90° S
Explanation
The geographic coordinate system uses latitude and longitude to define locations on Earth. Latitude measures the angular distance north or south of the Equator, ranging from 0° to 90°.
Analysis of Options:
- 0° is incorrect: 0° latitude represents the Equator, which is the great circle dividing the Earth into the Northern and Southern Hemispheres.
- 90° N is incorrect: 90° N represents the North Pole, the northernmost point on the Earth's axis of rotation.
- 90° S is correct: 90° S represents the South Pole, the southernmost point on the Earth's axis of rotation.
- 180° S is incorrect: Latitude values are limited to a maximum of 90° (North or South). The coordinate 180° refers to longitude (specifically the antimeridian or International Date Line), not latitude.
Key Takeaway:
The South Pole is geographically defined as 90° S latitude. The North Pole is 90° N, and the Equator is 0°.