M5.1 earthquake 65 km NE of Yambrasbamba, Peru

Friday, June 21, 1968, 07:24:18 UTC · 5.390°S, 77.441°W

A magnitude 5.1 earthquake struck 65 km NE of Yambrasbamba, Peru on Friday, June 21, 1968, 07:24:18 UTC, at a depth of 20.0 km (shallow). It is the strongest earthquake within 300 km since an M5.7 on June 21, 1968.

Magnitude: 5.1; Moderate · mw
Depth: 20 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: 75 km aftershock search area

In context

How big was it, and why here?

Energy released

773 tons of TNT

That is about 1/19 of the Hiroshima bomb. It released about 2 times the energy of a magnitude 5.0.

Tectonic setting

223 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

20 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 75 km

USGS lists 7 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.5 on July 7, 1968. 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 33 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 4 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 44 recorded deaths. The most severe:

1928M7.3
Chacahpoyas,Huancabamba,Cajamarca,Pinpincos
14 May 1928 · 136 km away · intensity X
29 deathsSevere damage ($5–24M)
1968M6.8
San Martin,Moyobamba,Yantalo,Rioja,Lamas
19 Jun 1968 · 46 km away
15 deathsUnder $1 million damage
1928M7.0
Peru
18 Jul 1928 · 173 km away · intensity VI
tsunami
1907
Peru
16 Nov 1907 · 300 km away · intensity VI

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

Nearby trackers