We can estimate how far down the old surface used to be.

He pulled a fingernail down the surface, and felt the roughness.

The quake took place 6.6km down the surface.

He ran a finger down the cool surface of glass, the claw extended without his thinking about it.

Dark threads that were sea snakes writhed in the moonlight down the glinting surface of the water.

She sighed and let her fingers move slowly down the dark, smooth surface of the glass.

The cup hit the glass and the contents slid slowly down the surface.

Lee ran a finger down the slick surface of her desk.

Down the surface of this cliff the river flowed in a series of beautiful cascades.

Caressingly, he ran his fingers down the polished surface.