Magnitude6.3

Reviewed by USGSMexico36y ago

M6.3 earthquake 172 km SSW of Emiliano Zapata, Mexico

Tuesday, January 1, 1991, 00:06:31 UTC · 18.068°N, 105.847°W

A magnitude 6.3 earthquake struck 172 km SSW of Emiliano Zapata, Mexico on Tuesday, January 1, 1991, 00:06:31 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M6.5 on August 29, 1989.

Magnitude
6.3
Strong · mw
Depth
35 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: 100 km aftershock search area

In context

How big was it, and why here?

Energy released

43 kilotons of TNT

That is about 3 times the Hiroshima bomb. It released about 89 times the energy of a magnitude 5.0.

Tectonic setting

19 km

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

Depth: shallow

35 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 M5.8 on January 1, 1991. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M4M5M61h6h1d3d7d14d30dMainshock M6.3
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 5.8184 km SSW of Emiliano Zapata, Mexico36y ago · 13 km S of this epicenter
  2. 5.0143 km SW of Emiliano Zapata, Mexico36y ago · 33 km N of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 127 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 18 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 4,475 recorded deaths. The most severe:

  1. 1806M7.5

    Jalisco,Oaxaca,Michoacan

    25 Mar 1806 · 235 km away · intensity VIII

    2,000 deathsExtreme damage ($25M+)

  2. 1818M8.2

    Morelos-Guerrero,Mexico City,Guadalajara

    31 May 1818 · 231 km away · intensity X

    2,000 deathsSevere damage ($5–24M)tsunami

  3. 1932M8.1

    Near Coast Of Jalisco

    3 Jun 1932 · 267 km away · intensity X

    400 deathsSevere damage ($5–24M)tsunami

  4. 1932M7.7

    Central

    22 Jun 1932 · 202 km away

    75 deathsSevere damage ($5–24M)tsunami

  5. 1900M7.3

    Mexico

    20 Jan 1900 · 233 km away · intensity VIII

    Severe damage ($5–24M)tsunami

  6. 1934M7.0

    Jalisco

    30 Nov 1934 · 60 km away

    Severe damage ($5–24M)tsunami

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

Nearby trackers

Closest city pages