Drop, Cover, and Hold On
Definition
The internationally recommended protective action during earthquake shaking. Drop to your hands and knees, take cover under sturdy furniture, and hold on until shaking stops.
Example
The Great ShakeOut drill practices Drop, Cover, and Hold On with millions of participants annually.
Related Terms
Related Guides
What Is an Earthquake? A Complete Introduction
Learn what causes earthquakes, how they occur along fault lines, and why some regions experience more seismic activity than others.
Aftershocks Explained: Why Earthquakes Come in Clusters
Aftershocks can continue for months or years after a major earthquake. Learn what causes them, how they're predicted, and when they'll stop.
Can Small Earthquakes Prevent Big Ones?
Small earthquakes do not release enough energy to prevent large ones. Learn the math behind why this popular belief is wrong.
Standing in a Doorway: Why This Advice Is Outdated
Standing in a doorway during an earthquake is outdated advice that can be dangerous. Learn why Drop, Cover, Hold On is safer.
The Big One in California: Separating Fact from Fiction
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Moon Phases and Earthquakes: Is There a Connection?
Tidal forces from the moon have a tiny effect on earthquake triggering. Learn what research shows about lunar influence on seismicity.
Triangle of Life vs Drop Cover Hold On
The Triangle of Life theory contradicts scientific consensus. Learn why Drop Cover Hold On remains the recommended earthquake safety action.
The Complete Earthquake Preparedness Checklist
A comprehensive, step-by-step earthquake preparedness checklist covering supplies, home safety, communication plans, and financial protection.
Drop, Cover, and Hold On: The Right Way to React
Drop, Cover, and Hold On is the proven earthquake safety action. Learn the correct technique and why alternatives like doorways are dangerous.
What to Do During an Earthquake: Indoor Safety
Know exactly what to do during earthquake shaking when you're indoors. Covers homes, offices, stores, elevators, and other indoor scenarios.
Frequently Asked Questions
The epicenter is the point on the Earth's surface directly above the hypocenter (focus) where the earthquake rupture begins. It is typically reported as latitude and longitude coordinates. The strongest shaking usually occurs near the epicenter, though local soil conditions and fault geometry can shift the zone of maximum damage.
A seismograph (or seismometer) is an instrument that detects and records ground motion caused by seismic waves. Modern broadband seismometers can detect movements smaller than the width of an atom. Networks of seismographs around the world enable scientists to locate earthquakes and determine their magnitude within minutes.
P-waves (primary waves) are compressional waves that travel fastest through rock, arriving first at seismic stations. S-waves (secondary waves) are shear waves that arrive later but cause more ground shaking. P-waves travel through solids, liquids, and gases; S-waves only travel through solids. The time difference between them helps determine earthquake distance.
The hypocenter (or focus) is the point within the Earth where an earthquake rupture initiates. It is described by latitude, longitude, and depth. The vertical distance between the hypocenter and the surface directly above is the earthquake's depth, which strongly influences how the earthquake is felt at the surface.
Seismology is the scientific study of earthquakes and the propagation of seismic waves through the Earth. It encompasses earthquake detection, location, and characterization; Earth's internal structure; seismic hazard assessment; and earthquake engineering. Seismologists use data from global seismograph networks to study these phenomena.