2006-08-09 18:31:17 · 3 answers · asked by Matthew M 2 in Science & Mathematics ➔ Earth Sciences & Geology
Two reasons. First, being an inner planet, along with Mercury, Venus, and Mars, most of earth's gaseous atmosphere was blown away during the formation period, leaving the denser elements predominate. This distinguishes the inner planets from the outer gas giants like Jupiter and Saturn.
Second, while the earth cooled, the denser elements moved toward the center of the earth, which continues to generate heat, leaving the less dense materials such as basalt and granite to cool near the surface.
The earth's crust is very thin, in comparison with its 4,000 mile radius, and it basically floats atop the much warmer mantle.
2006-08-09 19:32:14 · answer #1 · answered by bpiguy 7 · 0⤊ 0⤋
The Ice age caused the rocky surface in some area's to become smooth. The ice smoothed the rock and also water creates valleys and canyons. There are alot of variables...
2006-08-10 01:39:01 · answer #2 · answered by 345Grasshopper 5 · 0⤊ 0⤋
Its solid - otherwise we wouldn't be here!!
the surface is a result of earths evolution through the millennia - the volcanic eruptions, meteor strikes et. etc. And it will continue to evolve.
2006-08-10 01:50:42 · answer #3 · answered by itponnana 2 · 0⤊ 0⤋