Reviewed by USGSPeru25y ago
M4.1 earthquake 56 km SSW of Islay (Matarani), Peru
Saturday, September 22, 2001, 12:51:32 UTC · 17.484°S, 72.256°W
A magnitude 4.1 earthquake struck 56 km SSW of Islay (Matarani), Peru on Saturday, September 22, 2001, 12:51:32 UTC, at a depth of 49.4 km (shallow).
- Magnitude
- 4.1
- Light · mb
- Depth
- 49 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
21 tons of TNT
That is about 1/707 of the Hiroshima bomb. A magnitude 5.0 releases about 22 times more energy.
Tectonic setting
99 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
49 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.0 on October 13, 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 303 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 · 200 km NW of this epicenter
- 7.737 km SSW of Atico, PeruAugust 6, 1913 · 190 km NW of this epicenter
- 7.651 km SW of Punta de Bombón, PeruJuly 7, 2001 · 20 km E of this epicenter
- 7.235 km N of El Cardo, PeruOctober 11, 1922 · 141 km N of this epicenter
- 7.212 km NNE of Cono Norte, PeruFebruary 26, 1914 · 160 km NE of this epicenter
- 7.268 km SSE of Arica, ChileAugust 8, 1987 · 294 km SE of this epicenter
- 7.130 km SW of Islay (Matarani), PeruApril 12, 1988 · 33 km N of this epicenter
- 7.021 km SW of Santa Rita de Siguas, PeruJanuary 15, 1958 · 96 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 43 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 26,593 recorded deaths. The most severe:
- 1868M8.5
Arica
13 Aug 1868 · 182 km away · intensity XI
25,000 deaths$300 million damagetsunami
- 1833M7.7
Peru: Tacna; Chile: Arica
18 Sep 1833 · 157 km away · intensity VIII
700 deathsSevere damage ($5–24M)tsunami
- 1784M8.0
Arequipa,Camana,Moquegua,Tambo
13 May 1784 · 113 km away · intensity X
383 deathsSevere damage ($5–24M)tsunami
- 1821
Camana, Ocona, Caraveli
10 Jul 1821 · 171 km away · intensity VIII
162 deathsSevere damage ($5–24M)
- 2001M8.4
Arequipa, Moquegua, Tacna, Ayacucho
23 Jun 2001 · 200 km away · intensity VIII
103 deaths$200 million damagetsunami
- 1991M4.7
Maca, Chivay, Yanque
23 Jul 1991 · 213 km away · intensity V
92 deathsModerate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.