M4.6 Earthquake southeast of Easter Island — December 18, 2023
2023-12-18 17:38:08 UTC (2023-12-18) · approx. 11:38 AM UTC-6 local
Aftershock of the M5.2 mainshock.
On December 18, 2023 at 17:38 UTC, a magnitude 4.6 shallow crustal earthquake struck southeast of Easter Island, at a depth of 10.0 km and coordinates -41.2818°, -90.5834°. This earthquake was detected by 31 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 326, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — a useful intuition for the size of the slip patch on the fault.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.2 mainshock that occurred 11 days ago southeast of Easter Island. Since the mainshock, the USGS has recorded 0 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
-90.5834°E
Technical Information
Common Questions
How strong was the magnitude 4.6 earthquake southeast of Easter Island?
The magnitude 4.6 earthquake that struck southeast of Easter Island on December 18, 2023 at 17:38 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -41.2818°, -90.5834°, which is southeast of Easter Island.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.2 one earlier?
No. This magnitude 4.6 earthquake is an aftershock of the larger magnitude 5.2 mainshock that occurred earlier southeast of Easter Island. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Actions
Authoritative source: USGS event page (event ID: us7000ljx8). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, December 18, 2023). M4.6 Earthquake southeast of Easter Island — December 18, 2023. Retrieved February 27, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000ljx8/