Reviewed by USGSChile16y ago
M4.3 earthquake 46 km WSW of Santa Cruz, Chile
Sunday, July 4, 2010, 09:53:11 UTC · 34.758°S, 71.857°W
A magnitude 4.3 earthquake struck 46 km WSW of Santa Cruz, Chile on Sunday, July 4, 2010, 09:53:11 UTC, at a depth of 35.0 km (shallow).
- Magnitude
- 4.3
- Light · mb
- Depth
- 35 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
43 tons of TNT
That is about 1/354 of the Hiroshima bomb. A magnitude 5.0 releases about 11 times more energy.
Tectonic setting
136 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
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
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 4 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.7 on July 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 641 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.82010 Maule, Chile EarthquakeFebruary 27, 2010 · 179 km SW of this epicenter
- 8.2The 1906 Valparaiso, Chile EarthquakeAugust 17, 1906 · 266 km N of this epicenter
- 8.025 km WSW of Valparaíso, ChileMarch 3, 1985 · 180 km N of this epicenter
- 7.826 km WNW of San Carlos, ChileJanuary 25, 1939 · 174 km S of this epicenter
- 7.819 km NNE of Hacienda La Calera, ChileJuly 9, 1971 · 246 km N of this epicenter
- 7.730 km NNE of Constitución, ChileDecember 1, 1928 · 52 km SW of this epicenter
- 7.7103 km NW of Constitución, ChileJanuary 30, 1914 · 133 km W of this epicenter
- 7.523 km SE of Chiguayante, ChileMay 6, 1953 · 275 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 42 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 35,721 recorded deaths. The most severe:
- 1939M8.3
Chillan
25 Jan 1939 · 170 km away · intensity X
30,000 deaths$920 million damagetsunami
- 1906M8.2
South Central
17 Aug 1906 · 196 km away · intensity XI
4,000 deaths$100 million damagetsunami
- 2010M8.8
Maule, Concepcion, Talcahuano
27 Feb 2010 · 179 km away · intensity IX
558 deaths$30 billion damagetsunami
- 1965M7.3
Central
28 Mar 1965 · 269 km away
400 deaths$125 million damage
- 1928M7.6
Talca, Chillan, Santiago, San Fernando
1 Dec 1928 · 30 km away · intensity IX
279 deathsSevere damage ($5–24M)tsunami
- 1985M8.0
Central Coast, San Antonio, Valparaiso
3 Mar 1985 · 181 km away · intensity VIII
180 deaths$1.5 billion damagetsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.