The Science Behind Tsunamis Explained

Russia's massive 8.8 earthquake sent Hawaii scrambling for higher ground Wednesday morning. The quake disrupted normal Pacific Ocean patterns enough to trigger tsunami warnings across the islands—later downgraded to an advisory when the big waves didn't materialize.

But here's what most people get wrong about tsunamis: they're not one giant Hollywood wave. They're a series of surges that can pound coastlines for hours.

How These Monsters Form

Tsunamis need serious energy to get started. NOAA says 80% come from earthquakes, but volcanic eruptions and underwater landslides work too. Anything that suddenly moves massive amounts of water.

Yesterday's Russian quake displaced an enormous volume of ocean water. That energy shot upward and outward in all directions, creating waves that raced across the Pacific. Think of dropping a boulder in a pond—except the boulder is the size of a city and the pond is an ocean.