Reviewed by USGSArgentina107y ago
M6.7 earthquake 26 km S of Nueve de Julio, Argentina
Friday, December 17, 1920, 19:00:04 UTC · 31.905°S, 68.412°W
A magnitude 6.7 earthquake struck 26 km S of Nueve de Julio, Argentina on Friday, December 17, 1920, 19:00:04 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.9 on July 27, 1917.
- Magnitude
- 6.7
- Strong · mw
- Depth
- 15 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 earthquake
In context
How big was it, and why here?
Energy released
194 kilotons of TNT
That is about 13 times the Hiroshima bomb. It released about 407 times the energy of a magnitude 5.0.
Tectonic setting
405 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
15 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 100 km
USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 2 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 12 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 14,410 recorded deaths. The most severe:
- 1861
Mendoza, San Luiz
20 Mar 1861 · 106 km away · intensity IX
14,000 deathsExtreme damage ($25M+)tsunami
- 1920M6.7
Mendoza
17 Dec 1920 · 0 km away · intensity VIII
400 deathsSevere damage ($5–24M)
- 1730M9.1
Valparaiso
8 Jul 1730 · 298 km away · intensity XI
5 deathsSevere damage ($5–24M)tsunami
- 1903M6.0
Mendoza
12 Aug 1903 · 68 km away · intensity VIII
3 deathsModerate damage ($1–5M)
- 1880M7.7
Illapel
15 Aug 1880 · 264 km away · intensity X
2 deathsSevere damage ($5–24M)tsunami
- 1894M7.5
La Rioja, San Juan, Mendoza
27 Oct 1894 · 13 km away · intensity IX
Severe damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.