4.2

M4.2 Earthquake in the Volcano Islands, Japan regionOctober 31, 2021

2021-10-31 19:18:42 UTC (2021-10-31) · approx. 5:18 AM UTC+10 local

MagnitudeM4.2(mb)
Time19:18 UTC5:18 AM UTC+10
Depth136.4 kmintermediate depth
Coordinates22.268°, 143.474°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 31, 2021 at 19:18 UTC, a magnitude 4.2 intermediate depth earthquake struck in the Volcano Islands, Japan region, at a depth of 136.4 km and coordinates 22.2682°, 143.4739°.

Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 22.27°, 143.47°

Earthquake Details

Magnitude
4.2 mb
Depth
136.4 km
intermediate depth
Location
22.2682°N
143.4739°E

Technical Information

Event ID
us7000frh2
Event Type
earthquake
Status
✓ Reviewed
Significance
271
Azimuthal Gap
54.0°
Min Station Distance
4.947°
RMS Residual
0.84 sec
Last Updated
2024-01-17 22:22:46 UTC

Common Questions

How strong was the magnitude 4.2 earthquake in the Volcano Islands, Japan region?

The magnitude 4.2 earthquake that struck in the Volcano Islands, Japan region on October 31, 2021 at 19:18 UTC had a depth of 136.4 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 4.2 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.2 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000frh2). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, October 31, 2021). M4.2 Earthquake in the Volcano Islands, Japan regionOctober 31, 2021. Retrieved January 17, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000frh2/