La Ligua, Chile on Sunday, March 28, 1965, 16:33:15 UTC, at a depth of 68.3 km (shallow). It is the strongest earthquake within 300 km since an M8.1 on April 6, 1943.
- Magnitude
- 7.4
- Major · mw
- Depth
- 68 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
1.9 megatons of TNT
That is about 126 times the Hiroshima bomb. It released about 3,981 times the energy of a magnitude 5.0.
Tectonic setting
147 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
68 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 49 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.2The 1906 Valparaiso, Chile EarthquakeAugust 17, 1906 · 22 km NW of this epicenter
- 8.145 km NNW of Illapel, ChileApril 6, 1943 · 140 km N of this epicenter
- 7.237 km S of San Antonio, ChileMarch 18, 1931 · 160 km S of this epicenter
- 7.060 km WSW of Coquimbo, ChileApril 19, 1955 · 274 km N of this epicenter
- 6.94 km ESE of Chimbas, ArgentinaJanuary 15, 1944 · 280 km NE of this epicenter
- 6.972 km WNW of Calingasta, ArgentinaJuly 27, 1917 · 202 km NE of this epicenter
- 6.957 km W of Ovalle, ChileFebruary 15, 1917 · 229 km N of this epicenter
- 6.88 km W of Nueve de Julio, ArgentinaJune 11, 1952 · 273 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 38 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 29,185 recorded deaths. The most severe:
- 1861
Mendoza, San Luiz
20 Mar 1861 · 227 km away · intensity IX
14,000 deathsExtreme damage ($25M+)tsunami
- 1944M6.9
San Juan Province
15 Jan 1944 · 280 km away · intensity IX
10,000 deaths$100 million damage
- 1906M8.2
South Central
17 Aug 1906 · 92 km away · intensity XI
4,000 deaths$100 million damagetsunami
- 1965M7.3
Central
28 Mar 1965 · 13 km away
400 deaths$125 million damage
- 1920M6.7
Mendoza
17 Dec 1920 · 271 km away · intensity VIII
400 deathsSevere damage ($5–24M)
- 1928M7.6
Talca, Chillan, Santiago, San Fernando
1 Dec 1928 · 286 km away · intensity IX
279 deathsSevere damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.