4.4

M4.4 Earthquake in the Izu Islands, Japan regionOctober 20, 2023

2023-10-20 23:07:44 UTC (2023-10-20) · approx. 8:07 AM UTC+9 local

MagnitudeM4.4(mb)
Time23:07 UTC8:07 AM UTC+9
Depth10.0 kmshallow crustal
Coordinates31.011°, 141.540°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 20, 2023 at 23:07 UTC, a magnitude 4.4 shallow crustal earthquake struck in the Izu Islands, Japan region, at a depth of 10.0 km and coordinates 31.0113°, 141.5402°.

Physical scale: An earthquake of magnitude 4.4 releases seismic energy equivalent to roughly 60 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 655 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 31.01°, 141.54°

Earthquake Details

Magnitude
4.4 mb
Depth
10.0 km
shallow crustal
Location
31.0113°N
141.5402°E

Technical Information

Event ID
us7000l67p
Event Type
earthquake
Status
✓ Reviewed
Significance
298
Stations Used
32
Azimuthal Gap
118.0°
Min Station Distance
2.559°
RMS Residual
0.45 sec
Last Updated
2023-12-26 21:25:00 UTC

Common Questions

How strong was the magnitude 4.4 earthquake in the Izu Islands, Japan region?

The magnitude 4.4 earthquake that struck in the Izu Islands, Japan region on October 20, 2023 at 23:07 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 4.4 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.4 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000l67p). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, October 20, 2023). M4.4 Earthquake in the Izu Islands, Japan regionOctober 20, 2023. Retrieved December 26, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000l67p/