Burying a gate question

In multiple instances we see example of people burying their gates in order to make them unreachable. We have also seen multiple instances of buried gates not being able to connect when dialed. Given this, how were they able to dial into the gate that had been buried after the meteor strike in "100 days"? The gate is clearly buried and yet they are able to dial in, use the kwoosh to hollow at a cavity and then transit through to the other side. Is this just an inconsistency or is there an explanation for this? Thanks!!