Reviewed by USGSChile99y ago
M5.5 earthquake 10 km NNE of Cauquenes, Chile
Saturday, December 8, 1928, 13:23:37 UTC · 35.872°S, 72.295°W
A magnitude 5.5 earthquake struck 10 km NNE of Cauquenes, Chile on Saturday, December 8, 1928, 13:23:37 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M5.5 on December 2, 1928.
- Magnitude
- 5.5
- Moderate · mw
- 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: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
3 kilotons of TNT
That is about 1/6 of the Hiroshima bomb. It released about 5 times the energy of a magnitude 5.0.
Tectonic setting
148 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 75 km
USGS lists 1 M2.5+ earthquake within 75 km in the following 30 days; the largest was M5.7 on December 20, 1928. 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 17 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.730 km NNE of Constitución, ChileDecember 1, 1928 · 88 km N of this epicenter
- 7.7103 km NW of Constitución, ChileJanuary 30, 1914 · 154 km NW of this epicenter
- 7.247 km NW of Cauquenes, ChileDecember 2, 1928 · 44 km NW of this epicenter
- 7.019 km SW of Angol, ChileAugust 20, 1920 · 233 km S of this epicenter
- 6.599 km SE of Rengo, ChileJanuary 30, 1914 · 233 km NE of this epicenter
- 6.3210 km WNW of Constitución, ChileSeptember 6, 1926 · 246 km NW of this epicenter
- 6.213 km S of Constitución, ChileDecember 1, 1928 · 48 km N of this epicenter
- 6.1187 km NW of Constitución, ChileMay 21, 1922 · 241 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 403 recorded deaths. The most severe:
- 1928M7.6
Talca, Chillan, Santiago, San Fernando
1 Dec 1928 · 101 km away · intensity IX
279 deathsSevere damage ($5–24M)tsunami
- 1751M8.5
Concepcion, Chillan, Talca, Tutuben, Curico
25 May 1751 · 122 km away · intensity XI
65 deathsSevere damage ($5–24M)tsunami
- 1835M8.2
Concepcion
20 Feb 1835 · 125 km away · intensity XI
53 deathsExtreme damage ($25M+)tsunami
- 1898M6.5
Concepcion
23 Jul 1898 · 125 km away · intensity VIII
6 deathsModerate damage ($1–5M)tsunami
- 1871M7.5
Central
25 Mar 1871 · 99 km away
Severe damage ($5–24M)tsunami
- 1851M7.1
Valparaiso
2 Apr 1851 · 295 km away · intensity VIII
Severe damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.