What causes differences in average elevation of continents and oceans?
Crustal thickness?
- Thickness of continental crust = 25-40 km
- Thickness of oceanic crust = 5-7 km
Crustal density?
- At surface, continental crustal rocks have low density (often about 2.6-2.7 g/cm3), but lower continental crust is more dense
- Aggregate density of continental crust is 2.8 g/cm3
- Aggregate density of oceaic crust is 2.9 g/cm3
Variation in crustal thickness is more significant factor in explaining two elevations