Earthquake guides

Written by the Quake Tracker Live editorial team. Each guide explains one topic in plain English and points to the original sources, mainly the U.S. Geological Survey (USGS) and FEMA.

• The Earthquake Magnitude Scale Explained

  Richter versus moment magnitude, what each level feels like, and how often each size occurs.

• What to Do Before, During and After an Earthquake

  Drop, Cover and Hold On, what to do in a car or near the coast, and how to handle aftershocks.

• Earthquake Depth Explained: Why It Matters

  Shallow, intermediate and deep earthquakes, why depth changes the shaking, and how reliable the number is.

• The Largest Earthquakes in U.S. History

  From Alaska 1964 (M9.2) to Ridgecrest 2019: the biggest U.S. earthquakes with dates and USGS magnitudes.

• The 10 Largest Earthquakes in the World

  Chile 1960, Alaska 1964, Sumatra 2004, Tohoku 2011 and more: the biggest earthquakes ever recorded.

• U.S. Earthquake Zones: Where Earthquakes Happen

  San Andreas, Cascadia, Alaska, New Madrid, Utah, Hawaii and Oklahoma: why each region shakes.

• Aftershocks Explained: How Long Do They Last?

  Why aftershocks happen, Omori's law, Båth's law, how long they last and how to stay safe.

• Earthquake Preparedness Checklist

  What to keep in your emergency kit, how to make a family plan, and how to secure your home.

• Tsunamis: How Earthquakes Cause Them and the Warning Signs

  How earthquakes trigger tsunamis, the natural warning signs, official alert levels and what to do near the coast.

• Can Earthquakes Be Predicted? What Science Can and Cannot Do

  Why earthquake prediction is not possible today, and how forecasts, probabilities and early warning differ.

• Earthquake Early Warning in the U.S.: ShakeAlert and the MyShake App

  How ShakeAlert works, how to receive alerts via MyShake, Android and WEA, thresholds and warning times.

• The San Andreas Fault Explained

  Where the San Andreas runs, how fast it slips, creeping vs. locked sections, 1857, 1906 and forecasts.

• The Cascadia Subduction Zone Explained

  Cascadia's geology, the 1700 earthquake, the USGS odds, tsunami timing and what it means for the Pacific Northwest.

• The Pacific Ring of Fire Explained

  What the Ring of Fire is, why it concentrates earthquakes and volcanoes, and its largest events.

Looking for what is shaking right now? See the live earthquake map, today's earthquakes and the biggest recent quakes.