4.0

M4.0 Earthquake 111 km SW of Kastrí, GreeceOctober 12, 2025

2025-10-12 23:11:16 UTC (2025-10-12) · approx. 1:11 AM UTC+2 local

MagnitudeM4.0(mb)
Time23:11 UTC1:11 AM UTC+2
Depth35.0 kmshallow crustal
Coordinates34.059°, 23.306°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 12, 2025 at 23:11 UTC, a magnitude 4.0 shallow crustal earthquake struck 111 km SW of Kastrí, Greece, at a depth of 35.0 km and coordinates 34.0590°, 23.3056°.

Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 34.06°, 23.31°

Earthquake Details

Magnitude
4.0 mb
Depth
35.0 km
shallow crustal
Location
34.0590°N
23.3056°E

Technical Information

Event ID
us6000rgsf
Event Type
earthquake
Status
✓ Reviewed
Significance
246
Stations Used
46
Azimuthal Gap
186.0°
Min Station Distance
3.309°
RMS Residual
0.79 sec
Last Updated
2026-01-01 23:11:11 UTC

Common Questions

How strong was the magnitude 4.0 earthquake near Kastrí, Greece?

The magnitude 4.0 earthquake that struck 111 km SW of Kastrí, Greece on October 12, 2025 at 23:11 UTC had a depth of 35.0 km. For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.0 earthquakes can continue for several days and gradually diminish over time.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: us6000rgsf). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, October 12, 2025). M4.0 Earthquake 111 km SW of Kastrí, GreeceOctober 12, 2025. Retrieved May 27, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000rgsf/