Real-time coverage of earthquake event — 275 km SW of Houma, Tonga — Pandita Data.
🌍 OPEN LIVE 3D EARTHQUAKE MAPA magnitude 5.7 earthquake struck 275 km southwest of Houma, Tonga, on May 12, 2026 at 21:19 UTC, at a depth of 154 km. The U.S. Geological Survey issued a GREEN PAGER alert—indicating minimal expected impact—and no tsunami warning was issued. Despite the moderate magnitude, the significant depth and remote epicenter location mean ground shaking was likely not felt by populated areas, but this event underscores Tonga's position atop one of Earth's most seismically active subduction zones.
Tonga sits directly above the Tonga Trench, where the Pacific Plate subducts (descends) beneath the Indo-Australian Plate at a rate of approximately 24 cm per year—among the fastest subduction rates globally. This collision zone generates the majority of Tonga's earthquakes. The 154 km focal depth places this rupture within the subducting Pacific slab itself, not at the plate interface. These intraslab events occur as the cold, brittle oceanic crust fractures under intense pressure and stress during its descent into the mantle.
At magnitude 5.7 and 154 km depth, this earthquake released approximately 3.5 × 1013 joules of energy—equivalent to roughly 8,400 metric tons of TNT. The rupture occurred well below the shallow megathrust interface (typically 20–50 km depth), where the largest tsunamigenic earthquakes originate. Intraslab ruptures at this depth generate seismic waves that travel through solid rock rather than displacing the seafloor, explaining the absence of tsunami generation.
Deep focus earthquakes (>70 km) attenuate (weaken) more rapidly with distance. At 154 km, seismic energy dissipates significantly before reaching the surface. A 5.7 magnitude event at shallow depth might cause moderate damage; at 154 km, it produces distant, weak ground motion detectable mainly by seismometers.
Houma and Nuku'alofa, Tonga's capital (~280 km away), experienced minimal to imperceptible shaking. However, the Tonga archipelago lies in a tsunami-prone region where larger (M 7.0+) subduction interface earthquakes have generated destructive waves historically. The 2004 Tongan earthquakes and the 2022 Hunga Tonga-Hunga Ha'apai submarine eruption and associated tsunami killed over 3,600 regionally, reinforcing the need for robust early warning systems. This moderate intraslab event serves as a seismic reminder of ongoing plate convergence.
Explore the mechanics of this subduction-zone earthquake and observe Pacific Plate dynamics in real time using Pandita Data's 3D earthquake simulation, powered by live USGS seismic feeds and plate-boundary models.
FAQ::[ { "q": "What caused this earthquake?", "a": "Intraslab rupture within the Pacific Plate as it subducts beneath Indo-Australia at Tonga Trench. 154 km depth indicates stress fracture deep in the descending slab, not megathrust interface." }, { "q": "Is a tsunami risk associated with this event?", "a": "No. Deep intraslab earthquakes (