Magnitude7.4

Reviewed by USGSMexico90y ago

M7.4 earthquake 3 km W of Huixtepec, Mexico

Thursday, December 23, 1937, 13:18:03 UTC · 16.656°N, 98.338°W

A magnitude 7.4 earthquake struck 3 km W of Huixtepec, Mexico on Thursday, December 23, 1937, 13:18:03 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M7.6 on January 15, 1931.

Magnitude
7.4
Major · mw
Depth
25 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

1.9 megatons of TNT

That is about 126 times the Hiroshima bomb. It released about 3,981 times the energy of a magnitude 5.0.

Tectonic setting

101 km

from the nearest mapped plate boundary, between the Cocos and North American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: shallow

25 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 3 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.5 on January 2, 1938. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M6M71h6h1d3d7d14d30dMainshock M7.4
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 6.514 km S of Santiago Tepextla, Mexico90y ago · 52 km S of this epicenter
  2. 5.854 km SSW of Corralero, Mexico90y ago · 99 km S of this epicenter
  3. 6.17 km WNW of El Carrizo, Mexico90y ago · 50 km SE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 43 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 64 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 92 recorded deaths. The most severe:

  1. 1870M7.9

    Oaxaca,Zanaguia,San Francisco Ozolotepec

    11 May 1870 · 259 km away

    24 deathsSevere damage ($5–24M)tsunami

  2. 1864M7.0

    Puebla,Veracruz,Acultzingo,Acatzingo

    3 Oct 1864 · 209 km away

    20 deathsSevere damage ($5–24M)

  3. 1787M8.6

    San Marcos, Oaxaca

    28 Mar 1787 · 24 km away · intensity IX

    11 deathsSevere damage ($5–24M)tsunami

  4. 1907M8.3

    Guerrero

    15 Apr 1907 · 181 km away

    8 deathsModerate damage ($1–5M)tsunami

  5. 1882M7.5

    Puebla,Huahuapan,Huamuxtitlan,Xalpatlahuac

    19 Jul 1882 · 117 km away

    7 deathsSevere damage ($5–24M)

  6. 1801M7.0

    Oaxaca

    5 Oct 1801 · 244 km away

    7 deathsSevere damage ($5–24M)

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

Nearby trackers

Closest city pages