M7.2 earthquake 7 km NNE of Cașoca, Romania

Saturday, August 30, 1986, 21:28:35 UTC · 45.547°N, 26.316°E

A magnitude 7.2 earthquake struck 7 km NNE of Cașoca, Romania on Saturday, August 30, 1986, 21:28:35 UTC, at a depth of 132.3 km (intermediate). It is the strongest earthquake within 300 km since an M7.5 on March 4, 1977.

Magnitude: 7.2; Major · mw
Depth: 132 km; Intermediate
Felt reports: 0; Did You Feel It?
Est. shaking: VI; Strong (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured 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

531 km

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

Depth: intermediate

132 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 200 km

USGS lists 7 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M4.1 on September 2, 1986. 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 24 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 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 2,692 recorded deaths. The most severe:

1977M7.5
Bucharest
4 Mar 1977 · 39 km away
1,641 deaths$2.0 billion damage
1940M7.3
Romania
10 Nov 1940 · 47 km away · intensity X
1,000 deaths$10 million damage
1838M6.9
Carpathian Fold,Vrancea
23 Jan 1838 · 28 km away · intensity VIII
42 deathsModerate damage ($1–5M)tsunami
1901M7.2
Balchik
31 Mar 1901 · 295 km away · intensity X
4 deathsSevere damage ($5–24M)tsunami
1986M5.6
Veliko Turnovo-Turgovishte
7 Dec 1986 · 255 km away · intensity VII
3 deaths$5 million damage
1986M6.9
Bucharest, Kishinev-Kagul
30 Aug 1986 · 0 km away · intensity VIII
2 deaths$730 million damage

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

Nearby trackers