P and S waves

🏃 P wave: the first

The P (primary) wave is the fastest, about 6 km per second in the crust. It often feels like a short jolt and rarely causes serious damage.

🌊 S wave: the strong one

The S (secondary) wave travels about 3.5 km per second. It arrives later and usually brings the strongest shaking and the damage.

⏱️ The gap is time

The seconds between the P and S waves grow with distance: at 100 km it's about 12 seconds. That gap is the basis of earthquake early warning.

🧭 Use it to your advantage

If you feel a short jolt and then the motion starts to grow, don't wait: drop, cover and hold on immediately.