M4.2 earthquake 33 km S of Puerto El Triunfo, El Salvador

Sunday, March 18, 2001, 12:08:03 UTC · 12.984°N, 88.540°W

A magnitude 4.2 earthquake struck 33 km S of Puerto El Triunfo, El Salvador on Sunday, March 18, 2001, 12:08:03 UTC, at a depth of 33.0 km (shallow).

Magnitude: 4.2; 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

30 tons of TNT

That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.

Tectonic setting

116 km

from the nearest mapped plate boundary, between the Caribbean and Cocos plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

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 10 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.8 on March 29, 2001. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 458 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 69 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 46,107 recorded deaths. The most severe:

1976M7.5
Chimaltenango, Guatemala City
4 Feb 1976 · 267 km away · intensity IX
23,000 deaths$2.1 billion damagetsunami
1972M6.2
Managua
23 Dec 1972 · 273 km away
10,000 deaths$3.0 billion damage
1917M6.0
Guatemala City
26 Dec 1917 · 286 km away · intensity IX
2,650 deathsExtreme damage ($25M+)
1902M7.5
Quezaltenango, San Marcos
19 Apr 1902 · 289 km away
2,000 deathsSevere damage ($5–24M)tsunami
1986M5.4
San Salvador
10 Oct 1986 · 113 km away
1,100 deaths$1.5 billion damage
1951M6.5
Jucuapa
6 May 1951 · 80 km away
1,100 deaths$23 million damage

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers