earth's surface; ground surface
Refers to the surface of the earth or ground, often in geographic, scientific, or descriptive contexts.
The temperature of the earth's surface is rising.
We dug down to about 10 meters below the ground surface.
Part of the sunlight passes through the atmosphere and reaches the earth's surface.
Volcanic ash covered a wide area of the earth's surface.
The temperature dropped suddenly near the earth's surface.
地上 emphasizes being above ground level (as opposed to underground or in the air), while 地表 focuses on the physical layer forming the earth's outer surface.
地表 refers to the surface of the earth, while 地中 refers to what lies beneath it, inside the ground.
Compound of 地 (earth, ground) and 表 (surface).