Reviewed by USGSEcuador40y ago
M4.7 earthquake 26 km WSW of Machachi, Ecuador
Monday, March 9, 1987, 09:25:28 UTC · 0.561°S, 78.797°W
A magnitude 4.7 earthquake struck 26 km WSW of Machachi, Ecuador on Monday, March 9, 1987, 09:25:28 UTC, at a depth of 10.0 km (shallow). It is the strongest earthquake within 300 km since an M4.7 on March 7, 1987.
- Magnitude
- 4.7
- Light · mb
- Depth
- 10 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 earthquake
In context
How big was it, and why here?
Energy released
169 tons of TNT
That is about 1/89 of the Hiroshima bomb. A magnitude 5.0 releases about 3 times more energy.
Tectonic setting
45 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
10 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 127 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 · 180 km N of this epicenter
- 7.812 km SE of Pedernales, EcuadorMay 14, 1942 · 145 km NW of this epicenter
- 7.756 km NW of Valdez, EcuadorDecember 12, 1979 · 248 km N of this epicenter
- 7.6near the coast of EcuadorJanuary 19, 1958 · 191 km NW of this epicenter
- 7.498 km ESE of Sucúa, EcuadorJuly 27, 1971 · 299 km SE of this epicenter
- 7.229 km SSE of Pimampiro, EcuadorMarch 6, 1987 · 134 km NE of this epicenter
- 7.07 km NNE of Tosagua, EcuadorJanuary 16, 1956 · 159 km W of this epicenter
- 6.951 km NW of Valdez, EcuadorFebruary 1, 1958 · 241 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 40 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 124,347 recorded deaths. The most severe:
- 1868M7.7
Guayaquil,Ibarra; Colombia: San Pablo
16 Aug 1868 · 119 km away · intensity X
70,000 deathsExtreme damage ($25M+)
- 1797M8.3
Riobamba, Quito, Cuzco; Peru; Colombia
4 Feb 1797 · 121 km away · intensity XI
40,000 deathsExtreme damage ($25M+)tsunami
- 1949M6.5
Tungurahua
5 Aug 1949 · 93 km away
6,000 deaths$8 million damage
- 1987M7.2
Napo Province, Quito, Tulcan
6 Mar 1987 · 133 km away
5,000 deaths$1.5 billion damage
- 1906M8.8
Off Coast
31 Jan 1906 · 180 km away · intensity IX
1,000 deathsSevere damage ($5–24M)tsunami
- 1757M7.0
Cotopaxi,Tungurahua, Latacunga
22 Feb 1757 · 44 km away · intensity IX
1,000 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.