Reviewed by USGSPeru87y ago
M8.2 earthquake 21 km SE of Huacho, Peru
Friday, May 24, 1940, 16:33:59 UTC · 11.217°S, 77.438°W
A magnitude 8.2 earthquake struck 21 km SE of Huacho, Peru on Friday, May 24, 1940, 16:33:59 UTC, at a depth of 45.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 8.2
- Great · mw
- Depth
- 45 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VIII
- Severe (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 400 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
30 megatons of TNT
That is about 1,998 times the Hiroshima bomb. It released about 63,096 times the energy of a magnitude 5.0.
Tectonic setting
198 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
45 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 400 km
USGS lists 1 M2.5+ earthquake within 400 km in the following 30 days; the largest was M6.7 on May 24, 1940. 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 5 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.518 km WSW of Oxapampa, PeruDecember 24, 1937 · 215 km E of this epicenter
- 6.3102 km SW of Huarmey, PeruSeptember 29, 1916 · 174 km NW of this epicenter
- 6.111 km WNW of Sayán, PeruJanuary 20, 1932 · 23 km NE of this epicenter
- 6.1123 km WSW of Puerto Casma, PeruApril 3, 1931 · 262 km NW of this epicenter
- 5.958 km WSW of Puerto Santa, PeruNovember 21, 1927 · 295 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 20 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 7,670 recorded deaths. The most severe:
- 1746M8.0
Lima, Callao
29 Oct 1746 · 90 km away · intensity XI
5,941 deathsExtreme damage ($25M+)tsunami
- 1725M7.7
Trujillo, Ancash, Lima
7 Jan 1725 · 300 km away · intensity IX
1,500 deathsSevere damage ($5–24M)
- 1940M8.2
Peru
24 May 1940 · 93 km away · intensity X
179 deathsSevere damage ($5–24M)tsunami
- 1828M8.3
Lima, Callao
30 Mar 1828 · 109 km away · intensity VII
30 deathsModerate damage ($1–5M)tsunami
- 1937M6.5
Huancabamba,Oxapampa,El Progreso,San David
24 Dec 1937 · 115 km away · intensity X
15 deathsModerate damage ($1–5M)
- 1865
Peru
8 Jan 1865 · 95 km away
5 deathsLimited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.