Reviewed by USGSNicaragua107y ago
M7.2 earthquake 7 km SW of El Viejo, Nicaragua
Monday, March 28, 1921, 07:49:28 UTC · 12.610°N, 87.216°W
A magnitude 7.2 earthquake struck 7 km SW of El Viejo, Nicaragua on Monday, March 28, 1921, 07:49:28 UTC, at a depth of 65.0 km (shallow). It is the strongest earthquake within 300 km since an M7.7 on September 7, 1915.
- Magnitude
- 7.2
- Major · mw
- Depth
- 65 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 earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
951 kilotons of TNT
That is about 63 times the Hiroshima bomb. It released about 1,995 times the energy of a magnitude 5.0.
Tectonic setting
151 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
65 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 has not published any M2.5+ earthquake within 200 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 11 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.712 km NW of Chalatenango, El SalvadorSeptember 7, 1915 · 257 km NW of this epicenter
- 7.392 km SW of San Juan del Sur, NicaraguaDecember 30, 1907 · 229 km S of this epicenter
- 7.2116 km SW of Corinto, NicaraguaJuly 1, 1907 · 126 km SW of this epicenter
- 6.78 km S of San Juan Opico, El SalvadorJune 8, 1917 · 267 km NW of this epicenter
- 6.7100 km SSW of Intipucá, El SalvadorJune 29, 1919 · 122 km W of this epicenter
- 6.4177 km SSW of Puerto El Triunfo, El SalvadorJanuary 15, 1913 · 237 km W of this epicenter
- 6.4144 km SW of Masachapa, NicaraguaJuly 31, 1918 · 195 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 26 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,342 recorded deaths. The most severe:
- 1854
San Salvador
14 Apr 1854 · 252 km away
1,000 deathsExtreme damage ($25M+)
- 1873
Santa Tomas, San Vicente
4 Mar 1873 · 237 km away
800 deathsExtreme damage ($25M+)
- 1873
Salvador,San Vicente
11 Apr 1873 · 222 km away
300 deaths
- 1902M7.0
El Salvador-Guatemala
26 Feb 1902 · 266 km away
185 deathsSevere damage ($5–24M)tsunami
- 1765
Chiquimula
20 Apr 1765 · 247 km away
50 deathsModerate damage ($1–5M)
- 1915M7.7
El Salvador
7 Sep 1915 · 257 km away · intensity VIII
7 deathsModerate damage ($1–5M)tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.