Reviewed by USGS77y ago
M7.5 earthquake in Costa Rica
Thursday, October 5, 1950, 16:09:42 UTC · 10.481°N, 85.046°W
A magnitude 7.5 earthquake struck in Costa Rica on Thursday, October 5, 1950, 16:09:42 UTC, at a depth of 97.9 km (intermediate). It is the strongest earthquake within 300 km since an M7.6 on December 21, 1939.
- Magnitude
- 7.5
- Major · mw
- Depth
- 98 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
2.7 megatons of TNT
That is about 178 times the Hiroshima bomb. It released about 5,623 times the energy of a magnitude 5.0.
Tectonic setting
17 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: intermediate
98 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 200 km
USGS lists 1 M2.5+ earthquake within 200 km in the following 30 days; the largest was M5.7 on October 17, 1950. 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 51 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.64 km WNW of Atenas, Costa RicaDecember 21, 1939 · 88 km SE of this epicenter
- 7.570 km WSW of Golfito, Costa RicaDecember 5, 1941 · 282 km SE of this epicenter
- 7.392 km SW of San Juan del Sur, NicaraguaDecember 30, 1907 · 159 km W of this epicenter
- 7.353 km SSE of Quepos, Costa RicaDecember 20, 1904 · 202 km SE of this epicenter
- 7.3204 km WSW of Sámara, Costa RicaFebruary 27, 1916 · 276 km SW of this epicenter
- 7.16 km WNW of Siquirres, Costa RicaApril 24, 1916 · 167 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 30 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 1,706 recorded deaths. The most severe:
- 1930
Managua
31 Mar 1930 · 220 km away
1,000 deaths$15 million damage
- 1910M6.4
Cartago, San Jose
4 May 1910 · 126 km away
700 deathsSevere damage ($5–24M)
- 1941M7.6
Costa Rica-Panama
5 Dec 1941 · 283 km away · intensity IV
6 deathsModerate damage ($1–5M)tsunami
- 1925M6.7
Managua
5 Oct 1925 · 192 km away
Severe damage ($5–24M)
- 1922M6.4
Nicaragua
16 Feb 1922 · 146 km away
Severe damage ($5–24M)
- 1885
Leon,Chinandega,Managua
12 Oct 1885 · 278 km away · intensity IX
Severe damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.