Reviewed by USGSMexico13y ago
M4.0 earthquake 9 km E of La Libertad, Mexico
Friday, September 20, 2013, 00:43:27 UTC · 14.583°N, 92.109°W
A magnitude 4.0 earthquake struck 9 km E of La Libertad, Mexico on Friday, September 20, 2013, 00:43:27 UTC, at a depth of 81.0 km (intermediate).
- Magnitude
- 4.0
- Light · md
- Depth
- 81 km
- Intermediate
- 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
15 tons of TNT
That is about 1/998 of the Hiroshima bomb. A magnitude 5.0 releases about 32 times more energy.
Tectonic setting
130 km
from the nearest mapped plate boundary, between the Cocos and North American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
81 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.5 on September 30, 2013. 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 664 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.726 km SSW of La Gomera, GuatemalaAugust 6, 1942 · 130 km SE of this epicenter
- 7.433 km S of Champerico, GuatemalaNovember 7, 2012 · 70 km S of this epicenter
- 7.34 km SSW of Puerto Madero, MexicoDecember 14, 1935 · 37 km W of this epicenter
- 7.334 km SW of Puerto Madero, MexicoApril 29, 1970 · 56 km W of this epicenter
- 7.2127 km SW of La Esperanza (El Zapotal), MexicoMarch 30, 1914 · 201 km W of this epicenter
- 7.213 km NW of Ocozocoautla de Espinosa, MexicoOctober 21, 1995 · 290 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 38 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 5,799 recorded deaths. The most severe:
- 1917M6.0
Guatemala City
26 Dec 1917 · 162 km away · intensity IX
2,650 deathsExtreme damage ($25M+)
- 1902M7.5
Quezaltenango, San Marcos
19 Apr 1902 · 136 km away
2,000 deathsSevere damage ($5–24M)tsunami
- 1773
St. Jago
3 Jun 1773 · 152 km away
600 deathsExtreme damage ($25M+)tsunami
- 1874M7.1
Antigua,Chimaltenango,Amatitlan
3 Sep 1874 · 152 km away · intensity VIII
300 deathsSevere damage ($5–24M)
- 1773M7.5
Antigua
29 Jul 1773 · 152 km away · intensity VIII
100 deathsModerate damage ($1–5M)
- 2012M7.3
San Marcos, San Cristobal Cochu
7 Nov 2012 · 70 km away
48 deaths$210 million damagetsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.