Fracking involves the injection of water containing a surfactant and various other chemicals under high pressure into a source rock e.g. shale, causing the latter to fracture and release natural gas (principally methane).

FORBES: British "Fracking" Causes Earthquake -- What Now?

At the same time Yury Boiko, the Ukrainian energy minister, has high hopes that shale gas -- formed deep underground within large shale rock formations -- could also be a major alternative source of power in the decades to come.

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