An earthquake is an intense shaking of Earth's surface. A tornado is a spinning column of air. It reaches from a storm cloud down to the ground. A hurricane is a big storm. It forms over warm ocean water. A flood is water that covers land that is usually dry.

Scientists use an instrument called a seismometer. It measures the shaking waves from an earthquake. An earthquake under the ocean can push the water above it. That can start a tsunami. Here is what to do. If the ground shakes, drop down. Cover your head and neck. Hold on until the shaking stops.

A tornado often looks like a funnel. It hangs down from a dark cloud. A tornado watch means tornadoes are possible in and near the area. In a tornado warning, go to a small room with no windows. Go to the lowest floor of a sturdy building.

Now for hurricanes. When a storm's winds reach 74 miles per hour, it is called a hurricane. A hurricane has a calm, clear center. It is called the eye. Each hurricane is given a name. People then know a new storm is on its way.

Floods can come from heavy rain or from fast-melting snow. They can also come when ocean waves come on shore. Never walk, swim or drive through flood water. Weather forecasters send out warnings. People then have time to get to a safe place. A NOAA Weather Radio has a tone alert. It is one way to hear when a warning is issued.

A family can make a plan together. They can pick a place to meet if they are ever apart. A disaster kit holds basic things a family may need. It may hold water and food. It may hold a radio, a flashlight and a first aid kit. A kit should have one gallon of water for each person for each day.

Words to know

• seismometer: shake measurer
• tsunami: big ocean wave
• watch: might happen
• hurricane: big storm
• funnel: cone shape