Of, relating to, or situated in an area beneath a surface, especially the surface of the earth or of a body of water. (adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "subsurface" in a sentence
"I can see how a trip to Mars could stimulate us to push spaceflight tech but having spent a tremendous amount of dough getting to Mars and having established that there was and possibly is water on Mars and maybe even microorganisms in subsurface seas, what then?"
"Among their early findings: a surprising amount of water moves rapidly through fractures in subsurface bedrock during high-intensity storms, playing a greater role in raising pore pressure than had been thought and creating "hot spots" that can fail."
"The cold, lightless and energy-poor conditions under the seafloor provide a promising research analog for the harsh conditions in subsurface Martian soil or near hydrothermal vents on Europa, Jupiter’s second moon."