4.3

M4.3 Earthquake 145 km ESE of Iwaki, JapanNovember 4, 2023

2023-11-04 20:34:40 UTC (2023-11-04) · approx. 5:34 AM UTC+9 local

MagnitudeM4.3(mb)
Time20:34 UTC5:34 AM UTC+9
Depth20.1 kmshallow crustal
Coordinates36.564°, 142.402°
Felt byNo felt reports
Status✓ Reviewed by USGS

On November 4, 2023 at 20:34 UTC, a magnitude 4.3 shallow crustal earthquake struck 145 km ESE of Iwaki, Japan, at a depth of 20.1 km and coordinates 36.5639°, 142.4017°.

Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 36.56°, 142.40°

Earthquake Details

Magnitude
4.3 mb
Depth
20.1 km
shallow crustal
Location
36.5639°N
142.4017°E

Technical Information

Event ID
us7000l9vp
Event Type
earthquake
Status
✓ Reviewed
Significance
284
Stations Used
23
Azimuthal Gap
149.0°
Min Station Distance
3.918°
RMS Residual
0.54 sec
Last Updated
2024-01-10 06:01:58 UTC

Common Questions

How strong was the magnitude 4.3 earthquake near Iwaki, Japan?

The magnitude 4.3 earthquake that struck 145 km ESE of Iwaki, Japan on November 4, 2023 at 20:34 UTC had a depth of 20.1 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 4.3 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.3 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000l9vp). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, November 4, 2023). M4.3 Earthquake 145 km ESE of Iwaki, JapanNovember 4, 2023. Retrieved January 10, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000l9vp/