Grade 7 - NGSS - CA
Aftershock
A smaller earthquake that follows a bigger one. Aftershock. An aftershock is a smaller earthquake that happens after the main earthquake as the ground settles.
Earthquake
A sudden shaking of rock in the Earth's crust. Earthquake. An earthquake is when the ground shakes because rocks underground suddenly move.
Flood plain
A wide valley through which a river flows and can overflow. Flood plain. A flood plain is flat land near a river that can get covered with water when the river spills over its banks.
Hurricane
A large tropical storm with winds of more than 74 mph is called a hurricane. A hurricane is a big spinning storm that forms over warm ocean water and can cause strong winds and rain.
Landslide
The sudden movement of loose rock and soil down a slope. Landslide. A landslide is when dirt and rocks fall down a hill quickly due to gravity and other forces.
Richter scale
A measurement of earthquake magnitude, based on seismic wave size. Richter scale. The Richter scale measures how strong an earthquake is by looking at the size of its seismic waves.
Seismic wave
An energy wave caused by an earthquake. Seismic wave. Seismic waves are vibrations that travel through the Earth when the ground shakes during an earthquake.
Seismograph
An instrument that records seismic waves. Seismograph. A seismograph is a tool that measures and records the shaking of the ground during an earthquake.
Tsunami
A huge wave caused by an underwater earthquake. Tsunami. A tsunami is a large ocean wave that can flood areas when an earthquake occurs under the sea.
Volcano
A mountain through which lava flows to Earths surface. Volcano. A volcano is an opening in Earth's surface where magma, gases, and ash can escape.
