Dynamic Earth Webquest

Dynamic Earth Interactive Dynamic Earth Webquest Link Earth's Structure Mouse over the diagram to respond to the following questions. Drag a line to the correct choice. Indicate the thickness, IN MILES, of the following layers: Crust under oceans 3 miles Mantle 1,800 miles Crust under continents 20 miles Outer core 1,400 miles Inner core 750 miles Label the following picture: Use all LOWER CASE letters and double check your spelling. :)crust, mantle, outer core, and inner core are your options inner core outer core mantle crust Label the following image: Use all LOWER CASE letters and double check your spelling. :)oceanic crust, continental crust, mantle, lithosphere and asthenosphere are your options oceanic crust continental crust lithosphere asthenosphere mantle Use the website to help fill in the blanks. The lithosphere - Made up of the crust and a tiny bit of the upper mantle, this layer is divided into several constantly (very slowly) moving plates of solid rock that hold the continents and oceans. Use the website to help fill in the blanks. The asthenosphere - The plates of the lithosphere move (or float) on this hot, malleable semi-liquid zone in the upper mantle, directly underneath the lithosphere. Match the state of matter with the earth's layers: Crust Solid rock Mantle Semisolid rock Outer core Liquid metal Inner core Solid metal Click 'Next chapter: Plate tectonics'Use the website to help fill in the blanks In the early 1900s, the German scientist Alfred Wegener noticed that the coastlines of Africa and South America looked like they might fit together. He also discovered evidence that the same plant and animal fossils were found along the coasts of these continents, although they were now separated by vast oceans. In addition, he noticed that geologic formations, like mountain ranges, on the two continents also matched up. In 1915, Wegener published his book, The Origin of Continents and Oceans, suggesting that the earth's continents were once joined together in one large mass. He called the original landmass (or supercontinent) "Pangaea," the Greek word for "all the earth." According to Wegener, over time "Pangaea" split apart and the different landmasses, or continents, drifted to their current locations on the globe. While other scientists of the time vehemently rejected Wegener's ideas, they became the basis for the development of the theory of plate tectonics. Continents on the move Match the actions with the timeline 200 million years ago Pangaea begins to break up and splits into two major landmasses — Laurasia in the north, made up of North America and Eurasia, and Gondwana in the south, made up of the other continents. 135 million years ago Gondwana splinters further — the South America-Africa landmass separates from the Antarctica-Australia landmass. The Indian landmass breaks away from the Antarctica-Australia landmass. 65 million years ago Major rifting of Laurasia, with the North American landmass separating from Eurasia. South America and Madagascar separate from Africa. 50-40 million years ago Greenland separates from North America. Australia separates from Antarctica and moves north. The Indian landmass collides with Asia. Use the website to help fill in the blanks. The modern plate tectonics theory, which has become widely accepted since the 1960s, states that the earth's outer layer, or lithosphere, is broken into several large slabs called plates. These plates, which hold the continents and oceans, are slowly but constantly moving around the planet. The movement of the plates not only supports our understanding that continents are not fixed and moved over time, but also explains how and why earthquakes, volcanoes, and other geologic events occur. Click on 'continents over time' and complete the activity.Click 'plates and boundaries' Drag the descriptions of the two types of crust to their correct sections. Continental Crust Under continents Thicker About 20-40 miles thick Older crust Oceanic Crust Under oceans Thinner 4-6 miles thick Younger crust Match the vocabulary word with the definition. Boundary The border between two tectonic plates Convergent Boundary Occurs where two plates are pushing toward each other. Divergent Boundary Marks two plates that are moving apart from each other. Transform Boundary Occurs where two plates slide past each other. Example of convergent boundaries include the boundary between the Eurasian Plate and the Indian Plate at the Himalayas Examples of divergent boundaries include the Mid-Atlantic Ridge, made up of the boundary between the North American and Eurasian Plates Examples of transform boundaries include the boundary between the Pacific Plate and the North American Plate in California Click 'Plates and Boundaries Challenge' and complete the challenge.Click 'See what happens @ different plate boundaries' Match the term with the description Volcanic Arc A arc-shaped chain of volcanoes formed above a subduction zone. Subduction The area where one plate is being pulled under the edge of another. Trench A steep-sided depression in the ocean floor. Oceanic Crust The earth's crust found underneath the oceans. Volcano A vent in the earth's surface through which magma and gases erupt. Continental Crust The earth's crust that makes up the continents. Lithosphere Rigid outer layer of the earth broken up into the tectonic plates. Asthenosphere A hot, semiliquid zone on which the tectonic plates float. Magma Molten rock, gases, and solid crystals and minerals. Tsunami a huge ocean wave caused by a sudden shift on the ocean floor Click 'next'Use the website to help you fill in the blanks. At divergent boundaries, tectonic plates are moving away from each other. But if these huge masses of crust are moving apart, what happens in the space left between them? Seafloor SpreadingDivergent boundaries in the middle of the ocean contribute to seafloor spreading. As plates made of oceanic crust pull apart, a crack in the ocean floor appears. Magma then oozes up from the mantle to fill in the space between the plates, forming a raised ridge called a mid-ocean ridge. The magma also spreads outward, forming new ocean floor and new oceanic crust. RiftsWhen two continental plates diverge, a valleylike rift develops. This rift is a dropped zone where the plates are pulling apart. As the crust widens and thins, valleys form in and around the area, as do volcanoes, which may become increasingly active. Early in the rift formation, streams and rivers flow into the low valleys and long, narrow lakes can be created. Eventually, the widening crust along the boundary may become thin enough that a piece of the continent breaks off, forming a new tectonic plate. At this point, water from the ocean will rush in, forming a new sea or ocean basin in the rift zone.Watch the video *** Use the website to help you fill in the blanks. At transform boundaries, tectonic plates are not moving directly toward or directly away from each other. Instead, two tectonic plates grind past each other in a horizontal direction. This kind of boundary results in a fault — a crack or fracture in the earth's crust that is associated with this movement. Faults and EarthquakesTransform boundaries and the resulting faults produce many earthquakes because edges of tectonic plates are jagged rather than smooth. As the plates grind past each other, the jagged edges strike each other, catch, and stick, "locking" the plates in place for a time. Because the plates are locked together without moving, a lot of stress builds up at the fault line. This stress is released in quick bursts when the plates suddenly slip into new positions. The sudden movement is what we feel as the shaking and trembling of an earthquake.The motion of the plates at a transform boundary has given this type of fault another name — a strike-slip fault. The best-studied strike-slip fault is the San Andreas Fault in California. It is located at the boundary between the Pacific and North American plates and runs roughly 800 miles (1,300 km) through Northern and Southern California. As the two plates grind past each other — the Pacific Plate moving northwest and the North American Plate moving southeast — the motion produces numerous earthquakes along the fault. While many are small and cause only minor trembling, the San Andreas Fault has also been the site of major events: the 1857 Fort Tejon earthquake, the 1906 San Francisco earthquake and fire, and the 1989 Loma Prieta earthquake. Many scientists believe that the San Andreas Fault is due to unleash another large earthquake — a "big one" — in the coming decades.Click 'plate interactions challenge' Complete the 'test your skills' Type your score below