Reviewed by USGSMexico99y ago
M7.5 earthquake 6 km WSW of San Miguel Panixtlahuaca, Mexico
Tuesday, October 9, 1928, 03:01:14 UTC · 16.233°N, 97.434°W
A magnitude 7.5 earthquake struck 6 km WSW of San Miguel Panixtlahuaca, Mexico on Tuesday, October 9, 1928, 03:01:14 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M8.0 on June 17, 1928.
- Magnitude
- 7.5
- Major · mw
- Depth
- 25 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
2.8 megatons of TNT
That is about 184 times the Hiroshima bomb. It released about 5,821 times the energy of a magnitude 5.0.
Tectonic setting
84 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
25 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 200 km
USGS lists 1 M2.5+ earthquake within 200 km in the following 30 days; the largest was M6.0 on October 30, 1928. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 28 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 · 56 km E of this epicenter
- 7.82 km NW of Teojomulco, MexicoApril 15, 1907 · 46 km NE of this epicenter
- 7.527 km SSE of San Andrés Playa Encantada (El Podrido), MexicoJuly 30, 1909 · 225 km W of this epicenter
- 7.56 km S of Copala, MexicoMarch 26, 1908 · 169 km W of this epicenter
- 7.48 km ENE of Santiago Xanica, MexicoMarch 22, 1928 · 138 km E of this epicenter
- 7.440 km S of Corralero, MexicoAugust 4, 1928 · 94 km SW of this epicenter
- 7.215 km SSW of Colonia Luces en el Mar, MexicoMarch 27, 1908 · 286 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 50 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 68 recorded deaths. The most severe:
- 1870M7.9
Oaxaca,Zanaguia,San Francisco Ozolotepec
11 May 1870 · 153 km away
24 deathsSevere damage ($5–24M)tsunami
- 1787M8.6
San Marcos, Oaxaca
28 Mar 1787 · 118 km away · intensity IX
11 deathsSevere damage ($5–24M)tsunami
- 1907M8.3
Guerrero
15 Apr 1907 · 286 km away
8 deathsModerate damage ($1–5M)tsunami
- 1882M7.5
Puebla,Huahuapan,Huamuxtitlan,Xalpatlahuac
19 Jul 1882 · 182 km away
7 deathsSevere damage ($5–24M)
- 1801M7.0
Oaxaca
5 Oct 1801 · 142 km away
7 deathsSevere damage ($5–24M)
- 1854M7.7
Veracruz,Oaxaca
5 May 1854 · 31 km away · intensity IX
4 deathsSevere damage ($5–24M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.