Reviewed by USGSChile16y ago
M4.2 earthquake 85 km NNW of Talcahuano, Chile
Thursday, April 22, 2010, 21:20:17 UTC · 36.086°S, 73.642°W
A magnitude 4.2 earthquake struck 85 km NNW of Talcahuano, Chile on Thursday, April 22, 2010, 21:20:17 UTC, at a depth of 30.0 km (shallow).
- Magnitude
- 4.2
- Light · mb
- Depth
- 30 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
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
46 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
30 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 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.7 on May 8, 2010. 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 493 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 9.51960 Great Chilean Earthquake (Valdivia Earthquake)May 22, 1960 · 230 km S of this epicenter
- 8.82010 Maule, Chile EarthquakeFebruary 27, 2010 · 67 km E of this epicenter
- 8.14 km ESE of Cañete, ChileMay 21, 1960 · 195 km S of this epicenter
- 7.826 km WNW of San Carlos, ChileJanuary 25, 1939 · 130 km E of this epicenter
- 7.838 km WNW of Traiguén, ChileMay 22, 1960 · 226 km S of this epicenter
- 7.730 km NNE of Constitución, ChileDecember 1, 1928 · 167 km NE of this epicenter
- 7.744 km SSE of Cañete, ChileMay 10, 1975 · 236 km S of this epicenter
- 7.7103 km NW of Constitución, ChileJanuary 30, 1914 · 150 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 26 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 33,255 recorded deaths. The most severe:
- 1939M8.3
Chillan
25 Jan 1939 · 126 km away · intensity X
30,000 deaths$920 million damagetsunami
- 1960M9.5
Puerto Montt, Valdivia
22 May 1960 · 230 km away · intensity XII
2,226 deaths$1.0 billion damagetsunami
- 2010M8.8
Maule, Concepcion, Talcahuano
27 Feb 2010 · 67 km away · intensity IX
558 deaths$30 billion damagetsunami
- 1928M7.6
Talca, Chillan, Santiago, San Fernando
1 Dec 1928 · 191 km away · intensity IX
279 deathsSevere damage ($5–24M)tsunami
- 1751M8.5
Concepcion, Chillan, Talca, Tutuben, Curico
25 May 1751 · 198 km away · intensity XI
65 deathsSevere damage ($5–24M)tsunami
- 1949M7.3
Angol, Traiguen
20 Apr 1949 · 213 km away
57 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.