Reviewed by USGSArgentina19y ago
M4.6 earthquake 68 km WSW of San Antonio de los Cobres, Argentina
Wednesday, March 21, 2007, 19:08:24 UTC · 24.434°S, 66.955°W
A magnitude 4.6 earthquake struck 68 km WSW of San Antonio de los Cobres, Argentina on Wednesday, March 21, 2007, 19:08:24 UTC, at a depth of 150.0 km (intermediate). It is the strongest earthquake within 300 km since an M4.7 on March 8, 2007.
- Magnitude
- 4.6
- Light · mb
- Depth
- 150 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 earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
324 km
from the nearest mapped plate boundary, between the Altiplano and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
150 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 50 km
USGS lists 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.9 on April 9, 2007. 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 357 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.2121 km SSE of San Pedro de Atacama, ChileDecember 9, 1950 · 110 km NW of this epicenter
- 7.275 km N of San Antonio de los Cobres, ArgentinaMay 12, 2000 · 111 km NE of this epicenter
- 7.116 km NW of Villazón, BoliviaJanuary 23, 1997 · 299 km NE of this epicenter
- 7.087 km W of Abra Pampa, ArgentinaMay 24, 1993 · 200 km N of this epicenter
- 7.052 km W of Abra Pampa, ArgentinaApril 1, 1987 · 200 km NE of this epicenter
- 6.930 km SSE of Santa Clara, ArgentinaAugust 25, 1948 · 247 km E of this epicenter
- 6.999 km WNW of San Antonio de los Cobres, ArgentinaFebruary 21, 1971 · 76 km N of this epicenter
- 6.840 km SE of San Pedro de Atacama, ChileAugust 3, 1962 · 171 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 33 recorded deaths. The most severe:
- 1930M6.1
La Poma
24 Dec 1930 · 172 km away · intensity VIII
31 deathsSevere damage ($5–24M)
- 1971M6.3
Catalina, Antofagasta
17 Jun 1971 · 255 km away · intensity V
1 deathModerate damage ($1–5M)
- 1950M8.0
Chile-Argentina
9 Dec 1950 · 118 km away · intensity VII
1 death
- 1844M6.5
Salta, Jujuy, Tucuman
19 Oct 1844 · 115 km away · intensity VII
Severe damage ($5–24M)
- 1948M6.9
Salta
25 Aug 1948 · 247 km away · intensity IX
Moderate damage ($1–5M)
- 1959M6.6
Salta
12 May 1959 · 258 km away · intensity VIII
Moderate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.