Using the change in elevation from the rim to the river (2,085 m and 734 m, respectively, from the y-axis) and assuming that Hutton’s principle of uniformitarianism applies for erosion of the Grand Canyon, use an average downcutting erosion rate of 0.5 mm/yr to calculate a rough estimate for how long it might have taken to carve the Grand Canyon.

Which statement best explains the relationship between an area's geography and the temperature of its surface water? areas at low altitudes have the warmest water because they receive the most direct sunlight. areas at low altitudes have the warmest water because they have the least change in temperature throughout the year. areas at high latitudes have the warmest water because their days are the longest. areas at high latitudes have the warmest water because they have the longest seasons.