Magnitude4.4

Reviewed by USGSMexico48y ago

M4.4 earthquake 27 km NE of Petatlán, Mexico

Wednesday, March 14, 1979, 22:05:08 UTC · 17.707°N, 101.081°W

A magnitude 4.4 earthquake struck 27 km NE of Petatlán, Mexico on Wednesday, March 14, 1979, 22:05:08 UTC, at a depth of 61.0 km (shallow).

Magnitude
4.4
Light · mb
Depth
61 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 earthquakeDashed circle: 50 km aftershock search area

In context

How big was it, and why here?

Energy released

60 tons of TNT

That is about 1/251 of the Hiroshima bomb. A magnitude 5.0 releases about 8 times more energy.

Tectonic setting

96 km

from the nearest mapped plate boundary, between the Cocos and North American plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: shallow

61 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 lists 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.4 on March 18, 1979. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M51h6h1d3d7d14d30dMainshock M4.4
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.92 km WSW of Petatlán, Mexico48y ago · 30 km SW of this epicenter
  2. 5.419 km NNE of Coyuquilla Norte, Mexico48y ago · 20 km SE of this epicenter
  3. 4.420 km ENE of Vallecitos de Zaragoza, Mexico48y ago · 33 km N of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 121 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 50 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 534 recorded deaths. The most severe:

  1. 1912M6.7

    Central, Acambay, Tixmadeje

    19 Nov 1912 · 242 km away

    202 deathsSevere damage ($5–24M)

  2. 1941M7.6

    Michoacan, Colima, Jalisco

    15 Apr 1941 · 229 km away · intensity VII

    84 deaths$2 million damagetsunami

  3. 1964M7.3

    Guerrero

    6 Jul 1964 · 69 km away

    78 deathsSevere damage ($5–24M)

  4. 1957M7.9

    Acapulco,Mexico City

    28 Jul 1957 · 250 km away · intensity VII

    65 deaths$25 million damagetsunami

  5. 1973M7.5

    S, Farias, Tecoman

    30 Jan 1973 · 220 km away

    56 deathsModerate damage ($1–5M)tsunami

  6. 1864M7.0

    Puebla,Veracruz,Acultzingo,Acatzingo

    3 Oct 1864 · 106 km away

    20 deathsSevere damage ($5–24M)

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

Nearby trackers

Closest city pages