A primary factor that led to The Great Depression were the actions of the Federal Reserve and its inflationary policies. The Federal Reserve is the central bank of the United States and was created in 1913 to provide the nation with a more secure, flexible, and stable monetary system.
The lithosphere of the earth is divided into a small number of plates which float on and travel independently over the mantle and much of the earth's seismic activity occurs at the boundaries of these plates.