Reviewed by USGSEcuador64y ago
M6.6 earthquake 55 km ENE of Macas, Ecuador
Friday, May 10, 1963, 22:22:43 UTC · 2.188°S, 77.623°W
A magnitude 6.6 earthquake struck 55 km ENE of Macas, Ecuador on Friday, May 10, 1963, 22:22:43 UTC, at a depth of 20.0 km (shallow). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 6.6
- Strong · mw
- Depth
- 20 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VI
- 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
120 kilotons of TNT
That is about 8 times the Hiroshima bomb. It released about 251 times the energy of a magnitude 5.0.
Tectonic setting
141 km
from the nearest mapped plate boundary, between the North Andes and South American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
20 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 10 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.6119 km E of Macas, EcuadorJuly 28, 1961 · 66 km E of this epicenter
- 6.542 km SE of Cayambe, EcuadorMay 11, 1955 · 220 km N of this epicenter
- 6.522 km NE of Baños, EcuadorAugust 5, 1949 · 130 km NW of this epicenter
- 6.3128 km ESE of Palora, EcuadorJune 12, 1942 · 84 km E of this epicenter
- 6.233 km W of Ambato, EcuadorJuly 22, 1924 · 178 km NW of this epicenter
- 6.219 km SSW of Lomas de Sargentillo, EcuadorJanuary 30, 1943 · 281 km W of this epicenter
- 6.280 km ENE of Gualaquiza, EcuadorMay 25, 1958 · 120 km S of this epicenter
- 6.014 km W of Cotacachi, EcuadorJuly 20, 1955 · 290 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 19 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 117,051 recorded deaths. The most severe:
- 1868M7.7
Guayaquil,Ibarra; Colombia: San Pablo
16 Aug 1868 · 285 km away · intensity X
70,000 deathsExtreme damage ($25M+)
- 1797M8.3
Riobamba, Quito, Cuzco; Peru; Colombia
4 Feb 1797 · 131 km away · intensity XI
40,000 deathsExtreme damage ($25M+)tsunami
- 1949M6.5
Tungurahua
5 Aug 1949 · 130 km away
6,000 deaths$8 million damage
- 1757M7.0
Cotopaxi,Tungurahua, Latacunga
22 Feb 1757 · 180 km away · intensity IX
1,000 deathsSevere damage ($5–24M)
- 1924M6.9
Ecuador
3 Mar 1924 · 127 km away
40 deathsLimited damage (under $1M)
- 1960
Ecuador
30 Jul 1960 · 171 km away
11 deathsLimited damage (under $1M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.