Earth

1. Earth By: Christian Moses

2. Quick Facts  • Earth is the 3rd planet from the sun • The only planet in the milky way with plants • The only planet that experiences changes in the weather • Only known planet to have life

3. Plate tectonics The earth’s crust is composed of plates that are in constant motion because of the convection currents in the Earth’s mantle and outer core. It is this movement, called plate tectonics, that causes earthquakes and volcanoes. The crust is not one piece. It is made up of about twelve pieces that fit together like a puzzle. Some plates make up the ocean floors, some make up the continents. The plates move about six inches a year (about the same rate that our fingernails grow). Most earthquakes occur where two plates meet. This is called a fault line. The earthquake begins in the layer of the called the lithosphere. Volcanoes occur over “hot spots” where magma pushes through the Earth’s crust. The different kinds of plate movements cause earthquakes, volcanoes, and mountains to form.

4. How it moves • The first person to discover the earth moved around the sun was a Italian scientist named Galileo • The gravity from the sun causes the earth to move around it • It takes the earth 365 days to move around the sun ( A year)

5. Moons • Earth has only one moon rotating around it • The moon is lit by the sun reflecting off its surface • The first thing Astronauts landed on in space was the moon

6. Layers/ Cores The earth has many layers also known as cores. The inner core being the hottest and the crust being the coolest The earth has four layers: the crust, mantle, inner core, and outer core. The lithosphere is the crust and the upper part of the mantle. The lithosphere is about 5 to 30 miles deep. The mantle is about 1800 miles thick. The outer core is about 1300 miles thick and the inner core is about 800 miles to the center of the earth. The inner core is a solid layer. Earthquakes start at the lithosphere. The crust is a thin rocky skin. The thinnest part of the crust is under the ocean. The ocean floor is heavy, dense rock and the land is lighter, less dense rock. The upper part of the mantle is cooler than the deep mantle. The deep mantle is very hot because it rides on top of the extremely hot outer core and therefore it causes the mantle and crust to slowly move. The mantle is made of many different rocky materials. - http://www.northstar.k12.ak.us/schools/joy/denali/DAuria/layers.html

7. Bibliography http://oceansjsu.com/images/exp5_interior_earth.gif http://www.uvm.edu/~inquiryb/webquest/fa05/lkenney/ Http://www.google.com Http://www.Photobucket.com http://www.northstar.k12.ak.us/schools/joy/denali/DAuria/layers.html http://www.northstar.k12.ak.us/schools/joy/denali/DAuria/plate_mvmt.html