Magnitude6.6

Reviewed by USGSMexico78y ago

M6.6 earthquake 142 km WNW of Corral del Risco (Punta de Mita), Mexico

Saturday, December 4, 1948, 00:22:48 UTC · 21.182°N, 106.818°W

A magnitude 6.6 earthquake struck 142 km WNW of Corral del Risco (Punta de Mita), Mexico on Saturday, December 4, 1948, 00:22:48 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.8 on January 2, 1931.

Magnitude
6.6
Strong · mw
Depth
15 km
Shallow
Felt reports
0
Did You Feel It?
Est. shaking
V
Moderate (ShakeMap)
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

116 kilotons of TNT

That is about 8 times the Hiroshima bomb. It released about 243 times the energy of a magnitude 5.0.

Tectonic setting

25 km

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

Depth: shallow

15 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 has not published any M2.5+ earthquake within 100 km in the 30 days after this event.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 29 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 6 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 4 recorded deaths. The most severe:

  1. 1948M6.6

    Maria Madre Island

    4 Dec 1948 · 0 km away

    4 deathsSevere damage ($5–24M)tsunami

  2. 1900M7.3

    Mexico

    20 Jan 1900 · 230 km away · intensity VIII

    Severe damage ($5–24M)tsunami

  3. 1925M7.0

    S. Mexico

    16 Nov 1925 · 299 km away

    Moderate damage ($1–5M)tsunami

  4. 1900M6.9

    Near Coast Of Jalisco

    16 May 1900 · 230 km away

    Limited damage (under $1M)tsunami

  5. 1837M7.5

    Guadalajara

    22 Nov 1837 · 230 km away

  6. 1875M6.5

    S. Mexico

    24 Feb 1875 · 230 km away · intensity VI

    tsunami

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

Nearby trackers

Closest city pages