Reviewed by USGSChile10y ago
M4.6 earthquake 42 km WNW of Illapel, Chile
Monday, July 4, 2016, 00:13:03 UTC · 31.443°S, 71.556°W
A magnitude 4.6 earthquake struck 42 km WNW of Illapel, Chile on Monday, July 4, 2016, 00:13:03 UTC, at a depth of 44.0 km (shallow). USGS received 1 “Did You Feel It?” report, with a maximum reported intensity of II (weak). It is the strongest earthquake within 300 km since an M4.6 on July 1, 2016.
- Magnitude
- 4.6
- Light · mwr
- Depth
- 44 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
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
105 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
44 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 |
|---|---|---|---|
| Monte Patria, Coquimbo, Chile | II · Weak | 1 | 110 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 4 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.6 on July 29, 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 886 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 · 18 km SW of this epicenter
- 8.2The 1906 Valparaiso, Chile EarthquakeAugust 17, 1906 · 107 km S of this epicenter
- 8.145 km NNW of Illapel, ChileApril 6, 1943 · 27 km NE of this epicenter
- 8.025 km WSW of Valparaíso, ChileMarch 3, 1985 · 190 km S of this epicenter
- 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 136 km S of this epicenter
- 7.47 km SSE of La Ligua, ChileMarch 28, 1965 · 124 km S 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 57 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 28,800 recorded deaths. The most severe:
- 1861
Mendoza, San Luiz
20 Mar 1861 · 300 km away · intensity IX
14,000 deathsExtreme damage ($25M+)tsunami
- 1944M6.9
San Juan Province
15 Jan 1944 · 291 km away · intensity IX
10,000 deaths$100 million damage
- 1906M8.2
South Central
17 Aug 1906 · 178 km away · intensity XI
4,000 deaths$100 million damagetsunami
- 1965M7.3
Central
28 Mar 1965 · 112 km away
400 deaths$125 million damage
- 1985M8.0
Central Coast, San Antonio, Valparaiso
3 Mar 1985 · 188 km away · intensity VIII
180 deaths$1.5 billion damagetsunami
- 1971M7.8
Central
9 Jul 1971 · 122 km away · intensity IX
83 deaths$236 million damagetsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.