4.) plate tectonics 10 mt. everest 8850 meters land 29.296 avg. elevation of and 840 meters level avg. depth of oceans 3729 meters margin deep ocearn trenches ocean-70.8% 10 mariana trench 11,022 meters 24 20 16 8 0 millions of square killometers percent of earth's surface 100 150 200 250 300 350 400 450 500 20 40 60 80 100 percentage of area percentages of the earth's surface at different elevations are plotted above. this is called the hypsographic curve a.) why are there two elevations that cover so much of the surface of the earth (why is there a bimodal distribution of elevations)? (4 points) b.) why is there so much of the earth's surface at or near sea-level? (3 points) c.) why haven't the tallest mountains (e. g. the himalayas) eroded down to sea-level? why haven't the deepest ocean trenches (e. g. the mariana trench) filled up with sediment? (3 points)