8/4/2020 CG SCI Science 180 - GradeBook Unit 09: Models of the Earth Text: PDF File MODELS OF THE EARTH Unit Overview This unit will look into the many tools developed by scientists to study our Earth. These tools in turn, have brought about new discoveries and areas of research in Earth science. Many technologies such as satellite global positioning systems and topographic maps are used by everyday people to make their lives comfortable and safe. How Do Scientists Know What's Inside the Earth? Unit Directions Read the following text on Earth models, study the illustrations, complete all activities, and then answer the test questions. Key terms will be in bold type. https://gb.metasolutions.net/Quiz/Question/Summary?quizId=1035GLOSSARY OF KEY TERMS 1/20 8/4/2020 CG SCI Science 180 - GradeBook GLOSSARY OF KEY TERMS contour lines: imaginary lines that connect equal areas of elevation on a topographic map globe: a map of the world or a celestial map on a sphere, allowing for a more accurate representation of the Earth's surface than can be shown on a flat map map: a flat, graphic representation of the Earth model: a simplified description of a complex entity or process oblate spheroid: a spherical shape that is a slightly distorted sphere. The distortion occurs in the middle of the sphere where there is a bulge pure science: the study of the natural world through observation, identification, description, experimental investigation, and theoretical explanations relief maps: maps having shading or color to represent points of different elevation technology: the application of scientific advances to benefit humanity thermodynamics: the study of the processes that involve the transformation of heat from hotter bodies to cooler bodies topographic maps: maps that show natural and man-made features of an area using contour lines (lines of equal elevation) to portray the size, shape, and elevation of the features satellite: any object, man-made or natural that orbits another object What shape is our planet? That sounds like a pretty simple question, right? Most of us would quickly say, “Round.” But the Earth is not perfectly round! It has an oblong shape like all the other planets. This is caused by the spinning of the planets that forces the matter to compress in the middle of the sphere-shaped planetary bodies and a distortion in https://gb.metasolutions.net/Quiz/Question/Summary?quizId=1035 2/20 8/4/2020 CG SCI Science 180 - GradeBook compress in the middle of the sphere shaped planetary bodies, and a distortion in their shape is created. Our Earth is almost a sphere, but not quite, so its shape is an oblate spheroid. Oblate describes the oblong shape and spheroid tells us that the Earth is a nearly sphere-shaped planet. The first picture shows an oblate spheroid from the side. You can see that it is narrower at the top and bottom and wider in the middle. The picture on the right shows a top view of the oblate spheroid. In this view, the shape looks perfectly round. How did scientists prove the oblate spheroid shape? Scientists can not make a statement about the Earth’s shape without evidence. So what is the evidence that supports the oblate spheroid shape? · Pictures from outer space: Astronauts and satellites have provided beautiful photographs that help support the shape theory. It is, however, very hard to detect by looking at photographs because the shape is so close to a perfect sphere. · Measurements: Accurate measurements are kept of the movement of the stars and Sun. The movements of these heavenly bodies would appear differently if the Earth were a perfect sphere. Another set of measurements come from right here on Earth. Scientists collect calculations on gravity’s affect on different objects. As an object moves away from the Earth’s core, its weight changes. If the Earth were perfectly round, the weight of the object would be the same all around the Earth as long as it was measured at the same elevation. On Earth, objects weigh a little more at the poles and a little less at the equator due to the oblate spheroid shape. What types of models are used to represent Earth? https://gb.metasolutions.net/Quiz/Question/Summary?quizId=1035 3/20 8/4/2020 What types of models CGare SCI Scienceused 180 - toGradeBook represent Earth? · A model is a visual representation, a mathematical equation, or a set of rules that let us study an object or concept that is not easily observed. Many times a model is used when an object is too large or too small to study and the model aids in our understanding. For instance, we can not see a single skin cell with the naked eye, so a scientist will use a poster or plaster model of the cell to study its parts and structure. The Earth is too big for us to take in by just looking outside, so we invent physical models to make observations much easier. The globe is a familiar model used by many to look at the complete structure of the Earth. · People use globes for a variety of reasons. We can study the continents of the world, the many bodies of water, latitudinal and longitudinal lines, and political boundaries. A person can study the Earth as a whole using a globe. The globe increases visual accuracy and allows a viewer to create a mental map and see the relationship between continents, oceans, and climatic differences. Size, shape, distance and directions are accurately shown on a globe. Globes do not distort the major features of our Earth. Maps · A map is a flat, graphic representation of the Earth. Maps are drawn for a variety of reasons. Most people are familiar with maps that are used to look up directions for traveling from one place to another. https://gb.metasolutions.net/Quiz/Question/Summary?quizId=1035 4/20 8/4/2020 CG SCI Science 180 - GradeBook · The map above shows the area around Steubenville, Ohio. It displays major roads and the names of towns. The Ohio River is the blue winding line in the middle of the map. Other maps will give us different information. To find rivers in other states, click on the following link: http://www.factmonster.com/ipka/A0001800.html https://gb.metasolutions.net/Quiz/Question/Summary?quizId=1035 5/20 8/4/2020 CG SCI Science 180 - GradeBook · World maps show the entire world at a glance. But because a map is flat, there is distortion in the size, shape and distance of features such as countries and continents. The map above shows the continents and oceans. Other world maps can show political boundaries (countries), seismic activity, and weather patterns. Weather maps detail information that explains weather conditions across a specific area. These maps often come with keys or special symbols that represent the various weather conditions. How are TV Weather Maps Created and Used? (01:23) ACTIVITY: What are the differences between a map and a globe? Materials: You will need a world map, a globe, and a measuring device (preferably a metric ruler). Directions: It is best if you have a world map on which you can draw. Have a pencil and paper ready to write down your observations. Remember that observations include size, shape, texture, and color among other things. https://gb.metasolutions.net/Quiz/Question/Summary?quizId=1035 6/20 8/4/2020 obse vat o s c ude s e, s apeCG, te SCIt uSciencee, a 180d c- GradeBooko o a o g ot e t gs. 1. Find Africa on the globe and then on the world map. Do they look similar? Compare and contrast your observations of Africa. 2. Now complete step #1 again with Antarctica that you completed with Africa. 3. Using the world map circle Greenland and circle the country of Sudan in Africa. Which do you believe is the largest? Now find the same two countries on the globe. Do you still agree with your previous answer on the largest country? Use the internet to find the measurement of the area of Sudan and then Greenland. Which country is actually larger? Did either the globe or the map give you the correct answer on which is largest? 4. Now let’s get you thinking global! Take a few minutes to really study the globe and the location of features. Below is a list of locations on the globe. Can you guess what is on the opposite side of the globe? Write down your guesses and then check your answers at the end of the unit. 1. Antarctica 2. North America (Chicago, IL, USA) 3. Perth, Australia 4. Buenos Aires, Argentina 5. Paris, France 6. Kabul, Afghanistan 7. Kinshasa, Zaire 5. Look at your map again and find Chicago, Illinois and Bombay, India. Draw a line between the two that represents the shortest route to get from Chicago to Bombay. Now check your globe. Would you still travel the same route? Why or why not? 6. Next circle, Buenos Aires, Argentina, and Sydney, Australia on the world map. Repeat the steps in #5 and answer the questions again. · Relief Maps are maps having shading or color to represent points of different elevation. This type of map usually contains an explanation or key to help a user read the map. The map below is a relief map of Arizona. https://gb.metasolutions.net/Quiz/Question/Summary?quizId=1035 7/20 8/4/2020 CG SCI Science 180 - GradeBook The colors indicate elevation above sea level · Orange and red areas in SW AZ are lowest · Blue and purple are higher · Green and brown areas in N and E AZ are even higher · The isolated pink color mountain areas are the highest.