M4.2 Earthquake 43 km SSW of Puerto El Triunfo, El Salvador — July 28, 2026
2026-07-28 04:16:09 UTC (2026-07-28) · approx. 10:16 PM UTC-6 local
On July 28, 2026 at 04:16 UTC, a magnitude 4.2 intermediate depth earthquake struck 43 km SSW of Puerto El Triunfo, El Salvador, at a depth of 70.0 km and coordinates 12.8991°, -88.6307°.
Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 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 5.5 mainshock that occurred 5 days ago 69 km SSW of Chirilagua, El Salvador. 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
-88.6307°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.2 earthquake near Puerto El Triunfo, El Salvador?
The magnitude 4.2 earthquake that struck 43 km SSW of Puerto El Triunfo, El Salvador on July 28, 2026 at 04:16 UTC had a depth of 70.0 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 4.2 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.5 one earlier?
No. This magnitude 4.2 earthquake is an aftershock of the larger magnitude 5.5 mainshock that occurred earlier 69 km SSW of Chirilagua, El Salvador. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000tgaa). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, July 28, 2026). M4.2 Earthquake 43 km SSW of Puerto El Triunfo, El Salvador — July 28, 2026. Retrieved August 4, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000tgaa/