Reviewed by USGSPeru30y ago
M3.9 earthquake 77 km WNW of San Juan, Peru
Wednesday, January 22, 1997, 22:16:08 UTC · 15.217°S, 75.865°W
A magnitude 3.9 earthquake struck 77 km WNW of San Juan, Peru on Wednesday, January 22, 1997, 22:16:08 UTC, at a depth of 33.0 km (shallow).
- Magnitude
- 3.9
- Minor · 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
11 tons of TNT
That is about 1/1,410 of the Hiroshima bomb. A magnitude 5.0 releases about 45 times more energy.
Tectonic setting
31 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
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 M4.9 on February 17, 1997. 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 197 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 · 92 km E of this epicenter
- 7.737 km SSW of Atico, PeruAugust 6, 1913 · 271 km SE of this epicenter
- 7.760 km SW of Changuillo, PeruNovember 12, 1996 · 32 km NE of this epicenter
- 7.121 km SSE of Nazca, PeruJanuary 15, 1960 · 110 km E of this epicenter
- 6.913 km SSW of San Juan, PeruOctober 3, 1916 · 179 km E of this epicenter
- 6.7165 km SSW of Atiquipa, PeruJuly 28, 1913 · 236 km SE of this epicenter
- 6.7103 km SSW of Atico, PeruSeptember 13, 1919 · 283 km SE of this epicenter
- 6.691 km SSW of Santiago, PeruJune 25, 1930 · 36 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 22 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 153 recorded deaths. The most severe:
- 1914
Pararca,Paysa,Colta,Oyala
2 Dec 1914 · 286 km away · intensity X
34 deathsSevere damage ($5–24M)
- 1813
Ica
30 Mar 1813 · 134 km away · intensity VII
32 deathsModerate damage ($1–5M)
- 1942M8.2
Ica, Nazca
24 Aug 1942 · 28 km away · intensity IX
30 deathsSevere damage ($5–24M)tsunami
- 1996M7.7
Chincha Alta, Acari, Nazca, Marcona
12 Nov 1996 · 32 km away · intensity VIII
14 deathsExtreme damage ($25M+)tsunami
- 1981M5.2
Central
22 Jun 1981 · 270 km away
10 deaths$5 million damage
- 1981M4.8
Ayacucho
18 Apr 1981 · 281 km away
8 deathsModerate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.