Reviewed by USGSChile10y ago
M4.2 earthquake 70 km WNW of Illapel, Chile
Sunday, April 17, 2016, 19:24:42 UTC · 31.457°S, 71.884°W
A magnitude 4.2 earthquake struck 70 km WNW of Illapel, Chile on Sunday, April 17, 2016, 19:24:42 UTC, at a depth of 35.0 km (shallow). USGS received 1 “Did You Feel It?” report, with a maximum reported intensity of III (weak).
- Magnitude
- 4.2
- Light · mb
- Depth
- 35 km
- Shallow
- Felt reports
- 1
- Max intensity III
- 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
30 tons of TNT
That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.
Tectonic setting
75 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
35 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 |
|---|---|---|---|
| Illapel, Coquimbo, Chile | III · Weak | 1 | 78 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 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.4 on May 17, 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 862 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 · 24 km SE of this epicenter
- 8.2The 1906 Valparaiso, Chile EarthquakeAugust 17, 1906 · 114 km SE of this epicenter
- 8.145 km NNW of Illapel, ChileApril 6, 1943 · 54 km NE of this epicenter
- 8.025 km WSW of Valparaíso, ChileMarch 3, 1985 · 187 km S of this epicenter
- 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 146 km SE of this epicenter
- 7.47 km SSE of La Ligua, ChileMarch 28, 1965 · 134 km SE of this epicenter
- 7.419 km S of Valparaíso, ChileMarch 4, 1985 · 196 km S of this epicenter
- 7.237 km S of San Antonio, ChileMarch 18, 1931 · 276 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 49 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 4,788 recorded deaths. The most severe:
- 1906M8.2
South Central
17 Aug 1906 · 172 km away · intensity XI
4,000 deaths$100 million damagetsunami
- 1965M7.3
Central
28 Mar 1965 · 123 km away
400 deaths$125 million damage
- 1985M8.0
Central Coast, San Antonio, Valparaiso
3 Mar 1985 · 187 km away · intensity VIII
180 deaths$1.5 billion damagetsunami
- 1971M7.8
Central
9 Jul 1971 · 133 km away · intensity IX
83 deaths$236 million damagetsunami
- 1822M8.5
Valparaiso, Quillota, Concon, Aconcagua
20 Nov 1822 · 172 km away · intensity XI
72 deathsExtreme damage ($25M+)tsunami
- 2015M8.3
Central
16 Sep 2015 · 24 km away · intensity IX
15 deaths$600 million damagetsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.