Presentation on theme: "On your paper, answer the following question of the day: In the Liquid Layers Lab, the coldest liquid was the most dense. In class you learned that the."— Presentation transcript:
On your paper, answer the following question of the day: In the Liquid Layers Lab, the coldest liquid was the most dense. In class you learned that the core is the most dense as well as hottest layer of Earth. Typically the colder a substance, the more dense it is. Why do you think the core is so hot yet is still the most dense layer. Today’s Schedule 1.? Of the Day 2.Review Liquid Layers Lab 3.Reconstructing Pangaea Lab
What was Pangaea? Has the world always looked as it does today? Continents of the Past. Animation.
What was Pangaea? Pangaea means ‘all land’ in Greek 245 million years ago Earth’s continents were joined together to form a supercontinent known as Pangaea.
Reconstructing Pagaea Lab 1. Label the 7 continents, including Greenland and India, before cutting them out. 2. Outline the edge of each continent with a different color. 3. When you are cutting, cut as close to the edge of the continents as possible. Don’t cut out the islands. 4. Ask Questions if you are confused or need help. 5. Follow the procedure on the Lab Sheet.
Welcome to Science 9/14 Immediately find your partner for the Reconstructing Pangaea Lab and continue working on it. You have about 20 minutes to complete the lab. Today’s Schedule 1. Conclude Pangaea Lab 2. Begin Ch. 7 Section 2 Notes/Discussion
Question of the Day Besides the shape of the continents, what other evidence shown in the map below supports the Pangaea theory?
Welcome to Science 9/15 Have a seat. Get your Reconstructing Pangaea Lab out. Open your book to page 173 and begin completing your notes for Ch. 7 Section 2. Today’s Schedule 1. Notes/Discussion Ch. 7 Section 2 2. Review Reconstructing Pangaea Lab
Restless Continents Ch. 7 Section 2 Restless Continents Restless ContinentsWhat do we mean when we say Restless Continents? Continental drift- theory that continents can drift apart and have done so in the past.
I. Drifting Continents What did Alfred Wegener observe that led him to believe in continental drift? 1. continents fit together like a puzzle 2. Fossils of the same species were found on different continents 3. evidence of rocks and climatic conditions were found on the same continents.
II. Breakup of Pangaea What did Wegener infer based on his evidence? Millions of years ago there was one supercontinent that over time slowly broke apart
III. Wegener’s Theory Rejected Why? Wegener could not conclude how or why the continents moved. What discovery provided clues that Wegener was right?
III. Mid-Ocean Ridge 1960’s underwater worldwide mountain chain was discovered What happens at the mid-ocean ridge that moves the continents? Sea-floor spreading
III. What is sea-floor spreading? As plates diverge magma rises up to form a mid-ocean ridge. As more magma continues to rise and harden it spreads the sea-floor apart. animation
III. Evidence of Sea-floor Spreading How do we know sea-floor spreading is happening? Seafloor Spreading Interactive Seafloor Spreading Interactive Rock samples taken from the sea-floor show that the oldest rocks are further from mid-ocean ridges.
IV. Magnetic Reversals Throughout history Earth’s magnetic fields will switch. Meaning the north pole goes to the south pole and vice versa. Magnetic minerals in magma align with Earth’s magnetic field. When the poles switch this creates stripes or bands that can be seen on the sea-floor. animation