4.0

M4.0 Earthquake in the Izu Islands, Japan regionApril 8, 2023

2023-04-08 18:48:03 UTC (2023-04-08) · approx. 3:48 AM UTC+9 local

MagnitudeM4.0(mb)
Time18:48 UTC3:48 AM UTC+9
Depth379.1 kmdeep-focus
Coordinates29.934°, 139.168°
Felt byNo felt reports
Status✓ Reviewed by USGS

On April 8, 2023 at 18:48 UTC, a magnitude 4.0 deep-focus earthquake struck in the Izu Islands, Japan region, at a depth of 379.1 km and coordinates 29.9345°, 139.1684°.

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 29.93°, 139.17°

Earthquake Details

Magnitude
4.0 mb
Depth
379.1 km
deep-focus
Location
29.9345°N
139.1684°E

Technical Information

Event ID
us6000k2wd
Event Type
earthquake
Status
✓ Reviewed
Significance
246
Stations Used
155
Azimuthal Gap
54.0°
Min Station Distance
3.218°
RMS Residual
0.47 sec
Last Updated
2023-06-13 03:12:21 UTC

Common Questions

How strong was the magnitude 4.0 earthquake in the Izu Islands, Japan region?

The magnitude 4.0 earthquake that struck in the Izu Islands, Japan region on April 8, 2023 at 18:48 UTC had a depth of 379.1 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 4.0 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.0 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000k2wd). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, April 8, 2023). M4.0 Earthquake in the Izu Islands, Japan regionApril 8, 2023. Retrieved June 13, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000k2wd/