4.2

M4.2 Earthquake 4 km SSE of San Terenziano, ItalySeptember 20, 2025

2025-09-20 21:11:40 UTC (2025-09-20) · approx. 10:11 PM UTC+1 local

MagnitudeM4.2(mb)
Time21:11 UTC10:11 PM UTC+1
Depth10.0 kmshallow crustal
Coordinates42.827°, 12.492°
Felt by6DYFI responses
Status✓ Reviewed by USGS

On September 20, 2025 at 21:11 UTC, a magnitude 4.2 shallow crustal earthquake struck 4 km SSE of San Terenziano, Italy, at a depth of 10.0 km and coordinates 42.8270°, 12.4921°.

Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 42.83°, 12.49°

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 6 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 M4.2 earthquake near 4 km SSE of San Terenziano, Italy

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
4.2 mb
Depth
10.0 km
shallow crustal
Location
42.8270°N
12.4921°E
Felt Reports
6
DYFI responses
Community Intensity
2.7
CDI from reports

Technical Information

Event ID
us7000qxli
Event Type
earthquake
Status
✓ Reviewed
Significance
273
Stations Used
48
Azimuthal Gap
72.0°
Min Station Distance
0.436°
RMS Residual
1.16 sec
Last Updated
2025-12-06 16:00:25 UTC

Common Questions

How strong was the magnitude 4.2 earthquake near San Terenziano, Italy?

The magnitude 4.2 earthquake that struck 4 km SSE of San Terenziano, Italy on September 20, 2025 at 21:11 UTC had a depth of 10.0 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 4.2 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: us7000qxli). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, September 20, 2025). M4.2 Earthquake 4 km SSE of San Terenziano, ItalySeptember 20, 2025. Retrieved May 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000qxli/