Which one has a greater force acting on the earth's crust under the Andes Mountains or the Appalachian Mountains?

The Andes Mountains experience greater tectonic forces acting on the Earth's crust compared to the Appalachian Mountains. This is primarily due to the Andes being located at a convergent boundary where the Nazca Plate is being subducted beneath the South American Plate, resulting in significant geological activity and uplift. In contrast, the Appalachians are much older and formed from ancient tectonic processes, leading to less current tectonic force. Thus, the Andes are still actively shaped by powerful geological forces.