Changes on Earth

Science, Grade 3

Changes on Earth © Copyright NewPath Learning. All Rights Reserved. 94-4307 crust The Earth is made up of three main layers. We live on the outer layer of the Earth called the crust. The Earth’s crust is made up of many different rocks. The layer beneath the Earth’s crust is called the mantle. The Earth’s mantle is made of igneous and metamorphic rocks. The innermost layer of the Earth is called the core. The Earth’s core is made of metal. The Earth’s core is hot enough to melt but the center of the core is packed together so tightly that it remains a solid. The outer section of the Earth’s core however is hot, thick liquid. core mantle A volcano is an opening in the Earth’s crust which hot, melted rock forcefully comes out of when pressure is built up inside the Earth. Magma is melted rock found beneath the Earth’s surface. Lava is melted rock that comes above the Earth’s surface. An earthquake is a sudden shift in the Earth’s crust that causes the ground to shake and vibrate violently. Most earthquakes happen near faults. Faults are large cracks in the Earth’s crust. glacier mountain lake valley Landforms are many different solid features formed on top of the Earth’s crust; some also involve bodies of water. A glacier is a slow moving large body of ice. A river is a natural flow of water that is larger than a brook or a creek. A lake is a large body of still water surrounded by land. A valley is a low, narrow area that is formed by rivers and glaciers. A hill is an elevated land but it is not as tall as a mountain. A mountain is elevated land that reaches high above the Earth’s surface and is larger than a hill. An ocean is made up of saltwater. Oceans cover just about ¾ of the E arth’s surface. A coast is the land that is right next to the ocean that forms the coastline. river ocean coast A plain is a large, mostly flat area of land. seismic waves focus fault cone cloud of ash pipe magma lava flow dike Images courtesy of USGS, NPS, USFWS. Weathering is the process of rocks breaking into smaller pieces. Water can change the minerals in rocks making the rocks weaker and can cause rocks to weather and to break up into smaller pieces. The movement of land that has been weathered is called erosion. Erosion is caused by water, wind, gravity, and glaciers. plain
\|xiBAHBDy01725nzW Key Vocabulary Terms coast magma core mantle crust mountain earthquake ocean fault plain focus river glacier seismic wave hill valley lake volcano landform weathering lava Changes on Earth © Copyright NewPath Learning. All Rights Reserved. 94-4307 Images courtesy of USGS, NPS, USFWS. Describe the three layers that make up the Earth. ______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________ What are landforms? ________________________________ __________________________________________________ A glacier is _______________________________________ . An ocean is ______________________________________ . A river is _________________________________________ . A lake is _________________________________________ . A coast is ________________________________________ . A valley is ________________________________________ . A plain is ________________________________________ . A hill is __________________________________________ . A mountain is ____________________________________ . What is a volcano? ______________________ ______________________ ______________________ What is the difference between magma and lava? ______________________ ______________________ What is an earthquake? ______________________ ______________________ ______________________ ______________________ ______________________ What is weathering? ____________________________ ____________________________ ____________________________ ____________________________