Reviewed by USGSPeru35y ago
M4.8 earthquake 26 km NNW of Moyobamba, Peru
Tuesday, May 28, 1991, 03:22:23 UTC · 5.808°S, 77.057°W
A magnitude 4.8 earthquake struck 26 km NNW of Moyobamba, Peru on Tuesday, May 28, 1991, 03:22:23 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M4.9 on May 18, 1991.
- Magnitude
- 4.8
- 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 earthquake
In context
How big was it, and why here?
Energy released
239 tons of TNT
That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.
Tectonic setting
177 km
from the nearest mapped plate boundary, between the Sunda and Australian 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 130 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.516 km W of Barranca, PeruSeptember 28, 1906 · 114 km N of this epicenter
- 7.323 km N of Bellavista, PeruMay 14, 1928 · 182 km W of this epicenter
- 7.111 km NE of Rioja, PeruApril 5, 1991 · 20 km S of this epicenter
- 7.115 km SSW of Huabal, PeruJuly 18, 1928 · 213 km W of this epicenter
- 7.092 km NNE of La Peca, PeruApril 12, 1983 · 158 km NW of this epicenter
- 6.86 km SSW of Quiches, PeruNovember 10, 1946 · 298 km S of this epicenter
- 6.8109 km W of Alianza Cristiana, PeruNovember 23, 1986 · 277 km N of this epicenter
- 6.848 km NNE of Segunda Jerusalén - Azunguillo, PeruJune 19, 1968 · 27 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 11 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 323 recorded deaths. The most severe:
- 1990M6.5
Moyabamba-Riojo
30 May 1990 · 30 km away · intensity VI
200 deaths$1 million damage
- 1991M6.7
Rioja, Moyobamba, Nueva Cajamarca
5 Apr 1991 · 20 km away · intensity VII
53 deathsSevere damage ($5–24M)
- 1928M7.3
Chacahpoyas,Huancabamba,Cajamarca,Pinpincos
14 May 1928 · 183 km away · intensity X
29 deathsSevere damage ($5–24M)
- 1968M6.8
San Martin,Moyobamba,Yantalo,Rioja,Lamas
19 Jun 1968 · 22 km away
15 deathsUnder $1 million damage
- 1972M6.1
Juanjui
20 Mar 1972 · 114 km away · intensity IX
12 deaths$20 million damage
- 1983M6.5
Chimbote
12 Apr 1983 · 158 km away
10 deathsUnder $1 million damage
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.