Earth structure and composition

1. Earth structure and composition Structure of Earth

2. Earth size and shape • Earth is almost spherical, or ball-shaped, however its shape is not perfect. • Earth is a little flattened at its poles and bulges a bit at its equator

3. Earth Profile • Mass = 5,882 sextillion metric tons • Volume = 1,083 billion Km3 • Total surface Area = 510 million km2 • Land Area = 149 million Km2 • Water Area = 361 million km2

4. Structure of earth • Earth is made of several materials, which make up different layers. • Earth has four different known layers. • Crust • Mantle • Core • Outer core • Inner core

5. The crust • The Earth’s outermost layer • Earth’s crust is made up of: • Soil • Rocks • Silicon and oxygen (primary elements) • Aluminum • Calcium….

6. The crust • Thickness: • 5 to 10 km beneath the oceans • 20 to 70 km beneath the continents

7. The Mantle • Thickness: About 2900 km • High temperatures (2800 to 3200C)

8. Outer core • Thickness: About 2250 km • Made up mostly of melted iron and nickel • Temperatures between 4000 to 5000 C

9. Inner core • Thickness: About 1280 km • Made up of solid iron and nickel • Temperature estimated at 6000 • Note: Although the inner core is very hot, it is kept solid due to the great pressure of layers above it

10. Other resources • http://www.youtube.com/watch?v=NAHY6965o08 • http://www.youtube.com/watch?v=Q9j1xGaxYzY • http://www.youtube.com/watch?v=3MFr2cC3erk

11. Latitude and Longitude • Mapmakers use a set of imaginary lines that cross each other to identify places on earth. • Latitude • Longitude

12. Latitude • Circle Earth in a east-west direction • The central line of latitude, the equator, divides Earth into the northern and southern hemispheres • It is the distance of a place north or south of the equator measured in degrees

13. Longitude • Circle Earth in a north-south direction • It is the distance of a place east or west of the prime meridian • Prime meridian is the central line of longitude, which divides Earth into an eastern and western hemisphere

14. Latitude and longitude

15. Rocks • Rocks are solid Earth materials formed from a mixture of minerals and sometimes other materials. • They are classified into one of the three groups based on how they are formed

16. Groups of rocks • The three groups of rocks are: • Igneous rocks • Sedimentary rocks • Metamorphic rocks

17. Igneous Rocks • How are Igneous rocks formed? • High temperatures deep in Earth’s crust cause rocks and minerals to melt, forming magma • When magma reaches Earth’s surface it becomes lava • Igneous rocks form when magma or lava cools and become solid

18. Igneous Rocks • Some Igneous rocks form from quickly cooled lava • They are called extrusive or volcanic (such as rhyolite) • Some igneous rocks form from slowly cooled lava • They are called intrusive or plutonic ( such as granite)

19. Sedimentary rocks • What is sediment? • Give some example of sediment • Pieces of rocks • Minerals • Remains of living things • Dissolved minerals that come out of water

20. Sedimentary rocks • Sedimentary rocks form when sediment becomes solid material • How are sedimentary rocks formed? • Sediment is moved by wind and water and piles up on land and riverbed, lake bottoms and the ocean floor. New layers of sediment build up over time pressing down on older layers underneath.

21. Types of sedimentary rocks • There are three types of sedimentary rocks. • Clastic sedimentary rocks • Chemical sedimentary rocks • Organic sedimentary rocks

22. Clastic Sedimentary Rocks • Sandstone • Shale • Many kinds of limestone

23. Chemical Sedimentary rocks • Rock salt • Forms when minerals come out of solution and settle on the ocean floor.

24. Organic sedimentary Rocks • Chalk • Forms from the remains of once-living things

25. Metamorphic rocks • Metamorphic rock is rock that has been changed in form by pressure and heat. • Gneiss and slate • Over time, heat and pressure inside Earth squeeze and melt existing rocks. This process changes the grain size and even the minerals that make up those rocks.