At the end of the Pleistocene, most large mammals became extinct. All elephants, horses, camels and rhinoceroses became extinct in North America. Most of the ice sheets melted but the weather remained cooler. Technically, we are just between ice ages. As the weight of the ice was lifted from the continents, they rebounded and parts are still rising.
Tectonic activity continues throughout the world and the continents are still moving.
In North America, earthquakes and volcanic eruptions frequently rock the west coast.