Erosion Grand Canyon NP, AZ. To get a sense of erosional relief in this same area, hover the hand cursor over each Problem 2 placemark and find the relief (m) by subtracting the elevations shown at the bottom of the screen in the Information Bar. Choose one: 2,3102,340 m 1,4001,425 m 9751,000 m 3,0203,050 m.