Reviewed by USGSChile21y ago
M3.9 earthquake 36 km ESE of Calama, Chile
Monday, November 21, 2005, 21:50:32 UTC · 22.632°S, 68.628°W
A magnitude 3.9 earthquake struck 36 km ESE of Calama, Chile on Monday, November 21, 2005, 21:50:32 UTC, at a depth of 129.2 km (intermediate).
- Magnitude
- 3.9
- Minor · mb
- Depth
- 129 km
- Intermediate
- 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
125 km
from the nearest mapped plate boundary, between the Altiplano and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
129 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 50 km
USGS lists 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.2 on December 5, 2005. 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 678 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 · 166 km SE of this epicenter
- 8.036 km NNE of Antofagasta, ChileJuly 30, 1995 · 188 km SW of this epicenter
- 7.8102 km ENE of Iquique, ChileJune 13, 2005 · 300 km N of this epicenter
- 7.751 km W of Atocha, BoliviaNovember 29, 1957 · 272 km NE of this epicenter
- 7.684 km SSE of Antofagasta, ChileMarch 5, 1987 · 250 km SW of this epicenter
- 7.583 km NNE of Taltal, ChileJuly 13, 1936 · 279 km SW of this epicenter
- 7.334 km NE of Tocopilla, ChileDecember 21, 1967 · 160 km NW of this epicenter
- 7.377 km NNE of Taltal, ChileDecember 2, 1960 · 289 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 26 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,408 recorded deaths. The most severe:
- 1877M8.3
Off North Coast
10 May 1877 · 230 km away · intensity XI
2,385 deaths$2 million damagetsunami
- 2005M7.7
Tarapaca
13 Jun 2005 · 300 km away
11 deaths$5 million damage
- 1953M7.4
Northern
7 Dec 1953 · 60 km away
3 deaths$7 million damage
- 1995M8.0
Antofagasta, Calama, Mejillones
30 Jul 1995 · 188 km away · intensity VII
3 deaths$2 million damagetsunami
- 1967M7.5
Northern
21 Dec 1967 · 137 km away
1 deathModerate damage ($1–5M)tsunami
- 1936M7.3
Taltal
13 Jul 1936 · 250 km away
1 deathModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.