Reviewed by USGSPeru44y ago
M6.9 earthquake 77 km SE of Palca, Peru
Friday, February 25, 1983, 22:49:54 UTC · 18.268°S, 69.438°W
A magnitude 6.9 earthquake struck 77 km SE of Palca, Peru on Friday, February 25, 1983, 22:49:54 UTC, at a depth of 146.0 km (intermediate). It is the strongest earthquake within 300 km since an M7.1 on June 14, 1959.
- Magnitude
- 6.9
- Strong · mw
- Depth
- 146 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VI
- Strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
338 kilotons of TNT
That is about 22 times the Hiroshima bomb. It released about 708 times the energy of a magnitude 5.0.
Tectonic setting
270 km
from the nearest mapped plate boundary, between the Nazca and Altiplano plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
146 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 100 km
USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 137 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.3136 km WSW of Challapata, BoliviaJune 6, 1915 · 185 km SE of this epicenter
- 7.334 km S of Iquique, ChileFebruary 23, 1933 · 263 km S of this epicenter
- 7.2Near the coast of Tarapaca, ChileOctober 4, 1940 · 217 km SW of this epicenter
- 7.1136 km E of Iquique, ChileJune 14, 1959 · 245 km S of this epicenter
- 6.9119 km W of Iquique, ChileSeptember 15, 1911 · 288 km SW of this epicenter
- 6.925 km ENE of Arica, ChileAugust 30, 1906 · 70 km W of this epicenter
- 6.987 km NNW of Iquique, ChileDecember 26, 1906 · 188 km SW of this epicenter
- 6.739 km NNW of Colchane, ChileAugust 20, 1965 · 101 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 38 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 25,703 recorded deaths. The most severe:
- 1868M8.5
Arica
13 Aug 1868 · 169 km away · intensity XI
25,000 deaths$300 million damagetsunami
- 1833M7.7
Peru: Tacna; Chile: Arica
18 Sep 1833 · 166 km away · intensity VIII
700 deathsSevere damage ($5–24M)tsunami
- 1976M7.3
Pozo Almonte, Oficina Victoria, Arica
30 Nov 1976 · 256 km away · intensity VIII
1 deathModerate damage ($1–5M)
- 1948M6.5
Arequipa,Moquegua,Tacna,Torata,Quellaveco
11 May 1948 · 146 km away · intensity IX
1 deathModerate damage ($1–5M)
- 1959M7.5
Bolivia-Northern Chile
14 Jun 1959 · 278 km away
1 deathLimited damage (under $1M)
- 1878M7.9
Tarapaca
23 Jan 1878 · 206 km away · intensity VIII
Severe damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.