posted on Feb, 3 2009 @ 01:58 AM
When large areas of gound dry out, they tend to contract, leaving cracks in the ground, it happens on small and large scales.
Tunnels are tube like structures that are underground,
I see linear type depressions on the surface.
This may indicate, drying ground, if they were tunnels, they are now collapsed.
Lava tubes do not form linking tunnels in a matrix as is displayed in the image, to my knowledge.
I have seen some images that suggest frozen lakes with ice flows dusted over.
It doesn't look like them.
I am leaning towards, contracting ground formations.