Necessity is the mother of invention, as they say, and some Russians have created an ingenious though not entirely elegant solution for traversing these mud pits. Called an On-Ground Ferry ...

Underlying the rims and flanks of the mud volcanoes, they deciphered a series of normal faults — formed when one part of the ground sank relative to another — with displacements of tens of metres.

"You'll look at some features [from space] and you won't know for sure whether they are the result of lava flows or mud flows. "Without a geologist on the ground to hit them with a hammer ...