Reviewed by USGSMexico48y ago
M4.7 earthquake 113 km SSW of Ixtapa, Mexico
Friday, April 6, 1979, 20:22:19 UTC · 16.757°N, 102.123°W
A magnitude 4.7 earthquake struck 113 km SSW of Ixtapa, Mexico on Friday, April 6, 1979, 20:22:19 UTC, at a depth of 51.0 km (shallow). It is the strongest earthquake within 300 km since an M5.1 on March 22, 1979.
- Magnitude
- 4.7
- Light · mb
- Depth
- 51 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 earthquake
In context
How big was it, and why here?
Energy released
169 tons of TNT
That is about 1/89 of the Hiroshima bomb. A magnitude 5.0 releases about 3 times more energy.
Tectonic setting
44 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
51 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 100 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.87 km E of Los Tepames, MexicoJune 18, 1932 · 300 km NW of this epicenter
- 7.621 km ESE of Coalcomán de Vázquez Pallares, MexicoApril 15, 1941 · 233 km NW of this epicenter
- 7.619 km W of Arteaga, MexicoJune 7, 1911 · 182 km N of this epicenter
- 7.612 km SSE of Vallecitos de Zaragoza, MexicoMarch 14, 1979 · 148 km NE of this epicenter
- 7.525 km S of Tetitlán, MexicoDecember 16, 1911 · 156 km E of this epicenter
- 7.527 km SSE of San Andrés Playa Encantada (El Podrido), MexicoJuly 30, 1909 · 278 km E of this epicenter
- 7.535 km SW of Aguililla, MexicoJanuary 30, 1973 · 213 km NW of this epicenter
- 7.418 km SSW of Palos Blancos, MexicoFebruary 22, 1943 · 107 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 33 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,267 recorded deaths. The most severe:
- 1806M7.5
Jalisco,Oaxaca,Michoacan
25 Mar 1806 · 297 km away · intensity VIII
2,000 deathsExtreme damage ($25M+)
- 1941M7.6
Michoacan, Colima, Jalisco
15 Apr 1941 · 233 km away · intensity VII
84 deaths$2 million damagetsunami
- 1964M7.3
Guerrero
6 Jul 1964 · 222 km away
78 deathsSevere damage ($5–24M)
- 1973M7.5
S, Farias, Tecoman
30 Jan 1973 · 213 km away
56 deathsModerate damage ($1–5M)tsunami
- 1864M7.0
Puebla,Veracruz,Acultzingo,Acatzingo
3 Oct 1864 · 230 km away
20 deathsSevere damage ($5–24M)
- 1907M8.3
Guerrero
15 Apr 1907 · 228 km away
8 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.