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What Happens During an Earthquake?

What causes earthquakes, and what types of earthquakes are there? To answer these questions, it is first helpful to have an understanding of Earth's composition.

How Are Earthquakes Measured?

Two different viewpoints underpin the most important measurements related to earthquakes: magnitude and intensity. To scientists, an earthquake is an event inside the earth. To the rest of us, it is an extraordinary movement of the ground. Magnitude measures the former, while intensity measures the latter.

Can Seismologists Predict Earthquakes?

It is not currently possible to predict exactly when and where an earthquake will occur, nor how large it will be. However, seismologists can estimate where earthquakes may be likely to strike by calculating probabilities and forecasts.

How Could a Major Earthquake Affect Urban Infrastructure?

Megacities are especially vulnerable to earthquakes. Learn about cascading effects and how modeling can minimize the risk of a natural hazard turning into a disaster.

What Happens to Buildings During Earthquakes?

Find out how earthquakes affect houses, high-rises, and other buildings, and which are considered the safest and most dangerous places to be.

How Do We Know What Makes a Building Earthquake Resistant?

Learn how the Community Seismic Network gathers data about how the ground and buildings move to inform safer construction and better damage detection.

EARTHQUAKE PREPAREDNESS

How Do Earthquake Early Warning Systems Work?

Earthquake early warning systems don't predict earthquakes. Instead, they detect ground motion as soon as an earthquake begins and quickly send alerts that a tremor is on its way, giving people crucial seconds to prepare.

EARTHQUAKE PREPAREDNESS

What Should You Do Before, During, and After an Earthquake?

It is impossible to predict when and where an earthquake will strike. Nonetheless, you can take steps before, during, and after a quake to help yourself stay safe and recover quickly.

Ask a Caltech Expert

Lucy Jones on Earthquakes

Find answers to common questions about earthquakes from seismologist and science communicator Lucy Jones, a visiting associate in geophysics at Caltech and the founder of the Dr. Lucy Jones Center for Science and Society.

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