U.S. Geological Survey Earthquake Hazards Program

Regional Offices

Our scientists study locations around the world. Learn about research conducted in our regional offices, regional seismic network monitoring, and local activities of interest.

• Pacific Northwest
• Northern California
• Southern California
• Intermountain West
• Central & Eastern US
• National Earthquake Information Center
• Albuquerque Seismo Lab

Today’s Earthquake Fact

An earthquake is caused by the shaking of the ground due to an abrupt shift of rock along a fracture in the Earth, called a fault. Within seconds, an earthquake releases stress that has slowly accumulated within the rock, sometimes over hundreds of years. Most earthquakes are caused by slow movements deep in the Earth that push against the Earth's brittle, relatively thin outer layer, causing the rocks to break suddenly.