Reviewed by USGSEcuador69y ago
M6.9 earthquake 51 km NW of Valdez, Ecuador
Saturday, February 1, 1958, 16:10:16 UTC · 1.541°N, 79.338°W
A magnitude 6.9 earthquake struck 51 km NW of Valdez, Ecuador on Saturday, February 1, 1958, 16:10:16 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M7.6 on January 19, 1958.
- Magnitude
- 6.9
- Strong · mw
- Depth
- 15 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 earthquakeDashed circle: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
338 kilotons of TNT
That is about 22 times the Hiroshima bomb. It released about 708 times the energy of a magnitude 5.0.
Tectonic setting
77 km
from the nearest mapped plate boundary, between the Nazca and North Andes 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 lists 2 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M6.3 on February 1, 1958. 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 32 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 · 65 km S of this epicenter
- 7.812 km SE of Pedernales, EcuadorMay 14, 1942 · 187 km SW of this epicenter
- 7.6near the coast of EcuadorJanuary 19, 1958 · 61 km S of this epicenter
- 7.07 km NNE of Tosagua, EcuadorJanuary 16, 1956 · 270 km S of this epicenter
- 6.824 km NNE of Esmeraldas, EcuadorJanuary 19, 1958 · 49 km SW of this epicenter
- 6.813 km N of Muisne, EcuadorJune 30, 1916 · 117 km SW of this epicenter
- 6.667 km NNW of Esmeraldas, EcuadorJune 1, 1907 · 68 km W of this epicenter
- 6.645 km ESE of Esmeraldas, EcuadorOctober 23, 1944 · 86 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 24 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 72,675 recorded deaths. The most severe:
- 1868M7.7
Guayaquil,Ibarra; Colombia: San Pablo
16 Aug 1868 · 188 km away · intensity X
70,000 deathsExtreme damage ($25M+)
- 1906M8.8
Off Coast
31 Jan 1906 · 65 km away · intensity IX
1,000 deathsSevere damage ($5–24M)tsunami
- 1757M7.0
Cotopaxi,Tungurahua, Latacunga
22 Feb 1757 · 284 km away · intensity IX
1,000 deathsSevere damage ($5–24M)
- 1923M6.2
Ipiales
14 Dec 1923 · 189 km away · intensity IX
300 deathsModerate damage ($1–5M)
- 1936M5.6
Colombia
9 Jan 1936 · 199 km away · intensity VII
250 deathsModerate damage ($1–5M)
- 1958M7.6
Colombia-Ecuador
19 Jan 1958 · 19 km away · intensity IX
115 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.