Magnitude5.5

Reviewed by USGSMexico61y ago

M5.5 earthquake 1 km NNE of Puerto Ángel, Mexico

Tuesday, August 24, 1965, 00:56:24 UTC · 15.680°N, 96.484°W

A magnitude 5.5 earthquake struck 1 km NNE of Puerto Ángel, Mexico on Tuesday, August 24, 1965, 00:56:24 UTC, at a depth of 27.6 km (shallow). It is the strongest earthquake within 300 km since an M7.4 on August 23, 1965.

Magnitude
5.5
Moderate · mw
Depth
28 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: 75 km aftershock search area

In context

How big was it, and why here?

Energy released

3 kilotons of TNT

That is about 1/5 of the Hiroshima bomb. It released about 6 times the energy of a magnitude 5.0.

Tectonic setting

35 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

28 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 75 km

USGS lists 1 M2.5+ earthquake within 75 km in the following 30 days; the largest was M5.8 on August 24, 1965. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M61h6h1d3d7d14d30dMainshock M5.5
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.88 km E of Cuapinolito (Azulillo), Mexico61y ago · 31 km NE of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 84 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 40 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 133 recorded deaths. The most severe:

  1. 1957M7.9

    Acapulco,Mexico City

    28 Jul 1957 · 294 km away · intensity VII

    65 deaths$25 million damagetsunami

  2. 1870M7.9

    Oaxaca,Zanaguia,San Francisco Ozolotepec

    11 May 1870 · 37 km away

    24 deathsSevere damage ($5–24M)tsunami

  3. 1787M8.6

    San Marcos, Oaxaca

    28 Mar 1787 · 234 km away · intensity IX

    11 deathsSevere damage ($5–24M)tsunami

  4. 1882M7.5

    Puebla,Huahuapan,Huamuxtitlan,Xalpatlahuac

    19 Jul 1882 · 290 km away

    7 deathsSevere damage ($5–24M)

  5. 1801M7.0

    Oaxaca

    5 Oct 1801 · 71 km away

    7 deathsSevere damage ($5–24M)

  6. 1965M7.8

    Mexico City, Oaxaca

    23 Aug 1965 · 100 km away

    6 deathsLimited damage (under $1M)tsunami

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

Nearby trackers

Closest city pages