Reviewed by USGSEcuador72y ago
M6.5 earthquake 42 km SE of Cayambe, Ecuador
Wednesday, May 11, 1955, 11:04:04 UTC · 0.230°S, 77.878°W
A magnitude 6.5 earthquake struck 42 km SE of Cayambe, Ecuador on Wednesday, May 11, 1955, 11:04:04 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.6 on October 23, 1944.
- Magnitude
- 6.5
- Strong · mw
- Depth
- 15 km
- Shallow
- 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 earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
79 kilotons of TNT
That is about 5 times the Hiroshima bomb. It released about 166 times the energy of a magnitude 5.0.
Tectonic setting
31 km
from the nearest mapped plate boundary, between the North Andes and South American plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
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 18 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.81906 Ecuador-Colombia EarthquakeJanuary 31, 1906 · 212 km NW of this epicenter
- 7.812 km SE of Pedernales, EcuadorMay 14, 1942 · 235 km W of this epicenter
- 6.813 km N of Muisne, EcuadorJune 30, 1916 · 260 km NW of this epicenter
- 6.667 km NNW of Esmeraldas, EcuadorJune 1, 1907 · 300 km NW of this epicenter
- 6.645 km ESE of Esmeraldas, EcuadorOctober 23, 1944 · 193 km NW of this epicenter
- 6.629 km SE of Pedernales, EcuadorJuly 12, 1942 · 223 km W of this epicenter
- 6.537 km SSW of La Tola, ColombiaJune 5, 1907 · 263 km N of this epicenter
- 6.522 km NE of Baños, EcuadorAugust 5, 1949 · 122 km SW 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 118,850 recorded deaths. The most severe:
- 1868M7.7
Guayaquil,Ibarra; Colombia: San Pablo
16 Aug 1868 · 69 km away · intensity X
70,000 deathsExtreme damage ($25M+)
- 1797M8.3
Riobamba, Quito, Cuzco; Peru; Colombia
4 Feb 1797 · 180 km away · intensity XI
40,000 deathsExtreme damage ($25M+)tsunami
- 1949M6.5
Tungurahua
5 Aug 1949 · 122 km away
6,000 deaths$8 million damage
- 1906M8.8
Off Coast
31 Jan 1906 · 212 km away · intensity IX
1,000 deathsSevere damage ($5–24M)tsunami
- 1757M7.0
Cotopaxi,Tungurahua, Latacunga
22 Feb 1757 · 110 km away · intensity IX
1,000 deathsSevere damage ($5–24M)
- 1923M6.2
Ipiales
14 Dec 1923 · 123 km away · intensity IX
300 deathsModerate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.