Reviewed by USGSMexico48y ago
M4.4 earthquake 7 km W of Santa María Tonameca, Mexico
Monday, December 11, 1978, 15:28:45 UTC · 15.748°N, 96.620°W
A magnitude 4.4 earthquake struck 7 km W of Santa María Tonameca, Mexico on Monday, December 11, 1978, 15:28:45 UTC, at a depth of 33.0 km (shallow).
- Magnitude
- 4.4
- Light · mb
- Depth
- 33 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
43 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
33 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 6 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.4 on December 28, 1978. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 5.14 km W of Candelaria Loxicha, Mexico48y ago · 22 km NE of this epicenter
- 5.45 km S of San Miguel Suchixtepec, Mexico48y ago · 37 km NE of this epicenter
- 4.54 km WNW of Los Naranjos Esquipulas, Mexico48y ago · 30 km NE of this epicenter
- 4.93 km SE of San Francisco Loxicha, Mexico48y ago · 16 km N of this epicenter
- 4.67 km WNW of Los Naranjos Esquipulas, Mexico48y ago · 31 km N of this epicenter
- 4.74 km W of Candelaria Loxicha, Mexico48y ago · 22 km NE of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 141 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.015 km ESE of San Gabriel Mixtepec, MexicoJune 17, 1928 · 49 km NW of this epicenter
- 7.82 km NW of Teojomulco, MexicoApril 15, 1907 · 116 km NW of this epicenter
- 7.72 km ESE of San Agustín Loxicha, MexicoNovember 29, 1978 · 29 km N of this epicenter
- 7.65 km SSW of San Miguel Suchixtepec, MexicoJanuary 15, 1931 · 36 km NE of this epicenter
- 7.56 km WSW of San Miguel Panixtlahuaca, MexicoOctober 9, 1928 · 102 km NW of this epicenter
- 7.56 km S of Copala, MexicoMarch 26, 1908 · 268 km W of this epicenter
- 7.48 km ENE of Santiago Xanica, MexicoMarch 22, 1928 · 59 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 47 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 687 recorded deaths. The most severe:
- 1973M6.2
Veracruz, Mexico City
28 Aug 1973 · 280 km away · intensity VII
527 deathsSevere damage ($5–24M)
- 1957M7.9
Acapulco,Mexico City
28 Jul 1957 · 278 km away · intensity VII
65 deaths$25 million damagetsunami
- 1870M7.9
Oaxaca,Zanaguia,San Francisco Ozolotepec
11 May 1870 · 52 km away
24 deathsSevere damage ($5–24M)tsunami
- 1968M7.3
Oaxaca, Guerrero
2 Aug 1968 · 147 km away · intensity VII
18 deaths$2 million damagetsunami
- 1787M8.6
San Marcos, Oaxaca
28 Mar 1787 · 218 km away · intensity IX
11 deathsSevere damage ($5–24M)tsunami
- 1978M7.7
Oaxaca
29 Nov 1978 · 29 km away
9 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.