Reviewed by USGSPeru52y ago
M4.0 earthquake 45 km WSW of San Bartolo, Peru
Sunday, October 13, 1974, 17:34:28 UTC · 12.559°S, 77.157°W
A magnitude 4.0 earthquake struck 45 km WSW of San Bartolo, Peru on Sunday, October 13, 1974, 17:34:28 UTC, at a depth of 33.0 km (shallow).
- Magnitude
- 4.0
- Light · mb
- Depth
- 33 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: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
15 tons of TNT
That is about 1/998 of the Hiroshima bomb. A magnitude 5.0 releases about 32 times more energy.
Tectonic setting
141 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
33 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 50 km
USGS lists 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.5 on October 24, 1974. 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 52 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.221 km SE of Huacho, PeruMay 24, 1940 · 152 km N of this epicenter
- 8.167 km W of Paramonga, PeruOctober 17, 1966 · 250 km NW of this epicenter
- 7.677 km WSW of Callao, PeruOctober 3, 1974 · 77 km NW of this epicenter
- 6.928 km W of Paramonga, PeruSeptember 24, 1963 · 235 km NW of this epicenter
- 6.710 km SSW of Huacho, PeruMay 24, 1940 · 160 km N of this epicenter
- 6.691 km SSW of Santiago, PeruJune 25, 1930 · 291 km SE of this epicenter
- 6.616 km S of Comas, PeruOctober 1, 1969 · 237 km E of this epicenter
- 6.518 km WSW of Oxapampa, PeruDecember 24, 1937 · 275 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 35 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 6,569 recorded deaths. The most severe:
- 1746M8.0
Lima, Callao
29 Oct 1746 · 63 km away · intensity XI
5,941 deathsExtreme damage ($25M+)tsunami
- 1940M8.2
Peru
24 May 1940 · 230 km away · intensity X
179 deathsSevere damage ($5–24M)tsunami
- 1969M6.6
Huaytapallana, Lampa, Chilifruta
1 Oct 1969 · 242 km away · intensity XI
130 deaths$5 million damage
- 1966M8.1
Lima,Huacho,Huaura, Chancay,Supe,San Nicolas
17 Oct 1966 · 258 km away · intensity IX
110 deaths$35 million damagetsunami
- 1974M8.1
Lima, Callao
3 Oct 1974 · 76 km away · intensity IX
78 deaths$10 million damagetsunami
- 1813
Ica
30 Mar 1813 · 256 km away · intensity VII
32 deathsModerate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.