Reviewed by USGSChile43y ago
M4.9 earthquake 41 km SSE of Taltal, Chile
Thursday, October 6, 1983, 21:56:58 UTC · 25.749°S, 70.318°W
A magnitude 4.9 earthquake struck 41 km SSE of Taltal, Chile on Thursday, October 6, 1983, 21:56:58 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M5.5 on October 6, 1983.
- Magnitude
- 4.9
- 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
338 tons of TNT
That is about 1/45 of the Hiroshima bomb. A magnitude 5.0 releases about 1 times more energy.
Tectonic setting
129 km
from the nearest mapped plate boundary, between the Nazca and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
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 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M6.7 on October 9, 1983. 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 203 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.594 km ENE of Vallenar, ChileNovember 11, 1922 · 287 km S of this epicenter
- 8.060 km W of Diego de Almagro, ChileDecember 4, 1918 · 86 km SW of this epicenter
- 7.79 km SSW of Taltal, ChileDecember 28, 1966 · 36 km NW of this epicenter
- 7.583 km NNE of Taltal, ChileJuly 13, 1936 · 116 km N of this epicenter
- 7.550 km WNW of Diego de Almagro, ChileJune 8, 1909 · 49 km S of this epicenter
- 7.4Atacama, ChileApril 18, 1939 · 172 km S of this epicenter
- 7.454 km WSW of Diego de Almagro, ChileOctober 4, 1983 · 91 km S of this epicenter
- 7.377 km NNE of Taltal, ChileDecember 2, 1960 · 113 km N 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 722 recorded deaths. The most severe:
- 1922M8.5
Atacama
11 Nov 1922 · 287 km away · intensity XI
700 deathsSevere damage ($5–24M)tsunami
- 1859M7.6
Chile
5 Oct 1859 · 178 km away · intensity X
10 deathsUnder $1 million damagetsunami
- 1983M7.3
Northern: Copoapo-Chanaral
4 Oct 1983 · 91 km away · intensity VII
5 deaths$1 million damagetsunami
- 1966M7.8
Taltal, Catalina
28 Dec 1966 · 47 km away · intensity VIII
3 deathsUnder $1 million damagetsunami
- 1946M7.9
Northern
2 Aug 1946 · 85 km away
2 deathsSevere damage ($5–24M)tsunami
- 1936M7.3
Taltal
13 Jul 1936 · 143 km away
1 deathModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.