Please do the Audio Setup Wizard! PLATE TECTONICS Science with Mr. Gluckin 11/14/2012 Please get a piece of paper & something to write with. Questions Ohio Content Standard Earth and Space Sciences E Describe the processes that contribute to the continuous changing of Earth's surface (e.g., earthquakes, volcanic eruptions, erosion, mountain building and lithospheric plate movements). I know how mountains, volcanos and valleys are formed. Today s Session KEY WORDS Today s Topics Time scale Continental drift Plate Tectonics Plate Boundaries Coming Events Study Island tectonic plate convection fault hotspot mid ocean ridge subduction volcano geyser earthquake 1
Time Scales Can you see a tree grow? Or the grass? Or your fingernails? Geological Time is verrrry slow! Continents move, but very slowly. Just a few centimeters per year. No, but you see the result after the passage of time. What events on the earth are very slow? What events on the Earth are very fast? Question? Look at the map below, do see any puzzle pieces, if so where would they fit? Now do you see? 2
Historical Perspective The locations of certain fossil plants and animals on present day, widely separated continents would form definite patterns (shown by the bands of colors), if the continents are rejoined. Wegener, 1912: Shapes of continents and fossils Theory of Continental Drift Continental Drift was generally rejected. Wegener could not come up with a way for the continents to actually move. After his death, new evidence from ocean floor exploration and other studies rekindled interest in Wegener's theory, ultimately leading to the development of the theory of plate tectonics. Map of Earth's Tectonic Plates http://www.youtube.com/watch?v=t1 ces1ekto What happens at plate boundaries? The border between two tectonic plates is called a boundary. All the tectonic plates are constantly moving very slowly around the planet, but in many different directions. Some are moving toward each other, some are moving apart, and some are sliding past each other. Because of these differences, tectonic plate boundaries are grouped into three main types. http://www.learner.org/interactives/dynamicearth/plate.html "Ring of Fire Volcanic activity is common at convergent plate boundaries. 3
What was the first theory that involved moving continents called? A. Continental movement theory B. Continental drift theory C. Continental puzzle theory D.Continental float theory What was the first theory that involved moving continents called? A. Continental movement theory B. Continental drift theory C. Continental puzzle theory D.Continental float theory This movement of plates causes stress in some parts of the crust, especially at the boundaries where two different plates are touching each other. Faulting: The stress along a fault is released when the pieces of crust move. The rocks rubbing together can cause an earthquake. Kinds of faults Earthquakes http://www.iris.edu/hq/programs/education_a nd_outreach/animations/2 4
Tsunamis Folding Large areas of folding may form valleys or mountains. There are many places on Earth's surface where the outward transfer of Earth's internal heat is concentrated. Often, these areas are hotspots, which are areas of concentrated, longlasting volcanic activity. Hot Spots Current research is exploring whether hotspots remain fixed in position or shift locations. Geysers Exit Quiz Hydrogeologic features called geysers are often found at hotspots, as well as at areas of volcanic activity in general. Geysers are eruptions of hot water from the ground. 5
Science Zone Tuesdays and Thursdays 4pm 5pm Come get your questions answered about the lesson or about Study Island. Remember to complete your Study Island lesson for this week by 4pm Thursday! Eighth Grade 2F: Plate Tectonics FILE TRANSFER Today s Slides 1. QUESTIONS / DISCUSSION If you have a question raise your hand. 2. 3. Next use the polling tool If you have a working microphone and you have done the audio set up give me a green check. If not then give me a red x. People with a red x can type their question in the chat box but don t send it until it is your turn. 6