Reviewed by USGSPeru25y ago
M4.6 earthquake 99 km S of Atico, Peru
Monday, August 20, 2001, 07:31:30 UTC · 17.103°S, 73.523°W
A magnitude 4.6 earthquake struck 99 km S of Atico, Peru on Monday, August 20, 2001, 07:31:30 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M4.7 on August 14, 2001.
- Magnitude
- 4.6
- 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
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
50 km
from the nearest mapped plate boundary, between the Nazca and Altiplano 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 M3.8 on September 18, 2001. 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 296 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.46 km SSW of Atico, PeruJune 23, 2001 · 94 km N of this epicenter
- 8.121 km NNE of Minas de Marcona, PeruAugust 24, 1942 · 280 km NW of this epicenter
- 7.737 km SSW of Atico, PeruAugust 6, 1913 · 67 km N of this epicenter
- 7.651 km SW of Punta de Bombón, PeruJuly 7, 2001 · 161 km E of this epicenter
- 7.235 km N of El Cardo, PeruOctober 11, 1922 · 126 km NE of this epicenter
- 7.212 km NNE of Cono Norte, PeruFebruary 26, 1914 · 232 km NE of this epicenter
- 7.121 km SSE of Nazca, PeruJanuary 15, 1960 · 274 km NW of this epicenter
- 7.130 km SW of Islay (Matarani), PeruApril 12, 1988 · 130 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 31 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 1,587 recorded deaths. The most severe:
- 1833M7.7
Peru: Tacna; Chile: Arica
18 Sep 1833 · 295 km away · intensity VIII
700 deathsSevere damage ($5–24M)tsunami
- 1784M8.0
Arequipa,Camana,Moquegua,Tambo
13 May 1784 · 175 km away · intensity X
383 deathsSevere damage ($5–24M)tsunami
- 1821
Camana, Ocona, Caraveli
10 Jul 1821 · 126 km away · intensity VIII
162 deathsSevere damage ($5–24M)
- 2001M8.4
Arequipa, Moquegua, Tacna, Ayacucho
23 Jun 2001 · 94 km away · intensity VIII
103 deaths$200 million damagetsunami
- 1991M4.7
Maca, Chivay, Yanque
23 Jul 1991 · 261 km away · intensity V
92 deathsModerate damage ($1–5M)
- 1960M7.8
Arequipa,Chuquibamba,Caraveli,Cotahuasi
13 Jan 1960 · 172 km away · intensity X
63 deathsSevere damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.