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Dynamic Earth Interactive
Name: __________________________________________________ Date: ________________________ Period: ___________
Go to the following link to start the activity http://www.learner.org/interactives/dynamicearth/index.html. Introduction Our planet might seem fixed and rigid, but a closer look reveals that it is constantly _______________ under our feet. Delve into the earth's interior, learn about its tectonic plates and their movements, and discover how mountains, volcanoes, and _____________________ are formed. Earth’s Structure What’s inside the Earth? In the early part of the 20th century, geologists studied the vibrations (_______________ ___________) generated by earthquakes to learn more about the structure of the earth's interior. They discovered that it is made up of these distinct layers: the crust, the mantle, and the core. The Earth’s outermost and thinnest layer that is hard and rigid is known as the _________________. This layer of the Earth is subdivided into two regions and is made of hot semi‐solid rock. _______________________ This layer is the only true liquid layer of the Earth. It is a sea of mostly iron and nickel. _________________________ An extremely hot, solid sphere made of iron and nickel found at the center of Earth is called _____________________. Plate Tectonics In the early 1900s, the German scientist, ________________ _______________,noticed that the coastlines of Africa and South America looked like they might ______________ __________________. He also discovered evidence that the same ____________ and _____________fossils were found along the coasts of these continents, although they were now separated by vast oceans. In addition, he noticed that _________________________ _______________________, 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 _________________________________________________ in one large mass. He called the original landmass (or supercontinent) "Pangaea," the Greek word for "___________________________________." 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 ___________________ ____________________. Continents on the Move (summarize below) 200 million years ago 135 million years ago 65 million years ago 50‐40 million years ago The modern plate tectonics theory, which has become widely accepted since the 1960s, states that the earth's outer layer, or_________________________, 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. What do some scientists predict will happen to our constantly moving tectonic plates in the future? _________________ __________________________________________________________________________________________________ What is the name of the massive new landmass? __________________________________________________________ Plates & Boundaries As you can see on the map, some of the plates contain __________________ and others are mostly under the _____________. The type of crust that underlies the continents is called continental crust, while the type found under the oceans is called oceanic crust. Continental crust is thicker — about 20 to 40 miles (35 to 70 km) thick — and usually older than oceanic crust, which is only 4 to 6 miles (7 to 10 km) thick. All the plates have names, usually referring to landmasses, oceans, or regions of the globe where they are located. 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. Give at least two examples of each plate boundary. Convergent 1. 2. Divergent 1. 2. Draw arrows at each plate boundary to show what direction the plates are moving. Transform 1. 2. Slip, Slide, & Collide Red‐hot lava and plumes of ash spew out of a volcano in the _____________________. An undersea earthquake in the Indian Ocean spawns a ____________________ that crashes into Indonesia. The __________________Mountains grow taller every year. Many of the most dramatic geological phenomena we experience on Earth — volcanic eruptions, earthquakes, tsunamis, and more — are caused by the slipping, sliding, and colliding of tectonic plates. As you might expect by now, most major geologic events occur at the boundaries between tectonic plates, where huge, massive pieces of the earth's crust _______________. Each kind of plate boundary is associated with particular events, so if you know about the movements taking place at a plate boundary, you can often ________________ what's likely to occur there — volcanoes, earthquakes, mountains, trenches — in the future! Convergent Plate Boundaries – Colliding Plates At convergent boundaries, tectonic plates __________________________ with each other. The events that occur at these boundaries are linked to the types of plates — oceanic or continental — that are interacting Zones What happens? What is a result? Specific Example Subduction Zones (oceanic and continental plates) and Volcanoes Subduction Zones (oceanic and oceanic plates) and Island Arcs Collision Zones and Mountains Divergent Plate Boundaries – Spreading Plates At divergent boundaries, tectonic plates are moving __________________ from each other. But if these huge masses of crust are moving apart, what happens in the space left between them? Zones What happens? What is a result? Seafloor Spreading Rifts Transform Plate Boundaries – Grinding Plates At transform boundaries, tectonic plates are not moving directly toward or directly away from each other. Instead, two tectonic plates grind ________________ 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. Zones What happens? What is a result or an example? Faults & Earthquakes ‐
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Do the Plate Interactions Challenge and Lightening Round. Take the test in the “Test Skills Session.” Write your score here: __________ /30