Science crossword puzzle

1. Numerical measure of a line's inclination relative to the horizontal.
4. the vertical distance or difference in elevation between contour lines.
6. a landform that rises at least 1,000 feet (300 meters) or more above its surrounding area.
9. the line of 0° longitude, the starting point for measuring distance both east and west around Earth.
10. a flat, elevated landform that rises sharply above the surrounding area on at least one side.
11. The vertical distance between a standard reference point, such as sea level, and the top of an object or point on the Earth, such as a mountain.
13. a broad area of relatively flat land.
14. the term used for the differences in height from place to place on the land's surface
15. features on the Earth's surface that make up the terrain

2. measures distance east or west of the prime meridian.
3. an imaginary line around the middle of a planet or other celestial body.
5. a line drawn on a topographic map to indicate ground elevation or depression.
7. A representation of a region of three-dimensional space, such as of the Earth or a part of the universe, usually on a two-dimensional plane surface.
8. measures the distance north or south of the equator.
12. The three-dimensional arrangement of physical attributes (such as shape, height, and depth) of a land surface in a place or region.