Reviewed by USGSChile28y ago
M4.4 earthquake 17 km N of Illapel, Chile
Wednesday, January 27, 1999, 11:57:14 UTC · 31.481°S, 71.190°W
A magnitude 4.4 earthquake struck 17 km N of Illapel, Chile on Wednesday, January 27, 1999, 11:57:14 UTC, at a depth of 33.0 km (shallow).
- Magnitude
- 4.4
- Light · md
- 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
60 tons of TNT
That is about 1/251 of the Hiroshima bomb. A magnitude 5.0 releases about 8 times more energy.
Tectonic setting
140 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M3.9 on February 10, 1999. 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 513 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 · 104 km S of this epicenter
- 8.145 km NNW of Illapel, ChileApril 6, 1943 · 30 km NW of this epicenter
- 8.025 km WSW of Valparaíso, ChileMarch 3, 1985 · 195 km S of this epicenter
- 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 126 km S of this epicenter
- 7.47 km SSE of La Ligua, ChileMarch 28, 1965 · 115 km S of this epicenter
- 7.419 km S of Valparaíso, ChileMarch 4, 1985 · 197 km S of this epicenter
- 7.237 km S of San Antonio, ChileMarch 18, 1931 · 274 km S of this epicenter
- 7.259 km S of San Antonio, ChileApril 9, 1985 · 297 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 51 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 29,189 recorded deaths. The most severe:
- 1861
Mendoza, San Luiz
20 Mar 1861 · 269 km away · intensity IX
14,000 deathsExtreme damage ($25M+)tsunami
- 1944M6.9
San Juan Province
15 Jan 1944 · 256 km away · intensity IX
10,000 deaths$100 million damage
- 1906M8.2
South Central
17 Aug 1906 · 185 km away · intensity XI
4,000 deaths$100 million damagetsunami
- 1965M7.3
Central
28 Mar 1965 · 102 km away
400 deaths$125 million damage
- 1920M6.7
Mendoza
17 Dec 1920 · 267 km away · intensity VIII
400 deathsSevere damage ($5–24M)
- 1985M8.0
Central Coast, San Antonio, Valparaiso
3 Mar 1985 · 190 km away · intensity VIII
180 deaths$1.5 billion damagetsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.