2nd Term LITHOSPHERE

Continents Adrift

Alfred Wegener a German scientist who developed the theory of Continental Drift studied the shapes of the present day continents and noticed how easily they fit together like a puzzle also reviewed studies that showed matching fossil evidence of identical species in two different ends of the globe he wondered how the same species of animals, hundreds of years ago were found on landforms across the ocean

He believed that all of the continents were once joined as a large landmass known as "Pangaea", meaning All-Earth or Supercontinent. This theory can explain why the continents seemed to break apart from each other as pieces of a puzzle. It also provides evidence for how identical species of life can be found across the present day continents.

Although his theory seemed believable, he wasn't sure how the continents began to drift apart. Over time, he studied how volcanoes, earthquakes, mountains, etc. change the shape of the Earth. He suggested that these natural disasters occurred because the entire Earth was covered with "plates" that float on the surface over the hot churning mantle.

Plate Tectonics

Plate Tectonics Plate Tectonics is another theory that explains how the surface of the Earth changes over time. These plates float on the hot mantle below the crust. As convection currents within the magma rise and fall, the crust (or plates) above the mantle, also shift. The continents have shifted since the formation of the Earth and continue to move even today. Almost at the speed of growing fingernails; we can't feel it happening but we know it does. Earthquakes, mountains, volcanic eruptions, etc. are all evidence that the plates on Earth continue to shape the surface of our planet.

Reminder: Earth´s Layers

Theory of Tectonic Plates Plate tectonics is the theory that Earth's outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core. The plates act like a hard and rigid shell compared to Earth's mantle

What do you think? As the plates on Earth continue to move, what do you think our Earth will look like 100 million years from today?

Earth 100 Million Years From Now

Questions (in your notebook) Who is Alfred Wegener & Why is he so important to us? Explain with your own words what “Pangea” means? How do you think earth will look in 100 million years? What are tectonic plates? Give an example of evidence that plates on Earth continue to shape the surface of our planet. Have you ever experience an earthquake, how was it? Do you know what to do in case of an earthquake?