M4.9 Earthquake 244 km S of Vailoatai, American Samoa — December 13, 2023
2023-12-13 20:22:58 UTC (2023-12-13) · approx. 9:22 AM UTC-11 local
On December 13, 2023 at 20:22 UTC, a magnitude 4.9 shallow crustal earthquake struck 244 km S of Vailoatai, American Samoa, at a depth of 7.6 km and coordinates -16.5474°, -171.0830°. This earthquake was detected by 62 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 369, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 km — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-171.0830°E
Technical Information
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Common Questions
How strong was the magnitude 4.9 earthquake near Vailoatai, American Samoa?
The magnitude 4.9 earthquake that struck 244 km S of Vailoatai, American Samoa on December 13, 2023 at 20:22 UTC had a depth of 7.6 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -16.5474°, -171.0830°, which is 244 km S of Vailoatai, American Samoa.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 earthquakes can continue for several days and gradually diminish over time.
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Location
Authoritative source: USGS event page (event ID: us7000lirg). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, December 13, 2023). M4.9 Earthquake 244 km S of Vailoatai, American Samoa — December 13, 2023. Retrieved February 17, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000lirg/