Author Question: How are mountains formed at convergent boundaries? What will be an ideal ... (Read 66 times)

ghost! · **on:** Jul 16, 2018

How are mountains formed at convergent boundaries?

What will be an ideal response?

Question 2

What is flexural isostasy? How is flexural isostasy different from the Pratt and Airy models? Use flexural isostasy to explain glacial rebound.

What will be an ideal response?

tsternbergh47 · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

At convergent plate boundaries, mountains form from crustal thickening and uplift by compression. Mass is also added by volcanic and plutonic rocks.

Answer to Question 2

Flexural isostasy describes the bending of a strong crust above a high-viscosity mantle. The Pratt and Airy models assume the crust is weak, with a low-viscosity mantle, so once glacier ice melts, the crust quickly responds. Glaciers are good examples of isostatic adjustment. The glacier adds mass, which causes subsidence of the crust below the mass, and mantle flowing away from the depression causes a small bulge adjacent to the region of subsidence. Melting removes mass and the crust returns to approximate its pre- glaciated position.