Reviewed by USGSChile28y ago
M4.1 earthquake 102 km W of Illapel, Chile
Wednesday, January 6, 1999, 16:16:53 UTC · 31.752°S, 72.237°W
A magnitude 4.1 earthquake struck 102 km W of Illapel, Chile on Wednesday, January 6, 1999, 16:16:53 UTC, at a depth of 21.4 km (shallow).
- Magnitude
- 4.1
- Light · md
- Depth
- 21 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
21 tons of TNT
That is about 1/707 of the Hiroshima bomb. A magnitude 5.0 releases about 22 times more energy.
Tectonic setting
44 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
21 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 6 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.2 on February 3, 1999. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.062 km WSW of Illapel, Chile28y ago · 41 km E of this epicenter
- 4.2132 km WSW of Illapel, Chile28y ago · 32 km SW of this epicenter
- 3.865 km W of Illapel, Chile28y ago · 39 km E of this epicenter
- 4.297 km W of Illapel, Chile28y ago · 5 km E of this epicenter
- 3.757 km WSW of Illapel, Chile28y ago · 46 km E of this epicenter
- 3.9113 km W of Illapel, Chile28y ago · 11 km W of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 462 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.2The 1906 Valparaiso, Chile EarthquakeAugust 17, 1906 · 107 km SE of this epicenter
- 8.145 km NNW of Illapel, ChileApril 6, 1943 · 99 km NE of this epicenter
- 8.025 km WSW of Valparaíso, ChileMarch 3, 1985 · 158 km S of this epicenter
- 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 139 km SE of this epicenter
- 7.47 km SSE of La Ligua, ChileMarch 28, 1965 · 129 km SE of this epicenter
- 7.419 km S of Valparaíso, ChileMarch 4, 1985 · 171 km S of this epicenter
- 7.237 km S of San Antonio, ChileMarch 18, 1931 · 250 km S of this epicenter
- 7.259 km S of San Antonio, ChileApril 9, 1985 · 271 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 40 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 4,771 recorded deaths. The most severe:
- 1906M8.2
South Central
17 Aug 1906 · 141 km away · intensity XI
4,000 deaths$100 million damagetsunami
- 1965M7.3
Central
28 Mar 1965 · 121 km away
400 deaths$125 million damage
- 1985M8.0
Central Coast, San Antonio, Valparaiso
3 Mar 1985 · 161 km away · intensity VIII
180 deaths$1.5 billion damagetsunami
- 1971M7.8
Central
9 Jul 1971 · 128 km away · intensity IX
83 deaths$236 million damagetsunami
- 1822M8.5
Valparaiso, Quillota, Concon, Aconcagua
20 Nov 1822 · 141 km away · intensity XI
72 deathsExtreme damage ($25M+)tsunami
- 1943M8.2
Illapel
6 Apr 1943 · 114 km away
11 deathsLimited damage (under $1M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.