adjective / noun / verb
shallow
SHAL-oh/ˈʃæləʊ/
Extending only a short distance below the surface.
The man stands ankle-deep in a shallow pool with a pebbly bottom.

Etymology
Middle English schalowe already described water with little depth. It probably shares an origin with Old English sceald, the adjective behind shoal, linking shallow water with the name for a shallow place.
In context
the shallow subsurface which is only hardly say 10 meters or 60 meters or like say 200 meters not much beyond it
More examples
- Plant the seeds in shallow holes.
- Small fish gather in the shallows near the bank.
- The stream shallows as it crosses the gravel bed.
Forms
shallow · shallower · shallowest · shallows · shallowed · shallowing
shallowness noun — The condition of having little depth.
shallowly adverb — Only a short distance below the surface.
Similar words
- superficial
- Describes surface-level injuries rather than the depth of water.