M3.5 Earthquake 10 km NW of Apollo Bay, Australia — October 21, 2023
2023-10-21 18:44:29 UTC (2023-10-21) · approx. 4:44 AM UTC+10 local
Felt by 15 people across nearby locations.
On October 21, 2023 at 18:44 UTC, a magnitude 3.5 shallow crustal earthquake struck 10 km NW of Apollo Bay, Australia, at a depth of 10.0 km and coordinates -38.6866°, 143.5866°. This earthquake was detected by 10 seismic stations with good location accuracy and was assigned a USGS significance rating of 197, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 3.5 releases seismic energy equivalent to roughly 2.7 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 157 m — a useful intuition for the size of the slip patch on the fault.
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 15 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
143.5866°E
Technical Information
Common Questions
How strong was the magnitude 3.5 earthquake near Apollo Bay, Australia?
The magnitude 3.5 earthquake that struck 10 km NW of Apollo Bay, Australia on October 21, 2023 at 18:44 UTC had a depth of 10.0 km. For context, this was a minor earthquake typically detected only by instruments.
Where did the earthquake occur?
The earthquake epicenter was located at -38.6866°, 143.5866°, which is 10 km NW of Apollo Bay, Australia.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.5 earthquakes can continue for several days and gradually diminish over time.
Authoritative source: USGS event page (event ID: us6000lh70). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, October 21, 2023). M3.5 Earthquake 10 km NW of Apollo Bay, Australia — October 21, 2023. Retrieved December 26, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lh70/