M4.5 Earthquake 114 km NNW of Santa Cruz da Graciosa, Portugal — July 21, 2026
2026-07-21 17:33:02 UTC (2026-07-21) · approx. 3:33 PM UTC-2 local
On July 21, 2026 at 17:33 UTC, a magnitude 4.5 shallow crustal earthquake struck 114 km NNW of Santa Cruz da Graciosa, Portugal, at a depth of 10.0 km and coordinates 40.0796°, -28.3409°. This earthquake was detected by 13 seismic stations with good location accuracy and was assigned a USGS significance rating of 312, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.5 releases seismic energy equivalent to roughly 85 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 767 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-28.3409°E
Technical Information
Common Questions
How strong was the magnitude 4.5 earthquake near Santa Cruz da Graciosa, Portugal?
The magnitude 4.5 earthquake that struck 114 km NNW of Santa Cruz da Graciosa, Portugal on July 21, 2026 at 17:33 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 40.0796°, -28.3409°, which is 114 km NNW of Santa Cruz da Graciosa, Portugal.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.5 earthquakes can continue for several days and gradually diminish over time.
Authoritative source: USGS event page (event ID: us6000tg4b). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, July 21, 2026). M4.5 Earthquake 114 km NNW of Santa Cruz da Graciosa, Portugal — July 21, 2026. Retrieved August 5, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000tg4b/