Reviewed by USGSArgentina110y ago
M6.9 earthquake 72 km WNW of Calingasta, Argentina
Friday, July 27, 1917, 02:51:50 UTC · 30.984°S, 70.062°W
A magnitude 6.9 earthquake struck 72 km WNW of Calingasta, Argentina on Friday, July 27, 1917, 02:51:50 UTC, at a depth of 115.0 km (intermediate). It is the strongest earthquake within 300 km since an M6.9 on February 15, 1917.
- Magnitude
- 6.9
- Strong · mB
- Depth
- 115 km
- Intermediate
- 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
338 kilotons of TNT
That is about 22 times the Hiroshima bomb. It released about 708 times the energy of a magnitude 5.0.
Tectonic setting
244 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: intermediate
115 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 5 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 · 202 km SW of this epicenter
- 7.086 km NW of La Serena, ChileMarch 19, 1904 · 251 km NW of this epicenter
- 6.957 km W of Ovalle, ChileFebruary 15, 1917 · 173 km W of this epicenter
- 6.358 km WNW of La Ligua, ChileOctober 2, 1906 · 209 km SW of this epicenter
- 6.3137 km WNW of Coquimbo, ChileNovember 28, 1906 · 297 km NW 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 18,082 recorded deaths. The most severe:
- 1861
Mendoza, San Luiz
20 Mar 1861 · 234 km away · intensity IX
14,000 deathsExtreme damage ($25M+)tsunami
- 1906M8.2
South Central
17 Aug 1906 · 289 km away · intensity XI
4,000 deaths$100 million damagetsunami
- 1822M8.5
Valparaiso, Quillota, Concon, Aconcagua
20 Nov 1822 · 289 km away · intensity XI
72 deathsExtreme damage ($25M+)tsunami
- 1730M9.1
Valparaiso
8 Jul 1730 · 217 km away · intensity XI
5 deathsSevere damage ($5–24M)tsunami
- 1903M6.0
Mendoza
12 Aug 1903 · 154 km away · intensity VIII
3 deathsModerate damage ($1–5M)
- 1880M7.7
Illapel
15 Aug 1880 · 128 km away · intensity X
2 deathsSevere damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.