DESC: You can move through solid earth. Speed is determined by a movement of 1 meter (3.28 feet) per level bought and is an independent movement from size, land speed or air speed.
The type of earth you move through can also hamper movement. Soft earth has no movement restrictions, hard earth -20 cm (-7.87 in), stone -40 cm (-15.75 in), metal -80 cm (-31.5 in).
So with 2 levels of movement you will move through soft earth at 2 meters per turn max. Hard earth will slow you down to 1.8 meters (70.86 in). Stone will further resist your movement to 1.6 meters (62.99 in). Metal would have a max movement of 1.2 meters (47.24 in)
Composite structures always slow movement to the hightest level provided that the user is not smaller than the median spacing of the structure. For example, if a wall is made from concrete and rebarb with the rebarb spaced 60 centimeters (23.63 inches) apart then a small or larger creature with this power would be slowed as if moving through metal. For any creature smaller than this 60 centimeters can move between the rebarb and is only resisted for moving through the concrete (stone).
While you are moving through earth you do not have an immunity to suffocation. If you do not have a power like breathless then you must treat moving through the earth like moving through water for a air breather.