M4.2 Earthquake in the Izu Islands, Japan region — December 30, 2021
2021-12-30 23:22:38 UTC (2021-12-30) · approx. 8:22 AM UTC+9 local
On December 30, 2021 at 23:22 UTC, a magnitude 4.2 shallow crustal earthquake struck in the Izu Islands, Japan region, at a depth of 10.0 km and coordinates 30.9772°, 142.3701°.
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.
Earthquake Details
142.3701°E
Technical Information
Common Questions
How strong was the magnitude 4.2 earthquake in the Izu Islands, Japan region?
The magnitude 4.2 earthquake that struck in the Izu Islands, Japan region on December 30, 2021 at 23:22 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 4.2 earthquakes can continue for several days and gradually diminish over time.
Actions
Location
Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000gaxq). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, December 30, 2021). M4.2 Earthquake in the Izu Islands, Japan region — December 30, 2021. Retrieved March 5, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000gaxq/