Reviewed by USGSCosta Rica14y ago
M4.2 earthquake 17 km WSW of Juntas, Costa Rica
Wednesday, September 26, 2012, 11:37:27 UTC · 10.218°N, 85.110°W
A magnitude 4.2 earthquake struck 17 km WSW of Juntas, Costa Rica on Wednesday, September 26, 2012, 11:37:27 UTC, at a depth of 57.1 km (shallow).
- Magnitude
- 4.2
- Light · mb
- Depth
- 57 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
30 tons of TNT
That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.
Tectonic setting
47 km
from the nearest mapped plate boundary, between the Panama and Caribbean plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
57 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 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M6.5 on October 24, 2012. 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 423 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.783 km SSW of Corinto, NicaraguaSeptember 2, 1992 · 297 km NW of this epicenter
- 7.611 km ENE of Hojancha, Costa RicaSeptember 5, 2012 · 27 km SW of this epicenter
- 7.634 km S of Limón, Costa RicaApril 22, 1991 · 231 km E of this epicenter
- 7.64 km WNW of Atenas, Costa RicaDecember 21, 1939 · 81 km E of this epicenter
- 7.5Costa RicaOctober 5, 1950 · 30 km N of this epicenter
- 7.570 km WSW of Golfito, Costa RicaDecember 5, 1941 · 261 km SE of this epicenter
- 7.37 km SSE of Puntarenas, Costa RicaMarch 25, 1990 · 47 km SE of this epicenter
- 7.392 km SW of San Juan del Sur, NicaraguaDecember 30, 1907 · 159 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 54 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 11,913 recorded deaths. The most severe:
- 1972M6.2
Managua
23 Dec 1972 · 266 km away
10,000 deaths$3.0 billion damage
- 1930
Managua
31 Mar 1930 · 241 km away
1,000 deaths$15 million damage
- 1910M6.4
Cartago, San Jose
4 May 1910 · 124 km away
700 deathsSevere damage ($5–24M)
- 1991M7.6
Limon, Pandora; Panama
22 Apr 1991 · 231 km away · intensity X
90 deaths$510 million damagetsunami
- 1952
Costa Rica
30 Dec 1952 · 176 km away
29 deaths
- 1973M6.5
Tilaran, Arenal, Rio Chiquito
14 Apr 1973 · 64 km away
26 deathsUnder $1 million damage
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.