M3.9 Earthquake in the Maug Islands region, Northern Mariana Islands — December 18, 2021
2021-12-18 21:47:52 UTC (2021-12-18) · approx. 7:47 AM UTC+10 local
On December 18, 2021 at 21:47 UTC, a magnitude 3.9 intermediate depth earthquake struck in the Maug Islands region, Northern Mariana Islands, at a depth of 189.9 km and coordinates 19.0125°, 145.6641°.
Physical scale: An earthquake of magnitude 3.9 releases seismic energy equivalent to roughly 11 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 296 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
145.6641°E
Technical Information
Common Questions
How strong was the magnitude 3.9 earthquake in the Maug Islands region, Northern Mariana Islands?
The magnitude 3.9 earthquake that struck in the Maug Islands region, Northern Mariana Islands on December 18, 2021 at 21:47 UTC had a depth of 189.9 km. For context, this was a minor earthquake typically detected only by instruments.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.9 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.9 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000gekm). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, December 18, 2021). M3.9 Earthquake in the Maug Islands region, Northern Mariana Islands — December 18, 2021. Retrieved March 1, 2022 from https://www.earthquaketracker.org/earthquakes/event/us6000gekm/