M4.9 Earthquake in the Revilla Gigedo Islands region — September 21, 2020
2020-09-21 09:00:01 UTC (2020-09-21) · approx. 2:00 AM UTC-7 local
On September 21, 2020 at 09:00 UTC, a magnitude 4.9 shallow crustal earthquake struck in the Revilla Gigedo Islands region, at a depth of 10.0 km and coordinates 19.6802°, -109.4142°.
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
-109.4142°E
Technical Information
Common Questions
How strong was the magnitude 4.9 earthquake in the Revilla Gigedo Islands region?
The magnitude 4.9 earthquake that struck in the Revilla Gigedo Islands region on September 21, 2020 at 09:00 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 19.6802°, -109.4142°, which is in the Revilla Gigedo Islands region.
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: us7000bqpl). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, September 21, 2020). M4.9 Earthquake in the Revilla Gigedo Islands region — September 21, 2020. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000bqpl/