M4.9 Earthquake west of Macquarie Island — May 21, 2023
2023-05-21 23:44:20 UTC (2023-05-21) · approx. 8:44 AM UTC+9 local
On May 21, 2023 at 23:44 UTC, a magnitude 4.9 shallow crustal earthquake struck west of Macquarie Island, at a depth of 10.0 km and coordinates -52.0046°, 138.9893°. This earthquake was detected by 19 seismic stations with good 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
138.9893°E
Technical Information
Common Questions
How strong was the magnitude 4.9 earthquake west of Macquarie Island?
The magnitude 4.9 earthquake that struck west of Macquarie Island on May 21, 2023 at 23:44 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 -52.0046°, 138.9893°, which is west of Macquarie Island.
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.
Actions
Authoritative source: USGS event page (event ID: us6000kdt6). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, May 21, 2023). M4.9 Earthquake west of Macquarie Island — May 21, 2023. Retrieved January 18, 2024 from https://www.earthquaketracker.org/earthquakes/event/us6000kdt6/