2Compositional Zones Earth has 2 types of layers or zones: QUESTION: Compositional: what each layer is made ofMechanical or Structural: physical characteristics about each layer, and how they respond to stressQUESTION:Look at this picture and describe how both sides individually classify the layers of the Earth.
3Crust <1% of Earth’s mass Earth’s crust is the thinnest layer. OceanicMade mostly of igneous basaltThin: 5-7 kmContains more iron than continental crust. MAFICEarth’s crust is the thinnest layer.5-100 km thickTwo types of crust :OceanicContinentalContinentalFound under continents.Thick: up to 100 kmMade mostly of granite. FELSIC
4QUESTION:Look at this picture and describe which type of crust (oceanic or continental) is the most dense and why.
5Mantle 68% of Earth’s mass Earth’s mantle is directly above the outer core and starts blow the crust. It is the largest layer and relatively homogeneous. It is made of more iron than the crust. Density, pressure, and temperature all increase the deeper you go in the mantle. Heat is transferred through convection.QUESTION:Explain what you think is happening in the green layer above the mantle.
6Core 31% of Earth’s mass The core has two parts: Inner Outer The outer core is liquid and surrounds the solid inner core.The outer core is made of molten iron and nickel.The inner core is solid iron and nickel.QUESTION:Explain what this picture is demonstrating and how it relates to the core.
7Structural/Mechanical Zones Structural Zones are often thought of their characteristic response to stress.
8Lithosphere Rigid layer The lithosphere is made up of 2 parts: CrustRigid ‘Upper Mantle’It is divided into tectonic plates.QUESTION:Do you think the tectonic plates consist of oceanic, or continental crust, or both.
9Asthenosphere Plastic layer The Asthenosphere is made up of: QUESTION:How does the plasticity in the asthenosphere play a role in plate tectonics?The Asthenosphere is made up of:Plastic ‘Upper Mantle’Plasticity is when a solid rock flows very slowly due to heat and pressure.This is the layer on which tectonic plates move.
11Mesosphere Strong layer ‘Lower Mantle’ The mesosphere is made up of: Comparison to ‘Upper Mantle’Greater densityMore rigidSame chemical compositionQUESTION:As you increase depth in the mantle, what else happens?