4.1

M4.1 Earthquake near southwestern Ryukyu Islands, JapanJuly 19, 2023

2023-07-19 20:26:18 UTC (2023-07-19) · approx. 4:26 AM UTC+8 local

MagnitudeM4.1(mb)
Time20:26 UTC4:26 AM UTC+8
Depth10.0 kmshallow crustal
Coordinates23.040°, 125.337°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 19, 2023 at 20:26 UTC, a magnitude 4.1 shallow crustal earthquake struck near southwestern Ryukyu Islands, Japan, at a depth of 10.0 km and coordinates 23.0396°, 125.3366°.

Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 23.04°, 125.34°

Earthquake Details

Magnitude
4.1 mb
Depth
10.0 km
shallow crustal
Location
23.0396°N
125.3366°E

Technical Information

Event ID
us7000kgyl
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
27
Azimuthal Gap
129.0°
Min Station Distance
1.673°
RMS Residual
0.59 sec
Last Updated
2023-09-28 21:33:53 UTC

Common Questions

How strong was the magnitude 4.1 earthquake near southwestern Ryukyu Islands, Japan?

The magnitude 4.1 earthquake that struck near southwestern Ryukyu Islands, Japan on July 19, 2023 at 20:26 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 4.1 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.1 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000kgyl). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, July 19, 2023). M4.1 Earthquake near southwestern Ryukyu Islands, JapanJuly 19, 2023. Retrieved September 28, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000kgyl/