Scientists have direct evidence of Earth's structure to which level?
A)The inner core.
B)The upper mantle (~250 km).
C)About 2 km from the surface.
D)10 km from the surface,based on the deepest well shaft.

Question

Quizplus · Accepted Answer

The deepest hole ever drilled by humans is the Kola Superdeep Borehole, which reached a depth of about 12 km. However, this is only a tiny fraction of the Earth's radius, which is about 6,371 km. Therefore, scientists have direct evidence of Earth's structure to a depth of about 2 km from the surface.

Scientists Have Direct Evidence of Earth's Structure to Which Level