Reviewed by USGSEcuador56y ago
M6.7 earthquake 37 km E of Palora, Ecuador
Monday, May 17, 1971, 11:04:08 UTC · 1.637°S, 77.638°W
A magnitude 6.7 earthquake struck 37 km E of Palora, Ecuador on Monday, May 17, 1971, 11:04:08 UTC, at a depth of 171.2 km (intermediate). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.
- Magnitude
- 6.7
- Strong · mw
- Depth
- 171 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- V
- Moderate (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
163 kilotons of TNT
That is about 11 times the Hiroshima bomb. It released about 343 times the energy of a magnitude 5.0.
Tectonic setting
116 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: intermediate
171 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 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 33 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.655 km ENE of Macas, EcuadorMay 10, 1963 · 61 km S of this epicenter
- 6.6119 km E of Macas, EcuadorJuly 28, 1961 · 99 km SE of this epicenter
- 6.629 km SE of Pedernales, EcuadorJuly 12, 1942 · 300 km NW of this epicenter
- 6.558 km E of Puyo, EcuadorSeptember 17, 1965 · 28 km NE of this epicenter
- 6.542 km SE of Cayambe, EcuadorMay 11, 1955 · 159 km N of this epicenter
- 6.522 km NE of Baños, EcuadorAugust 5, 1949 · 86 km NW of this epicenter
- 6.328 km WNW of El Ángel, EcuadorDecember 14, 1923 · 266 km N of this epicenter
- 6.3128 km ESE of Palora, EcuadorJune 12, 1942 · 98 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 23 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 117,352 recorded deaths. The most severe:
- 1868M7.7
Guayaquil,Ibarra; Colombia: San Pablo
16 Aug 1868 · 225 km away · intensity X
70,000 deathsExtreme damage ($25M+)
- 1797M8.3
Riobamba, Quito, Cuzco; Peru; Colombia
4 Feb 1797 · 115 km away · intensity XI
40,000 deathsExtreme damage ($25M+)tsunami
- 1949M6.5
Tungurahua
5 Aug 1949 · 86 km away
6,000 deaths$8 million damage
- 1757M7.0
Cotopaxi,Tungurahua, Latacunga
22 Feb 1757 · 135 km away · intensity IX
1,000 deathsSevere damage ($5–24M)
- 1923M6.2
Ipiales
14 Dec 1923 · 279 km away · intensity IX
300 deathsModerate damage ($1–5M)
- 1924M6.9
Ecuador
3 Mar 1924 · 107 km away
40 deathsLimited damage (under $1M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.