M6.4 Earthquake 4 km SW of Palekastro, Greece — October 12, 2021
2021-10-12 09:24:05 UTC (2021-10-12) · approx. 11:24 AM UTC+2 local
Felt by 198 people across surrounding communities. Maximum shaking intensity MMI 8.2 (violent).
On October 12, 2021 at 09:24 UTC, a magnitude 6.4 shallow crustal earthquake struck 4 km SW of Palekastro, Greece, at a depth of 20.0 km and coordinates 35.1691°, 26.2152°. The earthquake was reported felt by 198 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 8.2 (violent). The USGS PAGER system issued a yellow alert level for this event, indicating local impact possible. The nearest populated place is Palekastro (population 1,094).
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.
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
What the Shaking Felt Like
At MMI 8.2 (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 198 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 | 4,098,095 |
| MMI 4 | light | 406,640 |
| MMI 5 | moderate | 5,006 |
| MMI 6 | strong | 3,903 |
| MMI 7 | very strong | 11,571 |
| MMI 8 | severe | 2,655 |
Earthquake Details
26.2152°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 6.4 earthquake near Palekastro, Greece?
The magnitude 6.4 earthquake that struck 4 km SW of Palekastro, Greece on October 12, 2021 at 09:24 UTC had a depth of 20.0 km. It was felt by 198 people with maximum shaking intensity of MMI 8.2 (violent). For context, this was a strong earthquake capable of causing significant damage.
Where did the earthquake occur?
The earthquake epicenter was located at 35.1691°, 26.2152°, which is 4 km SW of Palekastro, Greece. The nearest populated place is Palekastro (population 1,094). View all earthquakes in Greece.
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.
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 6.4 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000ftxu). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, October 12, 2021). M6.4 Earthquake 4 km SW of Palekastro, Greece — October 12, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000ftxu/