M4.8 Earthquake near Pacific-Antarctic Ridge — September 4, 2023
2023-09-04 23:16:56 UTC (2023-09-04) · approx. 1:16 PM UTC-10 local
Aftershock of the M5.1 mainshock.
On September 4, 2023 at 23:16 UTC, a magnitude 4.8 shallow crustal earthquake struck near Pacific-Antarctic Ridge, at a depth of 10.0 km and coordinates -56.0601°, -143.7612°. This earthquake was detected by 31 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 354, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.8 releases seismic energy equivalent to roughly 239 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.2 km — 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 5.1 mainshock that occurred 14 days ago near Pacific-Antarctic Ridge. 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
-143.7612°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.8 earthquake near Pacific-Antarctic Ridge?
The magnitude 4.8 earthquake that struck near Pacific-Antarctic Ridge on September 4, 2023 at 23:16 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 -56.0601°, -143.7612°, which is near Pacific-Antarctic Ridge.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.8 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.1 one earlier?
No. This magnitude 4.8 earthquake is an aftershock of the larger magnitude 5.1 mainshock that occurred earlier near Pacific-Antarctic Ridge. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Actions
Authoritative source: USGS event page (event ID: us7000ktcd). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, September 4, 2023). M4.8 Earthquake near Pacific-Antarctic Ridge — September 4, 2023. Retrieved November 17, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000ktcd/