The USGS has confirmed a magnitude 4.6 earthquake with its epicentre 26 km SSW of Sipí, Colombia, occurring at 20:08 UTC on Monday, September 14, 2026. The event's focal depth — 74.9 km — is a key factor in understanding how this earthquake was experienced at the surface.
Why Depth Matters
With a focal depth of 74.9 km, this earthquake falls into the intermediate depth category (70–300 km). At this depth, seismic waves travel further before reaching the surface, spreading energy over a wider area. While shaking intensity at the epicentre is somewhat reduced compared to a shallow event of equal magnitude, an intermediate earthquake can be felt across a much larger region.
Depth is one of the most critical but least discussed parameters of any earthquake. Two earthquakes of identical magnitude can have dramatically different surface effects depending on how deep the rupture originates. Significant damage can occur to vulnerable structures — particularly unreinforced masonry, old adobe buildings, and poorly maintained older construction. Well-engineered modern buildings are designed to withstand this level of shaking with minimal structural impact, though contents may shift and non-structural elements (ceilings, partitions) can be damaged.
Magnitude 4.6: What the Science Says
On the moment magnitude scale, 4.6 represents a moderate earthquake. Moderate earthquakes are felt by virtually everyone near the epicentre. Strong shaking lasting 10–30 seconds can topple unsecured items, crack plaster, and cause poorly anchored objects to fall. Aftershocks are common following moderate events.
A magnitude 4.6 earthquake releases approximately roughly 500 tonnes of TNT of energy. For comparison, this exceeds the energy released by most conventional explosive events and is sufficient to shift tectonic stress in measurable ways across a wide region.
Tectonic Setting
Peru lies along the Peru–Chile Trench where the Nazca Plate subducts beneath the South American Plate at roughly 7 cm per year, one of the fastest subduction rates on Earth. This builds enormous stress that is periodically released as powerful earthquakes.
This region's seismic history is an important reminder that earthquake risk is a long-term reality that requires sustained preparedness. Peru has experienced numerous devastating earthquakes, most notably the 1970 Ancash earthquake (M7.9, ~70,000 deaths — one of the deadliest in the Western Hemisphere) and the 2007 Pisco earthquake (M8.0). The coastal cities of Lima and Callao face significant hazard from both seismic and tsunami risks.
Practical Safety Information
Regardless of the earthquake's depth or magnitude, standard safety procedures apply. Understanding the type of building you live or work in is one of the most important steps in earthquake preparedness. Older unreinforced masonry buildings and soft-storey apartment buildings are significantly more vulnerable than modern reinforced concrete or steel-frame structures. If you have concerns, consult a structural engineer.
After an earthquake, expect aftershocks. Check yourself and others for injuries. Inspect your surroundings for hazards before moving — broken glass, gas leaks (smell), downed power lines, and structural damage. If you suspect a gas leak, open windows and evacuate without using electrical switches or open flames.
Peru's Instituto Geofísico del Perú (IGP) monitors seismic activity. INDECI (Instituto Nacional de Defensa Civil) coordinates emergency response.
Track This Event
All seismic data for this event is being updated in real time as the USGS refines its measurements. Initial magnitude and depth estimates are sometimes revised as more seismograph stations report in — a process that typically completes within hours of the event. Follow updates on our live earthquake map and consider submitting a felt report if you experienced this earthquake directly.
The Science of Seismic Monitoring
Modern earthquake detection relies on a global network of seismographs — sensitive instruments that record ground motion in all three dimensions. When an earthquake occurs, the P-waves (primary, compressional waves) arrive first, followed by the slower S-waves (secondary, shear waves), and finally the surface waves that cause the most felt shaking. By comparing arrival times at multiple stations, scientists can triangulate the earthquake's location and calculate its magnitude within minutes of the event.
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