How Fast Is Magma Rising?

Magma rises through volcanic conduits at roughly 1 km/h in the final minutes before an eruption — fast enough that modern satellites can detect the ground deformation hours ahead. The motion is one of the most reliable eruption warning signs.

Modern satellites can detect rising magma before any visible signs of eruption appear.

• Same pace as a Foucault pendulum
• Detectable by satellites hours before eruption