Reviewed by USGSCroatia5y ago
M6.4 earthquake 2 km WSW of Petrinja, Croatia
Tuesday, December 29, 2020, 11:19:54 UTC · 45.424°N, 16.257°E
A magnitude 6.4 earthquake struck 2 km WSW of Petrinja, Croatia on Tuesday, December 29, 2020, 11:19:54 UTC, at a depth of 10.0 km (shallow). USGS received 1,782 “Did You Feel It?” reports, with a maximum reported intensity of IX (violent). The USGS PAGER alert is orange: significant casualties and damage are likely. It is the strongest earthquake within 300 km since an M6.5 on May 6, 1976.
- Magnitude
- 6.4
- Strong · mww
- Depth
- 10 km
- Shallow
- Felt reports
- 1,782
- Max intensity IX
- Est. shaking
- IX
- Violent (ShakeMap)
- PAGER alert
- Orange
- Impact estimate
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
60 kilotons of TNT
That is about 4 times the Hiroshima bomb. It released about 126 times the energy of a magnitude 5.0.
Tectonic setting
704 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 | VI · Strong | 81 | 48 km |
| Ljubljana, Osrednjeslovenska, Slovenia | IV · Light | 53 | 153 km |
| Budapest, Budapest, Hungary | III · Weak | 37 | 317 km |
| Belgrade, Central Serbia, Serbia and Montenegro | III · Weak | 31 | 340 km |
| Vienna, Wien, Austria | III · Weak | 28 | 311 km |
| Graz, Steiermark, Austria | III · Weak | 22 | 195 km |
| Bratislava, Bratislavský, Slovakia | III · Weak | 21 | 311 km |
| Borča, Central Serbia, Serbia and Montenegro | III · Weak | 16 | 335 km |
| Dubrava, Zagreb, Croatia | VI · Strong | 14 | 48 km |
| Maribor, Podravska, Slovenia | V · Moderate | 13 | 134 km |
| Novi Sad, Vojvodina, Serbia and Montenegro | III · Weak | 13 | 282 km |
| Pécs, Baranya, Hungary | IV · Light | 12 | 169 km |
USGS PAGER estimate
Who was exposed to shaking
Modelled from the ShakeMap and population data. Alert level orange: significant casualties and damage are likely.
- VIII · Severe shaking
- 54,000 people
- VII · Very strong shaking
- 474,000 people
- VI · Strong shaking
- 1.1 million people
- V · Moderate shaking
- 2.1 million people
- IV · Light shaking
- 22 million people
- III · Weak shaking
- 44 million people
- II · Weak shaking
- 327,000 people
Estimated shaking in nearby towns
- PetrinjaPopulation 14,000VIII · Severe
- SisakcapitalPopulation 36,000VIII · Severe
- BudasevoPopulation 1,700VII · Very strong
- OresjePopulation 1,000VII · Very strong
- PokupskoPopulation 0VII · Very strong
- ZapresicPopulation 18,000VII · Very strong
- MunichcapitalPopulation 1.3 millionIII · Weak
- RomecapitalPopulation 2.3 millionIII · Weak
After the main event
Aftershocks within 100 km
USGS lists 15 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M4.9 on December 29, 2020. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.48 km ESE of Lasinja, Croatia5y ago · 24 km W of this epicenter
- 3.87 km WNW of Petrinja, Croatia5y ago · 6 km NW of this epicenter
- 4.24 km SSE of Petrinja, Croatia5y ago · 5 km SE of this epicenter
- 4.06 km NW of Petrinja, Croatia5y ago · 7 km N of this epicenter
- 4.73 km W of Petrinja, Croatia5y ago · 1 km NW of this epicenter
- 3.32 km NNW of Petrinja, Croatia5y ago · 5 km NE of this epicenter
- 4.43 km SW of Petrinja, Croatia5y ago · 1 km SE of this epicenter
- 2.7Croatia5y ago · 34 km N of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 120 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.53 km SW of Prato, ItalyMay 6, 1976 · 253 km NW of this epicenter
- 6.24 km ENE of Baška Voda, CroatiaJanuary 11, 1962 · 236 km S of this epicenter
- 6.22 km SE of Grabovci, CroatiaDecember 29, 1942 · 229 km S of this epicenter
- 6.2CroatiaJanuary 7, 1962 · 250 km S of this epicenter
- 6.1Bosnia and HerzegovinaMarch 15, 1923 · 265 km SE of this epicenter
- 6.11 km WNW of Lestans, ItalyJune 17, 1976 · 276 km W of this epicenter
- 6.14 km ENE of Trn, Bosnia and HerzegovinaOctober 27, 1969 · 102 km SE of this epicenter
- 6.15 km WSW of Jezero, Bosnia and HerzegovinaOctober 26, 1969 · 107 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 55 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 1,175 recorded deaths. The most severe:
- 1976M6.5
Ne, Balkans Nw: Slovenia: Nw
6 May 1976 · 253 km away · intensity X
978 deaths$3.6 billion damage
- 1763M6.2
Gyor; Czechoslovakia: Komarom
28 Jun 1763 · 293 km away · intensity IX
83 deathsLimited damage (under $1M)
- 1943
Bosnia-Herzegovina
29 Jan 1943 · 138 km away
19 deathsLimited damage (under $1M)
- 1930M6.0
Senigallia
30 Oct 1930 · 278 km away · intensity IX
18 deathsSevere damage ($5–24M)tsunami
- 1969M6.0
Bosnia-Herzegovina: Banja Luka
26 Oct 1969 · 100 km away · intensity VIII
14 deaths$50 million damage
- 1976M6.0
Northeastern
15 Sep 1976 · 256 km away · intensity IX
11 deathsModerate damage ($1–5M)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.