Seismic mapping of North America has revealed that an ancient slab of crust buried beneath the Midwest is causing the crust ...

This map shows seismic speed in the Earth’s crust at 200 kilometers depth across the continental United States and portions of Central America and Canada. The North American craton (outlined in ...

North America is the third largest continent in the world. It is located in the Northern Hemisphere. The north of the continent is within the Arctic Circle and the Tropic of Cancer passes through ...