Magnitude7.8

Reviewed by USGSEcuador85y ago

M7.8 earthquake 12 km SE of Pedernales, Ecuador

Thursday, May 14, 1942, 02:13:27 UTC · 0.014°S, 79.982°W

A magnitude 7.8 earthquake struck 12 km SE of Pedernales, Ecuador on Thursday, May 14, 1942, 02:13:27 UTC, at a depth of 20.0 km (shallow). It is the strongest earthquake within 300 km since an M8.8 on January 31, 1906.

Magnitude
7.8
Major · mw
Depth
20 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 earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

7.6 megatons of TNT

That is about 502 times the Hiroshima bomb. It released about 15,849 times the energy of a magnitude 5.0.

Tectonic setting

112 km

from the nearest mapped plate boundary, between the Nazca and North Andes 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 200 km

USGS lists 2 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.4 on May 17, 1942. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M7M81h6h1d3d7d14d30dMainshock M7.8
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 6.427 km WSW of Muisne, Ecuador85y ago · 68 km NW of this epicenter
  2. 6.36 km SSW of Muisne, Ecuador85y ago · 64 km N of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 15 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 21 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 112,790 recorded deaths. The most severe:

  1. 1868M7.7

    Guayaquil,Ibarra; Colombia: San Pablo

    16 Aug 1868 · 204 km away · intensity X

    70,000 deathsExtreme damage ($25M+)

  2. 1797M8.3

    Riobamba, Quito, Cuzco; Peru; Colombia

    4 Feb 1797 · 232 km away · intensity XI

    40,000 deathsExtreme damage ($25M+)tsunami

  3. 1906M8.8

    Off Coast

    31 Jan 1906 · 127 km away · intensity IX

    1,000 deathsSevere damage ($5–24M)tsunami

  4. 1757M7.0

    Cotopaxi,Tungurahua, Latacunga

    22 Feb 1757 · 183 km away · intensity IX

    1,000 deathsSevere damage ($5–24M)

  5. 1923M6.2

    Ipiales

    14 Dec 1923 · 264 km away · intensity IX

    300 deathsModerate damage ($1–5M)

  6. 1936M5.6

    Colombia

    9 Jan 1936 · 292 km away · intensity VII

    250 deathsModerate damage ($1–5M)

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers

Closest city pages