A seismic event measuring magnitude 4.9 has been recorded by global monitoring networks, with the epicentre located 149 km SSE of Port Blair, India. The earthquake occurred at 19:55 UTC on Tuesday, August 11, 2026 and was detected at a focal depth of 113.5 km.
Seismological Overview
Earthquakes are the result of sudden energy release in Earth's crust, most commonly along fault lines where tectonic plates interact. This energy radiates outward as seismic waves — measured and characterised by networks of seismographs operated by agencies including the USGS, JMA, EMSC, and GFZ.
India's seismic hazard stems primarily from the ongoing collision of the Indian Plate with the Eurasian Plate — a process that built the Himalayas and continues to drive intense seismicity across northern India, Nepal, and the Andaman Islands.
Event Parameters in Detail
Magnitude: 4.9 (moment magnitude scale, Mw) — a moderate earthquake.
Depth: 113.5 km
Location: 149 km SSE of Port Blair, India
Time: 19:55 UTC on Tuesday, August 11, 2026
With a focal depth of 113.5 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.
Energy and Ground Motion
A magnitude 4.9 earthquake releases approximately approximately 30,000 tonnes of TNT — comparable to the Hiroshima atomic bomb 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.
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.
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.
Regional Seismic History
Notable Indian earthquakes include the 2001 Bhuj earthquake (M7.7, ~20,000 deaths) in Gujarat and the 2015 Gorkha earthquake centred in Nepal (M7.8, ~9,000 deaths) which was strongly felt across northern India. The densely populated Indo-Gangetic Plain, though not directly on a plate boundary, faces amplified shaking from distant Himalayan earthquakes.
Public Safety Guidance
For residents in the affected area, the immediate priority is assessing personal safety and structural integrity. Keep an earthquake emergency kit accessible at home. It should include at least 72 hours of water (4 litres per person per day), non-perishable food, a first aid kit, torch, battery-powered radio, copies of important documents, and essential medications. Reviewing and restocking this kit annually is strongly recommended.
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.
The National Center for Seismology (NCS) under India's Ministry of Earth Sciences monitors seismic activity and maintains a network of ~100 seismograph stations across the country.
Continued Monitoring
The USGS and regional seismic networks will continue to monitor this event for aftershock activity. QuakeWatch aggregates this global data in real time — you can view all current seismic activity on our live map, or explore our earthquake science guides to learn more about the forces behind events like this one.
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