Dynamics of Earth Eagle County Charter Academy动态地球县特许学院.pptVIP

Plate Tectonics Dynamics of Earth (Lesson 2) Journal How does the Earth’s surface spread or move? Why? Dynamics of Earth Objectives: 4.1 a, 4.1 b, 4.3 a, 4.4 a, 4.5 a, 4.6 a, 4.6 b Dynamics of Earth Point: It was clear to scientist that seafloor spreading showed that more than just continents were moving. It showed that sections of the seafloor and continents move in relation to one another. Dynamics of Earth Notes: Plate Tectonics: The theory, developed in the 1960s, that states the Earth’s crust and part of the upper mantle are broken into sections. Plates: The broken up sections. Dynamics of Earth Point: The plates move on a plastic like layer of the mantle Dynamics of Earth Review: Layers of The Earth Dynamics of Earth Earth’s Layers Dynamics of Earth Layers continued Dynamics of Earth Notes: Composition of plates: they are made of the crust and a part of the upper mantle Lithosphere: rigid layer of Earth, about 100 km thick, made of the crust and a part of the upper mantle. Dynamics of Earth Notes: Asthenosphere: The plastic like layer below the lithosphere. The rigid plates of the lithosphere float and move around the asthenosphere. Dynamics of Earth Point: When plates move they can interact in several ways. They can collide into one another; they can pull apart; and they can slide alongside on another. When plates interact, the result of their movement is seen at the plate boundaries. Dynamics of Earth Map of the Plates Dynamics of Earth Map of the Plates Dynamics of Earth Map of the Plates Dynamic of Earth Question: Why do the plates move? Dynamics of Earth Answer: It is like heating up soup. Hot less dense material is forced upward by the surrounding, cooler material. As the hot material moves up it cools and sinks back down. It is a convection current!! Dynamics of Earth Note: A convection current is when less dense matter rises and more-dense matter sinks causing a cycle. Dynamics of Earth Point: It all relates back to th