How Fast Is Earthquake P-Wave?

P-waves — primary or pressure waves — travel at 6,000 m/s through Earth's crust. They arrive seconds before the more damaging S-waves, which is exactly what earthquake early-warning systems use to give people a few critical seconds of warning.

P-waves arrive seconds before damaging S-waves — earthquake early-warning systems use this gap to alert millions before the shaking arrives.

• Faster than S-waves
• Earthquake early-warning uses this gap