M2.7 earthquake in Croatia

Sunday, January 3, 2021, 08:19:57 UTC · 45.721°N, 16.169°E

A magnitude 2.7 earthquake struck in Croatia on Sunday, January 3, 2021, 08:19:57 UTC, at a depth of 10.0 km (shallow). USGS received 3 “Did You Feel It?” reports, with a maximum reported intensity of III (weak).

Magnitude: 2.7; Minor · ml
Depth: 10 km; Shallow
Felt reports: 3; Max intensity III
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

169 kg of TNT

That is about 1/88,990 of the Hiroshima bomb. A magnitude 5.0 releases about 2,818 times more energy.

Tectonic setting

738 km

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

Depth: shallow

10 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

Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.

Place	Intensity	Reports	Distance
Zagreb, Grad Zagreb, Croatia	III · Weak	2	20 km
Čazma, Bjelovar-Bilogora, Croatia	III · Weak	1	36 km

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 7 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.7 on January 6, 2021. 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 111 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 51 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 1,222 recorded deaths. The most severe:

1976M6.5
Ne, Balkans Nw: Slovenia: Nw
6 May 1976 · 234 km away · intensity X
978 deaths$3.6 billion damage
1763M6.2
Gyor; Czechoslovakia: Komarom
28 Jun 1763 · 269 km away · intensity IX
83 deathsLimited damage (under $1M)
1873
Bellunese
29 Jun 1873 · 296 km away · intensity X
55 deathsModerate damage ($1–5M)
1943
Bosnia-Herzegovina
29 Jan 1943 · 171 km away
19 deathsLimited damage (under $1M)
1930M6.0
Senigallia
30 Oct 1930 · 294 km away · intensity IX
18 deathsSevere damage ($5–24M)tsunami
1969M6.0
Bosnia-Herzegovina: Banja Luka
26 Oct 1969 · 127 km away · intensity VIII
14 deaths$50 million damage

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

Nearby trackers