Seismologists have never had a better understanding of earthquakes. But tragedy after tragedy shows that quakes still surprise and shock people with their mercurial behavior. Precise predictions of when and where quakes will occur, and how deadly they may be, are not yet possible. If, however, researchers could chronicle how quakes grow, they might be able to better forecast how powerful they will become.

The mightiest quakes are far from instantaneous. They can last minutes, which makes them less like a single subterranean blast and more like a series of explosions moving outward. A new study, published on Wednesday in Science Advances, explains that the outward journey of these explosions differs depending on the power of the quake.

That means that the final magnitude of a quake could be determined in as little as 10 to 15 seconds after it begins, and long before it ends.

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A single-digit leap in earthquake magnitude means that 32 times more energy is being released. Many factors determine the hazard level of a quake, but small increases in magnitude can make the difference between merely damaging and catastrophic. If final earthquake magnitudes could be ascertained early on, it would give rapid, more precise warnings to populations yet to be shaken.