Examples from the Web for sub-surface
Broad completely misses the point that sub-surface demolition makes plugging the well “from the top” unnecessary.
Both surface and sub-surface storage sometimes hold the water from the streams at times when it might be advantageously used.
The sub-surface structure, even though complex, can be readily read from one of these surface maps.
The only safe thing appears to be the sub-surface irrigation plan, for which, fortunately, there is plenty of room on our lot.The House that Jill Built|E. C. Gardner
About three inches below the soft snow was a sub-surface crust strong enough to carry the bodily weight.My Attainment of the Pole|Frederick A. Cook
In addition, there are indicated the sub-surface contours of one or more of the coal seams which are selected as datum horizons.