M6.4 Earthquake 2 km WSW of Petrinja, Croatia — December 29, 2020
2020-12-29 11:19:54 UTC (2020-12-29) · approx. 12:19 PM UTC+1 local
Felt by 1,782 people across a wide area. Maximum shaking intensity MMI 9.0 (violent).
On December 29, 2020 at 11:19 UTC, a magnitude 6.4 shallow crustal earthquake struck 2 km WSW of Petrinja, Croatia, at a depth of 10.0 km and coordinates 45.4244°, 16.2573°. The earthquake was reported felt by 1,782 peopleacross a wide area, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 9.0 (violent). The USGS PAGER system issued a orange alert level for this event, indicating regional impact possible. The nearest populated place is Petrinja (population 13,868).
Physical scale: An earthquake of magnitude 6.4 releases seismic energy equivalent to roughly 60 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 16 km — a useful intuition for the size of the slip patch on the fault.
Nearest Populated Places
What the Shaking Felt Like
At MMI 9.0 (violent), people in the most strongly affected areas would have experienced: Severe shaking causing considerable damage. Buildings may shift off foundations. Walls crack and may partially collapse. Heavy furniture overturned.
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 1,782 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Population exposure (USGS PAGER)
Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.
| Shaking intensity (MMI) | Description | Population exposed |
|---|---|---|
| MMI 3 | weak | 43,719,302 |
| MMI 4 | light | 22,186,592 |
| MMI 5 | moderate | 2,135,278 |
| MMI 6 | strong | 1,063,537 |
| MMI 7 | very strong | 473,865 |
| MMI 8 | severe | 54,150 |
Earthquake Details
16.2573°E
Technical Information
Common Questions
How strong was the magnitude 6.4 earthquake near Petrinja, Croatia?
The magnitude 6.4 earthquake that struck 2 km WSW of Petrinja, Croatia on December 29, 2020 at 11:19 UTC had a depth of 10.0 km. It was felt by 1,782 people with maximum shaking intensity of MMI 9.0 (violent). For context, this was a strong earthquake capable of causing significant damage.
Where did the earthquake occur?
The earthquake epicenter was located at 45.4244°, 16.2573°, which is 2 km WSW of Petrinja, Croatia. The nearest populated place is Petrinja (population 13,868).
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 6.4 earthquakes can continue for weeks to months and gradually diminish over time.
Authoritative source: USGS event page (event ID: us6000d3zh). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, December 29, 2020). M6.4 Earthquake 2 km WSW of Petrinja, Croatia — December 29, 2020. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000d3zh/