Earthquakes are caused by the sudden movement of tectonic plates under the earth's crust. The 1906 San Francisco earthquake, one of the worst natural disasters in U.S. history, occurred at 5:12am on April 18, 1906 and measured 8.3 on the Richter scale, affecting 375,000 square miles, half of which were in the Pacific Ocean. The earthquake was caused by the sliding and hitting of the tectonic plates at the edges of the earth's crust under San Francisco.

1. What is an earthquake Earthquake is a shaking of the ground caused by sudden movement of the tectonic plates under ground

2. What causes Earthquakes …as the tectonic plates on the earth’s crust move they often hit each other at the edges. The tectonic plates are sliding past each other.

3. Specific Earthquake San francisco 1906 5:12am – April 18,1906 Ranked as one of the worst natural disasters in the history of U.S.A and one of the most significant earthquakes of all times.

4. PACIFIC OCEAN The American earthquake affected 375,000 square miles , half of which were in the Pacific ocean.

5. Created By Matt Information found: On Google From Massey