Shaping the Face of Earth – The Lithosphere We are going to focus on the Lithosphere Lithosphere: the layer of earth that contains the earth's crust, Tectonic plates This is where earth’s surface is shaped the processes and events that take place here form mountains, volcanoes, spread the ocean floor, make new crust, and many other features. How?......

Shaping and Changing Earth’s Surface – Tectonic Plates Tectonic Plates play a major role in shaping and changing earth’s surface Tectonic Plates: Broken Pieces of lithosphere that move on top of the mantle on convection currents 2 types of tectonic plates: Crustal Plates – lie under continents Oceanic Plates – lie under Oceans Processes of tectonic plates creates and shapes much of earth’s crust

Shaping and Changing Earth’s Surface – Tectonic Plates There are 6 Crustal or Continental Plates that lie under continents North American Plate African Plate South American Plate Eurasian Plate Indo-Australian Plate Antarctic Plate You can identify crustal plates by the continents they lie under!!

Shaping and Changing Earth’s Surface – Tectonic Plates There is 1 major oceanic plate The Pacific Plate Smaller oceanic plates include: Scotia plate Cocos Plate Nazco plate Carribean plate Juan De Fuca plate

Shaping and Changing Earth’s Surface – Tectonic Plates History of Moving Plates: Alfred Wegner proposed the theory of Continental Drift in early 1900’s He says that Millions of years ago, Pangea existed. Pangea: supercontinent where all the continents where all one single large land mass He Theorized that they moved apart by continental drift Continental Drift: is the very slow movement of continental plates that move the continents along with them.

Shaping and Changing Earth’s Surface – Tectonic Plates This continental drift occurs because of plate movement on liquid convection currents This theory is supported by fossils that have been found on two different continents that suggest the two landmasses were once connected Just so you know it really wasn’t Scrat who caused the continental Drift!!

Shaping and Changing Earth’s Surface – Tectonic Plates So moving tectonic plates on convection currents of magma cause continental drift Continents only move a few centimeters a year Tectonic plates also form geologic features and new crust Tectonic plates also cause geological events to occur that change the face or surface of earth.

Shaping and Changing Earth’s Surface – Tectonic Plates Geologic Features – objects or structures that form on earth due to earth’s processes and systems Examples: Mountains, Rocks, Soil, Volcanos, Trenches, Islands, Continents, Mid-Ocean Ridges Geological Events – things that have happened that caused change to structures and features on earth Examples: Earthquakes, Volcanic Eruptions, Tsunamis, sea-floor spreading, subduction Occur mostly at plate boundaries