Radar because the waves are reflected back off of the source so with the reflection it's hard for them to see earth surface.
A tributary is a source of water for creeks and is one of the few starts of the water system. It would be d
Schist has the highest metamorphic grade.
<span>Sinkholes, especially like the one that occurred in Mexico City, are often sign that the water reservoir is being depleted. Usually, the water underneath the ground helps stabilize it, however if there is suddenly open space or a cavern, it can collapse on its self causing a sink hole. This could also happen from fracking and drilling.</span>
