What Is an Earthquake? An earthquake occurs when there is a sudden and violent shaking of the Earth’s surface, usually caused by the movement of tectonic plates beneath the ground. This movement creates seismic waves that cause the ground to tremble. The intensity of these tremors can range from mild shakes to catastrophic quakes, depending on the magnitude.
How Do Earthquakes Happen? Earthquakes occur along faults, which are cracks in the Earth’s surface where two tectonic plates meet. When pressure builds up along these faults due to the movement of the plates, it can cause the Earth to shift suddenly, releasing large amounts of energy. This energy travels in the form of seismic waves, shaking the ground and structures above.
Earthquake Hazards:
- Ground Shaking: This is the primary hazard during an earthquake, causing buildings to collapse and debris to fall.
- Surface Rupture: Earthquakes can cause cracks or ruptures in the Earth’s surface, damaging roads, railways, and buildings.
- Tsunamis: If an earthquake occurs beneath the ocean, it can trigger massive waves that cause widespread flooding along coastlines.
- Landslides: The shaking of the ground can trigger landslides, especially in hilly or mountainous regions.
Earthquake Warning California
Earthquake Warning California is the country’s first publicly available, statewide warning system that could give California residents crucial seconds to take cover before you feel shaking. Managed by the Governor’s Office of Emergency Services (Cal OES), Earthquake Warning California uses ground motion sensors from across the state to detect earthquakes before humans can feel them and can notify Californians to “Drop, Cover and Hold On” in advance of an earthquake. Learn More
Prepare Before
Being prepared can make a big difference during an earthquake. Here are steps you can take:
- Secure Your Home: Fasten heavy furniture, appliances, and electronics to walls. Install safety latches on cabinets to prevent items from falling.
- Create an Emergency Kit: Keep a kit that includes water, non-perishable food, a flashlight, extra batteries, a first aid kit, a whistle, a multi-tool, and any necessary medications. Have at least 72 hours of supplies.
- Develop a Family Plan: Ensure that every family member knows what to do in the event of an earthquake. Identify safe spots in your home (e.g., under a sturdy table) and establish an emergency meeting place outside.
- Practice Drills: Practice “Drop, Cover, and Hold On” drills with your family to familiarize them with the actions they should take.
Protect Yourself During
When the shaking starts, quick action is critical:
If you are Indoors:
- Drop to your hands and knees to prevent being knocked over.
- Take cover under a sturdy piece of furniture or protect your head and neck with your arms if no shelter is available.
- Hold on until the shaking stops. Stay away from windows and exterior walls.
If You Are Outdoors:
- Move to an open space away from buildings, trees, and power lines. Drop and cover if necessary.
If You Are in a Vehicle:
- Pull over to the side of the road, away from overpasses, bridges, trees, and power lines. Stay inside the vehicle with your seatbelt fastened until the shaking stops.
Stay Safe After
After the shaking stops, it’s important to take the following steps:
- Check for Injuries: Look for injuries in yourself and others. Provide first aid as needed and call emergency services if necessary.
- Expect Aftershocks: Aftershocks are smaller tremors that can occur minutes, hours, or even days after the main quake. Be ready to react quickly.
- Inspect Your Home: Check for hazards such as gas leaks, fires, and structural damage. Don’t use open flames or electrical appliances until you’re sure it’s safe.
- Listen to Authorities: Tune in to local radio, TV, or social media for emergency alerts and evacuation instructions.
Different Types of Alerts
You can receive warning of an earthquake before you feel shaking. Earthquake Warning California can give you seconds of notice using the following tools:
- MyShake App
- Android Earthquake Alerts
- Wireless Emergency Alerts (WEAs)