Reviewed by USGSPeru85y ago
M6.3 earthquake 60 km W of San Juan, Peru
Tuesday, August 25, 1942, 20:15:50 UTC · 15.291°S, 75.716°W
A magnitude 6.3 earthquake struck 60 km W of San Juan, Peru on Tuesday, August 25, 1942, 20:15:50 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M8.1 on August 24, 1942.
- Magnitude
- 6.3
- 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 earthquakeDashed circle: 100 km aftershock search area
In context
How big was it, and why here?
Energy released
44 kilotons of TNT
That is about 3 times the Hiroshima bomb. It released about 92 times the energy of a magnitude 5.0.
Tectonic setting
13 km
from the nearest mapped plate boundary, between the Altiplano 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 lists 2 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M6.0 on August 25, 1942. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 16 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.121 km NNE of Minas de Marcona, PeruAugust 24, 1942 · 79 km E of this epicenter
- 7.737 km SSW of Atico, PeruAugust 6, 1913 · 253 km SE of this epicenter
- 6.913 km SSW of San Juan, PeruOctober 3, 1916 · 166 km E of this epicenter
- 6.7165 km SSW of Atiquipa, PeruJuly 28, 1913 · 223 km S of this epicenter
- 6.7103 km SSW of Atico, PeruSeptember 13, 1919 · 266 km SE of this epicenter
- 6.691 km SSW of Santiago, PeruJune 25, 1930 · 53 km NW of this epicenter
- 6.512 km S of Chiara, PeruJanuary 9, 1921 · 268 km NE of this epicenter
- 6.512 km WNW of Cotaruse, PeruFebruary 28, 1920 · 277 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 96 recorded deaths. The most severe:
- 1914
Pararca,Paysa,Colta,Oyala
2 Dec 1914 · 270 km away · intensity X
34 deathsSevere damage ($5–24M)
- 1813
Ica
30 Mar 1813 · 137 km away · intensity VII
32 deathsModerate damage ($1–5M)
- 1942M8.2
Ica, Nazca
24 Aug 1942 · 44 km away · intensity IX
30 deathsSevere damage ($5–24M)tsunami
- 1913M7.9
Caraveli, Chuquibamba, Ocona, Atico
6 Aug 1913 · 264 km away · intensity X
Severe damage ($5–24M)tsunami
- 1914
Caraveli,Nazca,Ica,Atico
11 Sep 1914 · 244 km away · intensity VII
Moderate damage ($1–5M)
- 1913M7.0
Arequipa
28 Jul 1913 · 296 km away · intensity IX
Limited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.