Reviewed by USGSChile10y ago
M3.9 earthquake 66 km WNW of La Ligua, Chile
Friday, November 11, 2016, 00:11:05 UTC · 32.128°S, 71.829°W
A magnitude 3.9 earthquake struck 66 km WNW of La Ligua, Chile on Friday, November 11, 2016, 00:11:05 UTC, at a depth of 20.2 km (shallow). USGS received 1 “Did You Feel It?” report, with a maximum reported intensity of II (weak).
- Magnitude
- 3.9
- Minor · mwr
- Depth
- 20 km
- Shallow
- Felt reports
- 1
- Max intensity II
- 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
86 km
from the nearest mapped plate boundary, between the Nazca and South American plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
20 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
Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.
| Place | Intensity | Reports | Distance |
|---|---|---|---|
| Lampa, Metropolitana, Chile | II · Weak | 1 | 155 km |
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 M4.7 on December 3, 2016. 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 929 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.348 km W of Illapel, ChileSeptember 16, 2015 · 63 km N of this epicenter
- 8.2The 1906 Valparaiso, Chile EarthquakeAugust 17, 1906 · 50 km SE of this epicenter
- 8.145 km NNW of Illapel, ChileApril 6, 1943 · 106 km NE of this epicenter
- 8.025 km WSW of Valparaíso, ChileMarch 3, 1985 · 112 km S of this epicenter
- 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 82 km SE of this epicenter
- 7.47 km SSE of La Ligua, ChileMarch 28, 1965 · 73 km SE of this epicenter
- 7.419 km S of Valparaíso, ChileMarch 4, 1985 · 121 km S of this epicenter
- 7.237 km S of San Antonio, ChileMarch 18, 1931 · 202 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 52 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 18,795 recorded deaths. The most severe:
- 1861
Mendoza, San Luiz
20 Mar 1861 · 294 km away · intensity IX
14,000 deathsExtreme damage ($25M+)tsunami
- 1906M8.2
South Central
17 Aug 1906 · 98 km away · intensity XI
4,000 deaths$100 million damagetsunami
- 1965M7.3
Central
28 Mar 1965 · 66 km away
400 deaths$125 million damage
- 1985M8.0
Central Coast, San Antonio, Valparaiso
3 Mar 1985 · 112 km away · intensity VIII
180 deaths$1.5 billion damagetsunami
- 1971M7.8
Central
9 Jul 1971 · 72 km away · intensity IX
83 deaths$236 million damagetsunami
- 1822M8.5
Valparaiso, Quillota, Concon, Aconcagua
20 Nov 1822 · 98 km away · intensity XI
72 deathsExtreme damage ($25M+)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.