1 / 24

Structure of the Earth

Structure of the Earth. Chemical Composition Earth is divided into 3 layers: crust, mantle, core Based on compounds that make up each layer Less dense elements & compounds - crust & mantle More dense elements & compounds - core. The Crust. 2 Types – Continental & Oceanic

geraldv
Download Presentation

Structure of the Earth

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Structure of the Earth • Chemical Composition • Earth is divided into 3 layers: crust, mantle, core • Based on compounds that make up each layer • Less dense elements & compounds - crust & mantle • More dense elements & compounds - core

  2. The Crust • 2 Types – Continental & Oceanic • Less than 1% of Earth’s mass & volume • Both share common elements such as: O, Si, Al • Oceanic crust has 2x as much Fe, Ca, Mg

  3. Oceanic crust is thinner AND denser than continental crust.Continental ~2.7g/cm3 Oceanic ~ 2.9g/cm3(made of granite) (made of basalt)

  4. Element Types General distribution by volume (Earth)

  5. Element TypesDistribution within earth’s crust only

  6. Do Now: Compare and contrast the 2 types of crust.What are their names?Compare their densities?What are they made of? (Top 4)

  7. The Mantle • Located between the crust and the core • Most of Earth’s mass & volume is located in the mantle (67% & 83% respectively) • Only physical observations of mantle are when mantle rock is uplifted to the surface (land or ocean floor)

  8. The Core • Extends from below the mantle to the center of the Earth • Made of mostly Fe with some Si & Ni • Approx. 33% of Earth’s mass & 16% volume

  9. Physical Structure of Earth– 5 Layers • Lithosphere means “rock” • made up of 2 parts • Crust • Rigid upper part of the mantle • Divided into pieces called tectonic plates • Approx 0-100km • Approx 1.57% volume

  10. Tectonic plates – a block of lithosphere that consists of the crust and the rigid, uppermost part of the mantle. • Lithosphere- Contains the crust, rigid upper part of the mantle & tectonic plates that seem to fit like a jigsaw puzzle pieces.

  11. Asthenosphere means “weak” • Solid rock that flows very slowly • Upper part of mantle • Plastic layer of the mantle -“malleable” soft – bendable • Pieces of the lithosphere move on top of the asthenosphere • Approx 100-700km • Approx 9.42% volume

  12. Mesosphere means “middle” • Magma layer • Strong, upper part of the mantle • Between asthenosphere and core • Approx 700-2,885km • Approx – 34.30% volume

  13. Mantle/Asthenosphere/Mesosphere Convection • Convection currents from the mantle/mesosphere turn clockwise or counter clockwise • This energy moves the asthenosphere • As the asthenosphere moves, blocks of lithosphere also move, bring tectonic plates along for the ride

  14. Charles Hapgood Crust Displacement Theory • 1950’s • Theory states that lithosphere is not separate pieces that slowly move independently of each other and the rest of the Earth, but move as one piece. • Supported by Einstein • Supported by age of Antarctic ice • Supported by discovery of flash frozen animals (wolley mammoth) • https://www.bibliotecapleyades.net/ciencia/ciencia_earthchanges33.htm

  15. Core – 2 parts • Outer Core • Liquid iron layer of the core • Approx 2,885-5,155km • Approx – 35.64% volume • Inner Core • Solid iron layer of the core • Approx 5,155-6,371km • Approx 19.09% volume

  16. Magnetic Field • The combination of a liquid iron (mostly) outer core which is moving around a solid iron inner core produces Earth’s magnetic field.

  17. Earth’s chemical & physical composition

  18. The Earth’s Crust, Lithosphere, and Asthenosphere Lithosphere Asthenosphere Mesosphere Crust Lithosphere Mantle Asthenosphere Mesosphere

  19. DO NOW: Discuss with a partner & record answers on your PPT Notes Sheet • 1. What layer of physical structure contains all of the tectonic plates? • 2. What layers of physical structure make up the mantle? • 3. What layers of composition make up the lithosphere?

  20. Differences in Tectonic Plates Some plates have: • an entire continent and oceanic crust • only oceanic crust • partial continental & oceanic crust

  21. Some plates have: • an entire continent and oceanic crust • only oceanic crust • partial continental & oceanic crust

  22. Tectonic Plates float on top of the asthenosphere in a similar way that ice floats on the surface of water. • Plates cover surface of asthenosphere, touch one another, and move around. • Lithosphere displaces the asthenosphere • Thick tectonic plates (made of cont. crust) displace more than thin plates (made of oceanic crust)

  23. Mapping the Earth’s Interior • Seismic waves – vibrations caused by earthquakes. • travel at different speeds • speed depends on density and composition of material • faster through solids • faster through denser rock • slower through liquids

  24. Seismographs - measure the times at which different seismic waves arrive and record the differences in their speeds • Scientists use the measurements to calculate the density and thickness of each physical layer of the Earth.

More Related