M4.3 Earthquake near Pacific-Antarctic Ridge — October 15, 2023
2023-10-15 23:59:08 UTC (2023-10-15) · approx. 1:59 PM UTC-10 local
On October 15, 2023 at 23:59 UTC, a magnitude 4.3 shallow crustal earthquake struck near Pacific-Antarctic Ridge, at a depth of 10.0 km and coordinates -56.0565°, -143.4194°.
Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 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 5.1 mainshock that occurred 11 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
-143.4194°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.3 earthquake near Pacific-Antarctic Ridge?
The magnitude 4.3 earthquake that struck near Pacific-Antarctic Ridge on October 15, 2023 at 23:59 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 4.3 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 4.3 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.
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Understanding This Data
Magnitude 4.3 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000lgv8). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, October 15, 2023). M4.3 Earthquake near Pacific-Antarctic Ridge — October 15, 2023. Retrieved December 26, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lgv8/