But I believe most of these are distress calls originating from subterranean sources.

The subterranean source of the Danube rose only a short distance away.

My uncle reckoned upon a fresh supply from subterranean sources, but hitherto we had met with none.

The water was apparently hotter than that of the lake - perhaps nearer its subterranean source of heat.

Oasis cultivation drew its water from subterranean sources and so was not dependent on rains.

Marsh-gas from subterranean sources occurs; one has been burning continuously since 1936.

That water must have come up from subterranean sources more than a mile and a half under the surface.

The subterranean source most be far beneath the surface, he reasoned.