Calc Chrono Trigger - Queen Zeal summons Lavos

11:25

After Queen Zeal is defeated, she summons Lavos from the core of the planet to attack the heroes. Thanks to Chrono Trigger Next Gate, we can hard confirm that Lavos was resting in the very core of the planet.
The Earth has a radius of 6378km. This should be more or less straight forward.
Timeframe is 48 seconds.

T = 6378km/48s
= 132875/340.29
= Mach 390.475771

Final Results
Lavos rises to the surface = Mach 390.476