Reviewed by USGSMexico54y ago
M7.5 earthquake 35 km SW of Aguililla, Mexico
Tuesday, January 30, 1973, 21:01:12 UTC · 18.481°N, 102.996°W
A magnitude 7.5 earthquake struck 35 km SW of Aguililla, Mexico on Tuesday, January 30, 1973, 21:01:12 UTC, at a depth of 43.0 km (shallow). It is the strongest earthquake within 300 km since an M7.6 on April 15, 1941.
- Magnitude
- 7.5
- Major · ms
- Depth
- 43 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VIII
- Severe (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
2.7 megatons of TNT
That is about 178 times the Hiroshima bomb. It released about 5,623 times the energy of a magnitude 5.0.
Tectonic setting
94 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
43 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 3 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M5.6 on February 10, 1973. 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 67 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.11932 Jalisco, Mexico EarthquakeJune 3, 1932 · 176 km NW of this epicenter
- 7.87 km E of Los Tepames, MexicoJune 18, 1932 · 89 km NW of this epicenter
- 7.712 km NNE of La Central, MexicoJune 22, 1932 · 169 km NW of this epicenter
- 7.621 km ESE of Coalcomán de Vázquez Pallares, MexicoApril 15, 1941 · 22 km N of this epicenter
- 7.619 km W of Arteaga, MexicoJune 7, 1911 · 57 km E of this epicenter
- 7.418 km SSW of Palos Blancos, MexicoFebruary 22, 1943 · 210 km SE of this epicenter
- 7.310 km SW of Villa Nicolás Bravo, MexicoJuly 6, 1964 · 255 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 36 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 4,781 recorded deaths. The most severe:
- 1806M7.5
Jalisco,Oaxaca,Michoacan
25 Mar 1806 · 97 km away · intensity VIII
2,000 deathsExtreme damage ($25M+)
- 1818M8.2
Morelos-Guerrero,Mexico City,Guadalajara
31 May 1818 · 121 km away · intensity X
2,000 deathsSevere damage ($5–24M)tsunami
- 1932M8.1
Near Coast Of Jalisco
3 Jun 1932 · 160 km away · intensity X
400 deathsSevere damage ($5–24M)tsunami
- 1941M7.6
Michoacan, Colima, Jalisco
15 Apr 1941 · 22 km away · intensity VII
84 deaths$2 million damagetsunami
- 1964M7.3
Guerrero
6 Jul 1964 · 255 km away
78 deathsSevere damage ($5–24M)
- 1932M7.7
Central
22 Jun 1932 · 169 km away
75 deathsSevere damage ($5–24M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.