Reviewed by USGSArgentina39y ago
M3.9 earthquake 72 km W of La Quiaca, Argentina
Sunday, April 26, 1987, 04:01:44 UTC · 22.150°S, 66.294°W
A magnitude 3.9 earthquake struck 72 km W of La Quiaca, Argentina on Sunday, April 26, 1987, 04:01:44 UTC, at a depth of 319.3 km (deep).
- Magnitude
- 3.9
- Minor · mb
- Depth
- 319 km
- Deep
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquake
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
72 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: deep
319 km
Deep earthquakes (over 300 km) happen deep inside subducting plates. They rarely cause damage, but can be felt faintly over very large distances.
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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 222 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.2121 km SSE of San Pedro de Atacama, ChileDecember 9, 1950 · 262 km SW of this epicenter
- 7.751 km W of Atocha, BoliviaNovember 29, 1957 · 141 km N of this epicenter
- 7.278 km SW of Colchani, BoliviaOctober 4, 1910 · 203 km NW of this epicenter
- 7.069 km NW of Camargo, BoliviaMay 17, 1909 · 215 km N of this epicenter
- 7.052 km W of Abra Pampa, ArgentinaApril 1, 1987 · 69 km S of this epicenter
- 6.999 km WNW of San Antonio de los Cobres, ArgentinaFebruary 21, 1971 · 203 km SW of this epicenter
- 6.840 km SE of San Pedro de Atacama, ChileAugust 3, 1962 · 201 km SW of this epicenter
- 6.7136 km NNE of Calama, ChileDecember 27, 1967 · 226 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 15 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 5 recorded deaths. The most severe:
- 1953M7.4
Northern
7 Dec 1953 · 248 km away
3 deaths$7 million damage
- 1959M7.5
Bolivia-Northern Chile
14 Jun 1959 · 265 km away
1 deathLimited damage (under $1M)
- 1950M8.0
Chile-Argentina
9 Dec 1950 · 194 km away · intensity VII
1 death
- 1899M6.9
Southern; Argentina: Salta
23 Mar 1899 · 271 km away · intensity X
Moderate damage ($1–5M)
- 1959M6.6
Salta
12 May 1959 · 175 km away · intensity VIII
Moderate damage ($1–5M)
- 1863
Jujuy
14 Jan 1863 · 209 km away · intensity VIII
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.