6.3

M6.3 Earthquake 9 km W of Týrnavos, Greece — March 3, 2021

2021-03-03 10:16:09 UTC (2021-03-03) · approx. 11:16 AM UTC+1 local

Felt by 137 people across surrounding communities. Maximum shaking intensity MMI 7.8 (severe).

MagnitudeM6.3(mww)
Time10:16 UTC≈ 11:16 AM UTC+1
Depth8.0 kmshallow crustal
Coordinates39.755°, 22.176°
Felt by137DYFI responses· max MMI 7.8
Status✓ Reviewed by USGS· yellow PAGER
yellow Alert— local impact possible

On March 3, 2021 at 10:16 UTC, a magnitude 6.3 shallow crustal earthquake struck 9 km W of Týrnavos, Greece, at a depth of 8.0 km and coordinates 39.7546°, 22.1757°. The earthquake was reported felt by 137 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 7.8 (severe). The USGS PAGER system issued a yellow alert level for this event, indicating local impact possible. The nearest populated place is Tyrnavos (population 10,796).

Physical scale: An earthquake of magnitude 6.3 releases seismic energy equivalent to roughly 43 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 13 km — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in Greece, a region characterized by the Hellenic subduction zone, where the African Plate subducts northward beneath the Aegean at roughly 35 mm per year. The nearest mapped fault system is the Hellenic Trench. View all earthquakes in Greece.

Learn more: Magnitude scale · Aftershock sequences

Nearest Populated Places

Tyrnavospop. 10,796
MMI 6.9 (very strong)
Zarkospop. 1,407
MMI 6.9 (very strong)
Giannoulipop. 7,885
MMI 6.7 (very strong)
Ampelonapop. 5,961
MMI 6.6 (very strong)
Larisapop. 144,651
MMI 6.5 (very strong)
Falannapop. 3,987
MMI 6.5 (very strong)

What the Shaking Felt Like

At MMI 7.8 (severe), people in the most strongly affected areas would have experienced: Very strong shaking. Difficult to stand. Damage to weak structures; slight damage to well-built structures. Furniture broken. Fallen plaster and loose bricks.

Map showing earthquake epicenter at 39.75°, 22.18°

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.

USGS ShakeMap intensity contours for the M6.3 earthquake near 9 km W of Týrnavos, Greece

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 137 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M6.3 earthquake near 9 km W of Týrnavos, Greece

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)DescriptionPopulation exposed
MMI 3weak18,242,176
MMI 4light1,079,966
MMI 5moderate175,456
MMI 6strong142,341
MMI 7very strong124,471
MMI 8severe519

Earthquake Details

Magnitude
6.3 mww
Depth
8.0 km
shallow crustal
Location
39.7546°N
22.1757°E
Felt Reports
137
DYFI responses
Intensity (MMI)
7.8
severe
Community Intensity
9.1
CDI from reports

Technical Information

Event ID
us7000df40
Event Type
earthquake
Status
✓ Reviewed
Significance
775
Azimuthal Gap
17.0°
Min Station Distance
0.423°
RMS Residual
0.55 sec
Last Updated
2025-12-22 19:06:42 UTC

Common Questions

How strong was the magnitude 6.3 earthquake near Týrnavos, Greece?

The magnitude 6.3 earthquake that struck 9 km W of Týrnavos, Greece on March 3, 2021 at 10:16 UTC had a depth of 8.0 km. It was felt by 137 people with maximum shaking intensity of MMI 7.8 (severe). For context, this was a strong earthquake capable of causing significant damage.

Where did the earthquake occur?

The earthquake epicenter was located at 39.7546°, 22.1757°, which is 9 km W of Týrnavos, Greece. The nearest populated place is Tyrnavos (population 10,796). View all earthquakes in Greece.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 6.3 earthquakes can continue for weeks to months and gradually diminish over time.

Has Greece had earthquakes this big before?

The largest recorded earthquake in Greece was the M8.5 Crete earthquake of June 29, 1303. Today's magnitude 6.3 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us7000df40). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, March 3, 2021). M6.3 Earthquake 9 km W of Týrnavos, Greece — March 3, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000df40/