4.4

M4.4 Earthquake in the Volcano Islands, Japan regionJuly 9, 2023

2023-07-09 19:30:38 UTC (2023-07-09) · approx. 5:30 AM UTC+10 local

MagnitudeM4.4(mb)
Time19:30 UTC5:30 AM UTC+10
Depth10.0 kmshallow crustal
Coordinates24.043°, 142.954°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 9, 2023 at 19:30 UTC, a magnitude 4.4 shallow crustal earthquake struck in the Volcano Islands, Japan region, at a depth of 10.0 km and coordinates 24.0429°, 142.9536°.

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.

This earthquake is part of an ongoing aftershock sequence following the magnitude 5.3 mainshock that occurred 1 day ago in the Volcano Islands, Japan region. Since the mainshock, the USGS has recorded 0 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

Map showing earthquake epicenter at 24.04°, 142.95°

Earthquake Details

Magnitude
4.4 mb
Depth
10.0 km
shallow crustal
Location
24.0429°N
142.9536°E

Technical Information

Event ID
us7000kge9
Event Type
earthquake
Status
✓ Reviewed
Significance
298
Stations Used
32
Azimuthal Gap
93.0°
Min Station Distance
13.111°
RMS Residual
0.48 sec
Last Updated
2023-09-16 19:16:19 UTC

Common Questions

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

The magnitude 4.4 earthquake that struck in the Volcano Islands, Japan region on July 9, 2023 at 19:30 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.

Is this the same earthquake as the M5.3 one earlier?

No. This magnitude 4.4 earthquake is an aftershock of the larger magnitude 5.3 mainshock that occurred earlier in the Volcano Islands, Japan region. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

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: us7000kge9). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, July 9, 2023). M4.4 Earthquake in the Volcano Islands, Japan regionJuly 9, 2023. Retrieved September 16, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000kge9/