How does isostasy relate to active geologic processes?

Question

What will be an ideal response?

Answer 1

Answer: Isostatic adjustments to changes in crustal weight and thickness cause vertical motion of the crust. Compressional stress that shortens the crust also thickens it, causing isostatic uplift of the mountains. Tensional stress thins crust, causing isostatic subsidence of sedimentary basins. Isostasy causes crust beneath eroding mountains to rise slowly even though the overall elevations decrease, because the weight of the crust decreases as the mountains erode. The eroded sediment accumulated in sedimentary basins, causing subsidence. Slow flexural isostatic adjustment to changing weight is well documented by the patterns of recent and ongoing uplift and subsidence in eastern North America, which are attributed to glacial rebound. Isostatic movement of the crust causes movement along old faults, thereby accounting for earthquakes that occur far from plate boundaries.