Notable Historic Earthquakes.

Real examples to pair with the live earthquake data layer — the map shows what's happening right now; this page shows what's happened before, tied back to the plate boundary types already explained on the Plate Tectonics page.

1960 Valdivia earthquake, Chile — magnitude 9.5. The strongest earthquake ever recorded, at a convergent boundary where the Nazca Plate subducts beneath the South American Plate — the same tectonic setting that built the Andes. Ruptured roughly 600 miles of fault and generated a tsunami felt across the entire Pacific.

1964 Alaska earthquake (Prince William Sound) — magnitude 9.2. The largest earthquake ever recorded in North America, at the subduction zone where the Pacific Plate meets the North American Plate — the same general tectonic setting as the Cascades' volcanism, just expressed as sudden fault rupture instead of eruption.

2004 Sumatra–Andaman earthquake — magnitude 9.1. Struck at a subduction zone off Indonesia, generating a tsunami that killed roughly 230,000 people across multiple countries — the single deadliest tsunami in recorded history, and a stark illustration of why subduction-zone earthquakes are disproportionately tsunami-dangerous compared to other fault types.

2011 Tōhoku earthquake, Japan — magnitude 9.0–9.1. Another subduction-zone megathrust earthquake, generating a massive tsunami that struck Japan's northeastern coast — among the most thoroughly instrumented and studied major earthquakes in history, given Japan's extensive monitoring network.

1906 San Francisco earthquake — magnitude ~7.9. A genuinely different mechanism than the four above: this struck along the San Andreas Fault, a transform boundary where the Pacific and North American plates slide past each other horizontally rather than colliding or subducting — the same boundary type explained on the Plate Tectonics page, and proof that transform boundaries can be just as destructive as convergent ones, even without a subduction zone or tsunami involved.

Worth including as a genuine counter-example: an intraplate earthquake — one that occurs nowhere near a plate boundary at all (the 1811–1812 New Madrid earthquakes in the central United States are the classic example) — as a reminder that plate-boundary tectonics explains most, but not literally all, seismic activity on Earth.